fundamentals of industrial hygiene

Study Guide Answers

Fundamentals of Industrial HygieneFifth Edition

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©2002 National Safety Council

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Copyright 2002 by the National Safety CouncilAll Rights ReservedPrinted in the United States of America06 05 04 03 02 1 2 3 4 5

ISBN: 0-87912-237-4

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ii©2002 National Safety Council

FIH Study Guide Answers

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Contents1 Overview of Industrial Hygiene 1

2 The Lungs 4

3 The Skin and Occupational Dermatoses 5

4 The Ears 8

5 The Eyes 10

6 Industrial Toxicology 12

7 Gases, Vapors, and Solvents 14

8 Particulates 17

9 Industrial Noise 19

10 Ionizing Radiation 21

11 Nonionizing Radiation 24

12 Thermal Stress 26

13 Ergonomics 28

14 Biological Hazards 31

15 Evaluation 34

16 Air Sampling 36

17 Direct-Reading Instruments for Gases, Vapors, and Particulates 38

18 Methods of Control 40

19 Local Exhaust Ventilation 43

20 Dilution Ventilation of Industrial Workplaces 45

21 General Ventilation of Nonindustrial Occupancies 46



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22 Respiratory Protection 49

23 The Industrial Hygienist 52

24 The Safety Professional 54

25 The Occupational Medicine Physician 56

26 The Occupational Health Nurse 58

27 The Industrial Hygiene Program 60

28 Government Regulations 62

29 History of the Federal Occupational Safety and Health Administration 65


Chapter 1 Overview of IndustrialHygiene ANSWERS—Quiz 1

1. b

2. a

3. a

4. a

5. b

6. b

7. b

8. b

9. a

10. b

11. c

12. c

13. b

14. c

15. b

16. Industrial hygiene is the science and art devotedto the anticipation, recognition, evaluation, andcontrol of those environmental factors or stressesarising in or from the workplace that may causesickness, impaired health and well-being, or sig-nificant discomfort among workers or amongthe citizens of the community.

17. The groups include the American Conference ofGovernmental Industrial Hygienists (ACGIH),American Academy of Industrial Hygiene(AAIH), American Board of Industrial Hygiene(ABIH), and American Industrial Hygiene Association (AIHA).

1 • Overview of Industrial Hygiene

1

18. Student should name three of the following: theindustrial hygienist, the safety professional, theoccupational health nurse, the occupationalmedicine physician, the employees, senior andline management, and others depending on thesize and character of the facility.

19. The industrial hygiene program must be made up of several key components: a writtenprogram/policy statement, hazard recognitionprocedures, hazard evaluation and exposureassessment, hazard control, employee training,employee involvement, program evaluation andaudit, and record keeping.

20. Employees are excellent sources of informa-tion on work processes and procedures and thehazards of their daily operations. The indus-trial hygienist benefits from this source of information and often obtains innovative sug-gestions for controlling hazards.

21. The OSHAct sets out two duties for employers:Each employer shall furnish to each employeea place of employment which is free from rec-ognized hazards that are causing or are likely tocause death or serious harm to their employees.Each employer shall comply with occupationalsafety and health standards under the act.

22. A Health Hazard Evaluation is an on-the-jobinvestigation of reported worker exposures thatare carried out in response to a request by eitherthe employer or the employee or employee rep-resentatives.

23. The severity of a hazard in the use of organicsolvents and other chemicals depends on the fol-lowing factors: how the chemical is used; typeof job operation, which determines how theworkers are exposed; work pattern; duration ofexposure; operating temperature; exposed liq-uid surface; ventilation rates; evaporation rateof solvent; pattern of airflow; concentration ofvapor in workroom air; and housekeeping.

24. The Canons of Ethical Conduct are as follows:Canon 1: Industrial Hygienists shall practicetheir profession following recognized scientificprinciples with the realization that the lives,health, and well-being of people may dependupon their professional judgment and that theyare obligated to protect the health and well-being


of people. Canon 2: Industrial Hygienists shallcounsel affected parties factually regardingpotential health risks and precautions necessaryto avoid adverse health effects. Canon 3: Indus-trial Hygienists shall keep confidential personaland business information obtained during theexercise of industrial hygiene activities, exceptwhen required by law or overriding health andsafety considerations. Canon 4: IndustrialHygienists shall avoid circumstances where acompromise of professional judgment or con-flict of interest may arise. Canon 5: IndustrialHygienists shall perform services only in theareas of their competence. Canon 6: IndustrialHygienists shall act responsibly to uphold theintegrity of the profession.

25. The four environmental factors or stresses areas follows:

(1) Chemical hazards arise from excessive air-borne concentrations of mists, vapors, gases,or solids in the form of dusts or fumes. Inaddition to the hazard of inhalation, some ofthese materials may act as skin irritants ormay be toxic by absorption through the skin.

(2) Physical hazards include excessive levels ofnonionizing radiation, ionizing radiation,noise, vibration, and extremes of tempera-ture and pressure.

(3) Ergonomic hazards include improperlydesigned tools, work areas, or work proce-dures. Improper lifting or reaching, poorvisual conditions, or repeated motions in anawkward position can result in accidents orillnesses in the occupational environment.

(4) Biological hazards are any living organismor its properties that can cause an adverseresponse in humans. They can be part of thetotal environment or associated with a par-ticular occupation.

ANSWERS—Quiz 2

1. b

2. b

3. a

4. b

5. a


2

6. a

7. b

8. c

9. b

10. a

11. c

12. c

13. a

14. b

15. c

16. The safety and health committee provides aforum for securing the cooperation, coordina-tion, and exchange of ideas among thoseinvolved in the health and safety program. Thetypical functions of the safety and health com-mittee include: to examine company safety andhealth issues and recommend policies to man-agement, conduct periodic workplace inspec-tions, and evaluate and promote interest in thehealth and safety program.

17. The key elements to consider are (1) the route ofentry of the chemical into the body, (2) how muchof the material is required to be in contact witha body cell to produce injury, (3) the probabilitythat the material will be absorbed or come in con-tact with body cells, (4) the rate of generation ofairborne contaminants, (5) the control measuresin place, and (6) the total time of contact.

18. The effects of noise on humans include the fol-lowing: psychological effects (noise can startle,annoy, and disrupt concentration, sleep or relax-ation); interference with speech communicationand, as a consequence, interference with job per-formance and safety; and physiological effects(noise-induced hearing loss or aural pain whenexposure is severe).

19. The following factors can influence the effect ofthe noise exposure: variation in individual sus-ceptibility; total energy of the sound; frequencydistribution of the sound; total daily duration of


exposure; length of employment in the noiseenvironment; other characteristics of the noiseexposure, such as whether it is continuous, inter-mittent, or made up of a series of impacts.

20. The signs for heat exhaustion include mildly ele-vated temperature, pallor, weak pulse, dizziness,profuse sweating, and cool, moist skin.

21. Certain radioactive materials can be hazardouseven when located some distance away from thebody; these are external hazards. Other typesare hazardous only when they get inside thebody through breathing, eating, or broken skin.These are called internal radiation hazards.

22. Electric welding arcs and germicidal lamps arethe most common strong producers of ultravi-olet radiation in industry. The most commonexposure to ultraviolet radiation is from directsunlight.

23. Barotrauma is a kind of tissue damage resultingfrom expansion or contraction of gas spaceswithin or adjacent to the body, which can occureither during compression or during decom-pression.

24. The respiratory system consists of the nose,mouth, upper throat, larynx, trachea, bronchi,lungs, diaphragm, and muscles of the chest. Res-piratory hazards can be broken down into twomain groups: oxygen deficiency and air that con-tains harmful or toxic contaminants.

25. Factors that affect the degree of eye injuryinduced by laser light include the following: (1) pupil size, (2) the ability of the cornea andlens to focus the incident light on the retina, (3) the distance from the source of energy to theretina, (4) the energy and wavelength of thelaser, (5) the pigmentation of the eye of the sub-ject, (6) the location on the retina where the lightis focused, (7) the divergence of the laser light,and (8) the presence of scattering media in thelight path.

26. The relevant data concerning lifting can be clas-sified into task, human, and environmental vari-ables. (1) Task variables: location of object to belifted, size of the object to be lifted, height fromwhich and to which the object is lifted, frequencyof lift, weight of object, and working position.

1 • Overview of Industrial Hygiene

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(2) Human variables: sex of worker, age ofworker, training of worker, physical fitness orconditioning of worker, and body dimensions ofthe worker. (3) Environmental variables: extremesof temperature, humidity, and air contaminants.

27. To recognize and evaluate environmental healthhazards, ask the following questions: What isproduced? What raw material is used? Whatmaterials are added in the process? What equip-ment is involved? What is the cycle of opera-tions? What operational procedures are used? Isthere a written procedure for the safe handlingand storage of materials? What about dust con-trol, cleanup after spills, and waste disposal? Arethe ventilating and exhaust systems adequate?Does the facility layout minimize exposure? Isthe facility well-equipped with safety appliancessuch as showers, masks, respirators, and emer-gency eyewash fountains? Are safe operatingprocedures outlines and enforced? Is a completehazard communication program that meets stateor federal OSHA requirements in effect?

ANSWERS—Case Study

1. The four major U.S. industrial hygiene organi-zations are the American Conference of Gov-ernmental Industrial Hygienists, the AmericanAcademy of Industrial Hygiene, the AmericanBoard of Industrial Hygiene, and the AmericanIndustrial Hygiene Assosiation.

2. The Canons of Ethical Conduct are as follows:Canon 1: Industrial Hygienists shall practice theirprofession following recognized scientific princi-ples with the realization that the lives, health, andwell-being of people may depend upon their pro-fessional judgment and that they are obligated toprotect the health and well-being of people. Canon2: Industrial Hygienists shall counsel affected par-ties factually regarding potential health risks andprecautions necessary to avoid adverse healtheffects. Canon 3: Industrial Hygienists shall keepconfidential personal and business informationobtained during the exercise of industrial hygieneactivities, except when required by law or over-riding health and safety considerations. Canon 4:Industrial Hygienists shall avoid circumstanceswhere a compromise of professional judgment orconflict of interest may arise. Canon 5: IndustrialHygienists shall perform services only in the areas of their competence. Canon 6: Industrial


Hygienists shall act responsibly to uphold theintegrity of the profession.

3. The various environmental factors or stressesthat can cause sickness, impaired health, or sig-nificant discomfort in workers can be classifiedas chemical, physical, biological, or ergonomic.

4. The student should demonstrate an under-standing of what this form is, how it can be con-sulted for toxicological information, and whomight find the information useful.

5. The student should demonstrate an under-standing of the various routes of entry for harm-ful agents: inhalation, skin absorption, andingestion.

Chapter 2 The LungsANSWERS—Quiz 1

1. b

2. a

3. b

4. a

5. b

6. c

7. a

8. c

9. b

10. a

11. The human respiratory system includes the nose,the pharynx, the larynx, the trachea, the bronchi,and the lungs.

12. Sounds are created as air is forced past the vocalcords, making them vibrate. These vibrations makethe sound. Words and other understandable


4

sounds are formed by the tongue and muscles ofthe mouth.

13. The trachea divides into the right and left mainstem bronchi.

14. Metabolism is the process through which the bodycombines oxygen with food substances and thusproduces energy.

15. The AMA Guides classify respiratory impairmentinto four classes: none, mild, moderate, and severe.

16. Bronchitis is an inflammation of the lining of thebronchial tubes.

17. In a relaxed state, a person breathes in and out10-14 times a minute, with each breath lasting 4-6 seconds.

18. A pneumothorax is an introduction of airbetween the pleural layers that would decreaseor disrupt the negative atmospheric pressurebetween the layers; the lung would partially ortotally collapse.

19. Carbon dioxide diffuses from tissue cells and tissue fluid into the blood because the concentra-tion of carbon dioxide in tissue cells and fluid ishigher than in the blood in capillaries. If there is apressure difference across a permeable membrane(such as that separating the alveoli from the pul-monary capillaries), gas molecules pass from thehigh- to low-pressure region until the pressures areequalized.

20. The nose is an external organ lined by an exten-sive mucous membrane that warms, moistens,and filters inhaled air. It is the organ of smell.

ANSWERS—Quiz 2

1. a

2. b

3. a

4. b

5. a

6. d


7. b

8. d

9. b

10. The two passageways at the bottom of the throatare the esophagus and the trachea.

11. Cilia are hairlike filaments in the nasal cavity andnasopharynx that move in coordinated waves topropel mucus and trapped particles toward thenostrils.

12. The right lung is partially divided into threelobes; the left lung is divided into only two lobes.

13. Two diseases associated with an obstructive ventilatory defect are asthma and chronicobstructive pulmonary disease (COPD).

14. Fine aerosols are potentially more harmful thanlarger aerosols because only the small (fine) par-ticles are likely to reach the alveoli in great quan-tities, and because the alveoli are the mostimportant area in the lungs.

15. Particles deposited in the alveoli will be engulfedby macrophages that migrate proximally to theairways and are either expectorated or swal-lowed or may enter the interstitial tissue.

16. The classification of respiratory impairment is based primarily on spirometric tests of pul-monary function and gas diffusion studies.

17. Vital lung capacity is measured by inhaling asdeeply as possible and blowing out as much aspossible into a spirometer.

18. Two common forms of pneumoconiosis are sil-icosis and asbestosis.

19. In diseases associated with an obstructive ven-tilatory defect, there is reduction of airflow ratesand prolongation of expiration. In diseases caus-ing a restrictive ventilatory defect, there is adecreased ability to take a deep breath due toscarred lungs.

20. The three general categories of inhaled contam-inants are as follows: (1) aerosols and dusts,which, when deposited in the lungs, may

produce tissue reaction and/or disease; (2) toxicgases, which may produce direct tissue injury;and (3) toxic aerosols, which do not affect thelung tissue but are passed from the lung into thebloodstream, where they are carried to otherorgans or have adverse effects on the oxygen-carrying capacity of the bloodstream.


1. The inhalation of sufficient quantities of dust,regardless of its chemical composition, can causea person to choke or cough; it can also accumu-late in the lungs. Depending on its chemical composition, dust can cause an allergic or sensitization reaction in the respiratory tract.Depending on both its size and chemical composition, dust can, by physical irritation orchemical action, damage the airway and/or lung.

2. Given adequate recovery time—about 16 hours—after an eight-hour exposure to dust, the healthylung can cleanse itself.

3. Procedures useful in evaluating impairment ofthe respiratory system include but are not lim-ited to (1) complete history and physical exam-ination with special reference to cardio-pulmonary systems and signs; (2) chestroentgenography (posteroanterior, PA) in fullinspiration, lateral, and other procedures as indi-cated; (3) hematocrit or hemoglobin determi-nation; (4) electrocardiogram, FEV1, FVC, andDco; and (5) other tests, such as blood gas andpulmonary exercise studies.

Chapter 3The Skin and OccupationalDermatosesANSWERS—Quiz 1

1. b

2. b

3. a

4. a

2 • The Lungs

5©2002 National Safety Council

5. b

6. c

7. d

8. a

9. b

10. b

11. d

12. They remove the skin’s surface lipids and dis-turb the keratin layer of cells so that cells losetheir water-holding capacity.

13. Hair follicles and sweat glands serve as routesfor the percutaneous absorption of such drugsas nicotine, nitroglycerine, estrogen, and scopo-lamine.

14. Nonimmunologic contact urticaria is the mostcommon type of contact urticaria.

15. The skin’s two lines of defense against sunlightare an increase in pigmentation and a thicken-ing of the stratum corneum.

16. A hydrofluoric acid burn is characterized byintense pain that is often delayed and progres-sive deep tissue destruction (necrosis).

17. Temperatures higher than room temperaturedecrease the breakthrough time of chemicals.

18. Categories of glove standards depend on thetype of glove material used, the type of workbeing done, and the type of hazard encountered.

19. The incidence of allergic contact dermatitisdepends on several factors, such as the natureof the materials handled, predisposing factors,and the ability of the physician to accurately useand interpret patch tests. While an irritant usu-ally affects many workers, a sensitizer generallyaffects few workers. Exceptions to this ruleinclude potent sensitizers, such as poison oakoleoresin, or epoxy resin and components.

20. Patch tests are designed to tell whether peoplewho have previously worked on similar jobs are

sensitized to the chemicals with which they haveworked. The tests cannot predict whether newworkers will become sensitive to certain mate-rials and develop dermatitis. Unless there isactive skin disease at the time of placement, med-ical staff must be careful about restricting peo-ple who are not specifically sensitive to the agentsinvolved in a job just because of a history of skinproblems. In many cases, the medical staff is lim-ited to informing the individual of the risk. Safetyand human resources departments as well asindustrial hygienists, supervisors, and othersmay also play a role in recommending suitableplacement on the basis of patch test findings.

ANSWERS—Quiz 2

1. a

2. b

3. b

4. a

5. a

6. d

7. b

8. b

9. a

10. c

11. a

12. Body heat is lost when sweat evaporates.

13. Most of the causes of occupational skin diseasecan be classified as chemical, mechanical, phys-ical, biological, or botanical.

14. Phototoxicity and photoallergy are the two typesof photosensitivity that are generally recognized.

15. The two main types of glands found in the der-mis are sweat glands and sebaceous, or oil, glands.

16. The primary function of environmental controlmeasures in preventing occupational dermatitis



is to reduce the possibility of contact with anoffending agent.

17. Four important chemical parameters that shouldbe considered when evaluating glove perform-ance are resistance to swelling, degradation, per-meation, and penetration.

18. Clothing worn on the job should not be worn athome because workers’ families can developevarious types of dermatoses from contact withcontaminated clothing. Also, if work clothes arelaundered at home, workers’ other clothes maybecome contaminated.

19. One complication of extensive burns is infection,which can endanger the life of the burn victim.In fact, infection is the source of most burn com-plications. Extensive burns can also result in aloss of body fluid, either plasma or lymph fromthe blood, that can then cause the victim to gointo shock. Finally, the functional, cosmetic, andpsychological complications of extensive burnsmay require the attention of a rehabilitation team.

20. The classifications for the dermatologic reactionsto gloves include irritation from occlusion, fric-tion, and maceration, as well as allergy to glovematerials and their chemical additives. In thiscase, wearing gloves can lead to allergic contactdermatitis or allergy to certain natural rubberlatex proteins causing contact urticaria. The clas-sifications also cover aggravation of preexistingskin diseases and penetration of chemicalsthrough gloves. Infrequent reactions to endo-toxins and ethylene oxide, and to depigmentingchemical constituents of gloves have also beenreported.


1. In addition to more direct contributors, such asthe duration and extent of exposure to an agent,indirect, or predisposing factors, could be con-tributing to increased incidence of skin diseaseat Healthy Meals. For example, younger, inex-perienced workers, such as those hired byHealthy Meals, as well as inadequately trainedworkers, have a higher prevalence of occupa-tional skin disease than older workers. Skin typealso plays a role. Workers with naturally dry skincannot tolerate the action of solvents and deter-gents as well as persons with oily skin. Folli-

culitis and acne induced by cutting oils are com-mon problems for workers with hairy arms andlegs. In warm climates, such as that of Florida,occupational skin disease is more common.Workers in these climates wear less clothing andare more likely to come in contact with externalirritants. They are also less likely to wear pro-tective clothing if the work area is hot. Excessiveperspiration, with resulting skin damage, is morecommon in warm weather along with exposureto sunlight, poisonous plants, and insects, theeffects of which may or may not be job-related.Increased sweating, or hyperhidrosis, can be apredisposing factor in warm or cold climates. Itcan lead to maceration with softening and result-ant separation of skin already irritated by rub-bing in adjacent body areas, as happens in thearmpit and the groin. Consequently, the skin ispredisposed to fungal and bacterial infections.Caustics, soda ash, and slaked lime among othermaterials become irritants in solution; however,sweating can protect an individual by dilutingtoxic substances. Gender, hereditary allergy oratopy, personal hygiene, and preexisting skindisease are also predisposing factors.

2. Miliaria, also known as prickly heat or heat rash,is an occupational skin disease related to heatand sweat. It is an inflammatory reaction toretained extravasated sweat that can occur whensweat ducts are obstructed. The lesions may bepinpoint to pinhead-sized papules and vesicles,or blisters, on the chest, back, and submammary,inguinal, and axillary folds. People who sweatprofusely while exposed to heat commonly reactby developing miliaria. The hot, humid condi-tions in which employees at Healthy Meals workcould have led to miliaria.

3. Food processing, such as that done by HealthyMeals, is among the most hazardous industrialprocesses for skin disorders. The others include:the use of cutting oils and coolants in machinetool operation, plastics and rubber manufactur-ing, leather tanning and finishing, metal platingand cleaning, construction, printing, forest prod-ucts manufacturing, and agriculture. In 1997 theincidence of occupational skin disease in the agri-cultural sector was 226 cases per 100,000 full-time workers per year, the highest of allindustries. Agriculture was followed by manu-facturing, which registered 139 cases per 100,000full-time workers, and services, which registered

3 • The Skin and Occupational Dermatoses


61 cases. The transportation/utilities and min-ing industries had similar rates of incidence, 52and 51 respectively. Construction and whole-sale/retail trade were at the end of the list.

Chapter 4The EarsANSWERS—Quiz 1

1. a

2. a

3. b

4. a

5. b

6. a

7. a

8. a

9. b

10. c

11. b

12. c

13. b

14. Student may provide either the technical or col-loquial names for the bones of the ossicular chain.They are the hammer (malleus), anvil (incus),and stirrups (stapes).

15. The ear canal is prone to infection (otitis externa)because of its high skin temperature and humid-ity. Bacterial and fungal infections occur morereadily under circumstances of heavy perspira-tion or head immersion. Swimmer’s ear and der-matitis are common ear canal problems.

16. If a live insect enters the ear canal, drop lightmineral oil into the canal to suffocate and quiet

the insect until it can be removed by a doctor.

17. Cotton-tipped swabs tend to pack wax into theear canal, and swabbing stimulates excess pro-duction of wax. Normally, the ear canals are self-cleaning.

18. Perforation or rupture of the tympanic mem-brane can be caused by infection, direct injury(e.g., from a penetrating object) or sudden pres-sure changes (barotrauma). Examples of the lat-ter would be a blow to the side of the head orlarge pressure changes associated with air flight,underwater diving, or explosions. Most perfo-rations heal spontaneously and do not requiresurgical repair, except for those caused by hotsubstances such as welding splatter.

19. Allergic and infectious conditions that affect thenose and throat can cause swelling, adhesions,or masses in the Eustachian tubes. Failure of theEustachian tube to ventilate creates a vacuum inthe middle ear space, which in turn causes oneof two pathological events to occur: It pulls fluidinto the middle ear, resulting in a condition callednonsuppurative otitis media, or it pulls theeardrum inward.

20. Disease of the middle ear ossicles can impairhearing in two ways: fixation (the bony chaincannot vibrate or vibrates inefficiently) and inter-ruption (a gap in the chain).

21. An individual should be referred to a physi-cian for further medical evaluation when he orshe experiences ear pain; drainage; dizziness;severe persistent tinnitus; sudden, rapidly pro-gressive of fluctuating hearing loss; a feelingof fullness or discomfort in the ear; excessivecerumen accumulation or a foreign body in theear canal; change of the baseline audiogram ofmore than 15 dBH; difference in hearing levelsof the ears of more than 15 dB at 500, 1,000, and2,000 Hz or more than 30 dB at 3,000, 4,000, and6,000 Hz; or average hearing level at 500, 1,000,2,000, and 3,000 Hz is greater than 25 dB ineither ear.

22. Wave motions in the air set up sympathetic vibra-tions that are transmitted by the eardrum andthe three bones in the middle ear to the fluid-filled chamber of the inner ear. In the process,the vibrations of the eardrum are converted to



much smaller but more powerful mechanicalvibrations by the ossicles, and finally into fluidvibrations. The wave motion in the fluid is sensedby the nerves of the cochlea, which transmit neu-ral messages to the brain.

ANSWERS—Quiz 2

1. b

2. a

3. b

4. b

5. a

6. b

7. b

8. c

9. c

10. d

11. c

12. d

13. An abnormal narrowing of the ear canal is calledstenosis and may be caused by congenital mal-formation, bony growth (exostosis), or infection.

14. A variety of ailments can affect the inner ear. Forexample, damage can result from congenital/developmental defects, systemic diseases (mul-tiple sclerosis, diabetes), infection (mumps orchronic otitis media), exposure to noise or cer-tain toxins (including medications, such as antibi-otics or diuretics), circulatory problems (stroke),and trauma (concussion or skull fracture). In theworkplace, exposure to excessive vibration,heavy metals, organic solvents, and carbonmonoxide may contribute significantly to thehearing loss induced by chronic ambient noiseor other medical problems.

15. Meniere’s disease affects both parts of the innerhear (hearing and balance) and its cause isunknown. It is characterized by episodic

4 • The Ears

9

dizziness, often severe, and associated with nau-sea, vomiting, fluctuating hearing loss that is generally progressive, ringing or hissing noise,and a peculiar sensation of fullness in theinvolved ear.

16. Acoustic neuroma is a tumor that occurs mostcommonly in middle-aged persons and affectsthe eighth cranial nerve. Although not malig-nant, it can cause disabling symptoms of bothhearing loss and vestibular dysfunction. Work-ers with vertigo or equilibrium problems maynot be medically fit for safety-sensitive tasks suchas operating motor vehicles or working atheights.

17. Tinnitus is the perception of sound arising in thehead. It may be heard only by the affected per-son (subjective tinnitus) or it may be audible tothe examiner also (objective tinnitus). Objectivetinnitus is usually a symptom not of disease ofthe ear but of a tumor or vascular malformation.

18. Audiometric results are recorded on a standardchart called an audiogram. It is a frequency-by-intensity graph on which a person’s hearingthreshold for pure tones is plotted.

19. The factors that determine the duration andseverity of noise-induced hearing loss includesound level, frequency distribution of sound,duration of sound, temporal distribution ofsound exposure, type of sound energy, individ-ual differences in tolerance of sound.

20. Research on other effects of noise indicates thatit may cause interference with communication,altered performance, annoyance, and physio-logical responses such as elevated blood pres-sure and sleep disturbances. Shouting toovercome noise has been observed to lead tochronic laryngitis and vocal cord polyps.

21. When testing hearing by air conduction, head-phones are placed over the ears of the test sub-ject. A pure tone signal from the audiometer ispresented through the headphones and travelsthrough the ear canal, the middle ear, and intothe inner ear, thus allowing evaluation of theentire hearing mechanism, both conductive andsensorineural. Bone conduction audiometry eval-uates only the sensorineural hearing mechanism.A bone vibrator is placed on the mastoid bone


behind the outer ear. This sends vibrationsdirectly through the skull bones to the cochleain the inner ear, bypassing the conductive path-way of the outer and middle ear. Bone conduc-tion testing is considered a diagnostic test andis not performed as part of routine industrialhearing assessments.


1. The student should demonstrate an under-standing of the various causes of hearing loss,paying particular attention to Mr. Sachdev’s age,occupation, and the fact that he wears earplugswhich may push wax deeper into his ear. Theanswer might include, but is not limited to, thefollowing: Physical blockage of auditory canals,congenital/developmental defects, infection,exposure to noise or certain toxins, circulatoryproblems, trauma, exposure to vibration, heavymetals, organic solvents, and carbon monoxide,traumatic damage such as punctured eardrums,drug-induced damage, etc.

2. When testing hearing by air conduction, head-phones are placed over the ears of the test sub-ject. A pure tone signal from the audiometer ispresented through the headphones and travelsthrough the ear canal, the middle ear, and intothe inner ear, thus allowing evaluation of theentire hearing mechanism. Bone conductionaudiometry evaluates only the sensorineuralhearing mechanism. A bone vibrator is placedon the mastoid bone behind the outer ear. Thissends vibrations directly through the skull bonesto the cochlea in the inner ear, bypassing the con-ductive pathway of the outer and middle ear.Bone conduction testing is considered a diag-nostic test and is not performed as part of rou-tine hearing assessments, so you will use an airconduction test on Mr. Sachdev.

3. The factors that determine the duration andseverity of noise-induced hearing loss includesound level, frequency distribution of sound,duration of sound, temporal distribution ofsound exposure, type of sound energy, and indi-vidual differences in tolerance of sound.

4. The student should give an adequate descrip-tion of the hearing process, along the lines of the following: The outer ear funnels and conducts sound vibrations to the eardrum


10

through the ear canal. The eardrum vibrates inresponse to the sound waves that strike it. Thisvibratory movement is transmitted to the chainof three tiny bones in the middle ear. Thesesmall bones, the ossicles, conduct the soundvibration across the air-filled middle ear cav-ity to a fluid in the inner ear. The vibration ofthe ossicles creates waves in the inner ear fluidthat stimulate microscopic hair cells. The stim-ulation of these hair cells generates nerveimpulses, which pass along the auditory nerveto the brain for interpretation.

Chapter 5The EyesANSWERS—Quiz 1

1. b

2. a

3. b

4. a

5. b

6. a

7. b

8. a

9. d

10. a

11. d

12. b

13. c

14. The three layers of tissue surrounding the inter-nal structures of the eyeball are the externalfibrous layer, a middle vascular layer, and aninner layer of nerve tissue.

15. The tarsal glands, located in the eyelids, secrete


an oil to lubricate the surfaces of the eyeball andeyelids.

16. The choroid is a darkly pigmented layer of tis-sue underlying the retina, which contains anextremely rich blood supply that is believed todissipate the heat resulting from absorbed lightenergy.

17. The ciliary muscles alter the lens shape to fine-focus the incoming light beam.

18. The two functionally discrete types of light-sen-sitive cells in the retina are rods and cones.

19. An ophthalmologist is a doctor of medicine whospecializes in the comprehensive care of the eyeand visual system and is licensed by a state topractice medicine and surgery.

20. A phoropter is used to determine refractive cor-rection (eyeglass prescription) and binocularvision abnormalities. It consists of test lenses andprisms that are added and removed using bothobjective criteria and subjective responses.

21. Stereoscopic vision gives a perception of depth.There is a slight difference in the images on thetwo retinas; there is a right-eyed picture on theright retina and a left-eyed picture on the leftretina. The two images blend in consciousnessand give an impression of depth or solidity.

22. Astigmatism occurs when the curvature of thecornea is irregular so that some rays of light arebent more in one direction than in another; theresulting image is blurred because if one part ofthe ray is focused, the other part is not.

ANSWERS—Quiz 2

1. a

2. b

3. a

4. a

5. b

6. c7. a

5 • The Eyes

11

8. d

9. a

10. Significant impairment of vision that cannot beimproved by corrective lenses is designated as“low vision.”

11. The leading causes of existing cases of blindnessare (1) glaucoma, (2) macular degeneration, (3)cataracts, (4) atrophy of the optic nerve, (5) dia-betic retinopathy, and (6) retinitis pigmentosa.

12. A diopter is a unit of measurement of the refrac-tive or light-bending power of a lens.

13. Rod monochromatism is a condition in which peo-ple have no cones in their retinas, only rods.These people are truly color blind.

14. Viral eye infections usually produce tearing; bac-terial infections cause pus or mucous discharge;and allergic reactions cause itching and occa-sionally a “stringy” discharge.

15. Cataracts can be associated with industrial expo-sures to ionizing radiation, ultraviolet radiation,infrared radiation, foreign bodies, and certainchemicals.

16. Nystagmus is the involuntary movement of theeyeballs.

17. Acute keratoconjunctivitis, an acute inflammationof the cornea and conjunctiva, is commonlyknown as welder’s flash.

18. Only safety eyewear that meets or exceeds the requirements of ANSI standard Z87.1B1989is approved for full-time use by industrial workers.

19. For safety eyewear, polycarbonate lenses are themost impact-resistant.

20. About 4 percent of the population (95 percent ofwhom are male) inherits a defect in one of thecone pigments so that the wavelength of maxi-mum absorption is somewhat shifted. Peoplewith these color defects are not color “blind,” asthey do see colors, but rather are color defectivein that they perceive certain colors differently


from people with normal cone pigments.

21. An eye-hazard area is an area where the contin-uous or intermittent work being performed cancause an eye injury to anyone in the area. Theconcept emphasizes the need for process andenvironmental controls such as enclosures andradiation-absorbing surfaces, and provides eyeprotection equipment for workers, neighboringworkers, supervisors, and visitors.


1. Invasion by a foreign body is the most commontype of physical injury to the eye.

2. The most common complication with an indus-trial eye injury is infection, which can causedelayed healing and corneal scarring.

3. In some cases, the speed of small metallic particles creates enough heat to sterilize them,making infection less of a problem. Wood parti-cles, however, do not heat up; if they penetratethe eye, they can cause dangerous infection,which usually causes a marked reduction invision.

Chapter 6Industrial ToxicologyANSWERS—Quiz 1

1. b

2. b

3. b

4. a

5. a

6. b

7. d

8. d

9. c

10. c

11. d

12. The cutaneous absorption rate of some organicchemicals increases when temperature and per-spiration increase.

13. The dose-response relationship can be expressedas the product of concentration (C) and durationof exposure (T).

14. Hypersusceptibility is the occurrence of the usualhealth effects caused by a substance followingexposure to air levels below those associatedwith effects for most individuals.

15. According to NIOSH, a substance should be con-sidered a suspected carinogen if it produces can-cers in two or more animal species.

16. If epidemiological data and cases of human expo-sure are not available for study, the preferredmethod for determining TLVs® is to use studiesof long-term inhalation tests involving severalanimal species at concentrations both above andbelow the lowest effect level.

17. Rates of absorption, metabolism, and excretiondetermine when it is most appropriate to ana-lyze biological samples in relation to durationand time of exposure.

18. Samples of urine, blood, or expired air takenunder strictly defined conditions are used todetermine Biological Exposure Indices®.

19. Toxicologists define toxicity as the ability of asubstance to produce an unwanted effect whenthe substance has reached a sufficient concen-tration at a certain site in the body. They definehazard as the probability that this concentrationwill occur at that site. Toxicity, along with thechemical and physical properties of a substance,determine the level or degree of hazard.

20. A mutagen is an agent that affects the geneticmaterial of an exposed organism. It may causecancer, birth defects, or other undesirable effectsin later generations. People working with a certain chemical may not be harmed, but theiroffspring can be. A teratogen, however, affectsonly the developing fetus. It may be a biologi-



cal, chemical, or physical agent that produces malformations of the fetus without affecting themother or killing the fetus. This is known as ter-atogenesis. Unlike the effects of mutagens, themalformations caused by teratogens are nothereditary. Like mutagens, it is difficult to estab-lish specific cause-and-effect relationshipsbetween teratogens and the birth defects theycan produce.

ANSWERS—Quiz 2

1. a

2. a

3. a

4. b

5. b

6. d

7. c

8. b

9. a

10. b

11. d

12. The toxicity of a chemical depends on the degreeof exposure and absorption.

13. If the skin comes in contact with a toxic sub-stance, either (1) the skin will act as an effectivebarrier, (2) the substance will react with the skinand cause local irritation or tissue destruction,(3) the substance will produce skin sensitization,or (4) the substance will penetrate the skin toreach the blood vessels under the skin and enterthe bloodstream.

14. It is difficult because the lag time between exposure and effect is so severe. Damage causedby mutagens may not show up until the next generation of the exposed organism at the earli-est, and may not appear for several generations.

15. The “Hazcom” or “right-to-know” regulation is

Hazard Communication Standard, 29 CFR1910.1200, which was enacted by OSHA in 1983to set standards for worker notification and train-ing for chemicals in the workplace.

16. When two or more hazardous substances thatact on the same body organ system are present,primary consideration should be given to theircombined effect.

17. If inhaled gases are fat-soluble and are not metab-olized, they are cleared from the body primarilythrough the respiratory system.

18. No, the company can withhold the names of theingredients, but it must disclose their hazardousproperties, if any exist.

19. LD50 is the dose of a substance that is expectedto kill 50 percent of a defined experimental ani-mal population, as determined from exposureto the substance by any route other than inhala-tion. Although LD50 is the concentration that killshalf of the exposed animals, it does not mean theother half are in good health. Generally, LD50units represent the weight of the substance perkilogram of animal body weight, usually mil-ligrams per kilogram. The value should indicatethe species of animal used, the route of admin-istration of the substance, the vehicle used to dis-solve or suspend the substance, if applicable,and the time period during which the animalswere dosed and observed. LD0 is the concentra-tion that produces no deaths in an experimentalgroup and is the highest concentration toleratedin animals. It is rarely used. LD100 is the lowestconcentration that kills 100 percent of the exposedanimals.

20. A substance-specific standard covers the expo-sure limit of the substance that has been deter-mined to provide a safe, healthful workenvironment. It identifies the methods for col-lecting, sampling, and analyzing the substanceand the engineering controls necessary for main-taining a safe environment. The standard shouldsuggest appropriate equipment and clothing forsafe handling of the substance and emergencyprocedures in case of an accident. It should alsospell out the medical surveillance proceduresrequired to detect illness or injury from overex-posure and the signs and labels needed to iden-tify hazardous substances.

6 • Industrial Toxicology



1. TLVs®, or threshold limit values, were devel-oped by the American Conference of Govern-mental Industrial Hygienists (ACGIH) and arethe most widely followed voluntary guides forexposure to airborne contaminants. However,they are not the recommendations of a govern-ment agency and, like standards and guidelinesdeveloped by OSHA, ACGIH, NIOSH, and oth-ers, TLVs® do have drawbacks. Most impor-tantly, they can only serve as guides—not as finelines between safe and dangerous concentrationsof contaminants. Another drawback relates tothe difficulty involved with collecting a trulyrepresentative breathing zone sample. There arealso questions about the extent of absorption ofthe amount inhaled, as well as problems sam-pling the air conditions surrounding nonroutineor nonrepetitive work. Under these workingconditions, air samples can characterize workoperations only on the day the sample is taken.Other drawbacks are the variations in particlesize, absorption, and particle solubility. A finaldisadvantage is that air samples can be acci-dentally or deliberately contaminated.

2. Biological sampling can be a useful way of assess-ing a worker’s exposure to harmful chemicals;however, it should not be substituted for air sam-pling. Biological sampling measures the amountof chemical absorbed via any route (lungs, skin,mucosa, etc.), as well as the effects of addedstress. For example, an increased work load mayresult in a higher respiration rate and a higherintake of a contaminant. Biological samplingshows the total exposure—both on and off thejob—to harmful chemicals. Ethical considera-tions prohibit using workers as “integrated air-sampling devices.”

3. Nearly every tissue on the body can be sampledand analyzed, providing an indication of thebody burden of a substance, the amount of thesubstance circulating in the blood, or the amountbeing excreted. Most biological testing is limitedto urine or blood sampling, but sometimes sam-ples of hair, nails, feces, or other tissues may beuseful. In the case of carbon monoxide and manysolvents, analyzing samples of exhaled breathindicates the level of exposure. Analyses of bio-logical samples can include sampling body flu-ids and tissues and testing them for unchanged


14

substances, such as lead, arsenic, or mercury. Inother cases, analyses of body fluids or tissuescan target the metabolites of the substance.Another type of analysis involves studying vari-ations in the levels of naturally occurringenzymes or other biochemical substances nor-mally present in body fluids or tissues.

Chapter 7 Gases, Vapors, and SolventsANSWERS—Quiz 1

1. b

2. b

3. a

4. b

5. b

6. a

7. b

8. a

9. a

10. b

11. a

12. d

13. The three fundamental states of matter are gases,liquids, and solids.

14. The most commonly used guidelines in theUnited States are TLVs® (Threshold Limit Val-ues), PELs (Permissible Exposure Limits), andRELs (Recommended Exposure Limits.)

15. A functional group in an organic molecule is aregion where reactions can take place.

16. The student needs to name ONE of the follow-ing: Hawley’s Condensed Chemical Dictionary; The


Merck Index; Clinical Toxicology of Commercial Prod-ucts; or Fire Hazard Properties of Flammable Liq-uids, Gases, and Vapors.

17. Cryogenic liquids pose several safety concernsin addition to frostbite from extreme cold. Spillsrapidly vaporize, producing a gas that is initiallysignificantly more dense than air, resulting inpotential oxygen deficiency hazards in pits,vaults, and enclosed spaces. Liquid nitrogen isthe most common cryogenic fluid.

18. For each flammable liquid or gas, there is a min-imum concentration of its vapor in air belowwhich propagation of flame does not occur oncontact with a source of ignition because the mix-ture is too lean. There is also a maximum con-centration of vapor, in air, above whichpropagation of flame does not occur because themixture is too rich. This is its flammable range.

19. A simple asphyxiant exerts no direct action, butacts passively by merely replacing oxygen in theair so that the concentration of oxygen falls belowthe 18 percent minimum required for life. Chem-ical asphyxiants react with essential cellular mol-ecules to disrupt the transport or use of oxygen.Chemical asphyxiants may also interfere with thecell’s ability to use the oxygen which is delivered.

20. The evaluation procedure, where the industrialhygienist assesses the degree of risk in the work-place, is based on the following factors: the tox-icity of the substance, the concentration in thebreathing zone, the manner of use, the length oftime of the exposure, the controls already in placeand their effectiveness, and any special suscep-tibilities of the employees.

21. Where a solvent system is in use, three distinctpossible routes of exposure must be considered.First, if an opportunity exists for skin contact,dermal absorption is important. If the vapor pres-sure is high, or the temperature is high, inhala-tion of vapors is important. Finally, one mustalso consider the possibility of exposure to anaerosolized mist of the solution, in which casethere is also exposure to the solutes. Because ofthe high volume of breathing and the large sur-face area of the lungs, which are designed formaximum interchange between blood and airin the lungs, inhalation is usually the most impor-tant route of exposure.

7 • Gases, Vapors, and Solvents

15

ANSWERS—Quiz 2

1. b

2. b

3. a

4. b

5. a

6. a

7. b

8. c

9. c

10. b

11. b

12. a

13. d

14. NTP stands for normal temperature (25 C) andpressure (1 atmosphere).

15. Threshold Limit Values refer to airborne con-centrations of substances and represent condi-tions under which it is believed that nearly allworkers may be repeatedly exposed day afterday without adverse health effects.

16. HF is particularly corrosive to tissue and bone.Pain from a solution stronger than 50 percent isfelt within minutes; lower concentrations maynot produce pain for hours. Serious tissue dam-age may result without the person being awareof it. HF burns require immediate action: irri-gate the exposed area to flush away as much HFas possible and seek medical attention immedi-ately. Treatment is dependent on the severity ofthe burns. Mild cases can be managed with mag-nesium oxide but more severe burns may requireinfiltration of the affected tissue with calciumgluconate.

17. The common organic solvents can be classifiedas aliphatic, cyclic, aromatic, halogenated hydro-


carbons, ketones, esters, alcohols, and ethers.

18. The halogens are a group of five elements: fluorine, chlorine, bromine, iodine, and astatine.

19. Methanol and ethanol are the two most impor-tant industrial alcohols. Methanol causes sev-eral types of injuries, notably impairment ofvision and injury of the optic nerve. Ethanol isquickly metabolized in the body and largely con-verted to carbon dioxide, and is the least toxicof the alcohols. The undesirable effects of ethanolprimarily are related to its recreational use, as itacts as a depressant, slowing down the centralnervous system.

20. Carbon dioxide, the product of combustion of carbon-based fuels, contributes to the greenhouse effect. Put simply, solar radiationpenetrates the atmosphere and is absorbed by the earth; a portion is radiated back into space,and a portion is consumed in life processes and atmospheric chemical reactions, thus set-ting up a thermal equilibrium. Carbon dioxideabsorbs the shorter wavelength energy re-radiated into space; this energy is manifestedas heat.

21. In the essay, the student should demonstrate acomplete understanding of the dangers posedby organic solvents and solvent vapors, touch-ing upon skin irritations; defatting of the skin;dermatitis; and damage to the liver, kidneys, central nervous system, and peripheral nervoussystem. The student may mention specific symp-toms such as dizziness, disorientation, confu-sion, euphoria, giddiness, paralysis, convulsions,and cardiac arrest.


1. Hydrocarbons are those compounds with onlycarbon and hydrogen atoms.

2. Different classes include: aliphatic hydro-carbons, cyclic hydrocarbons, aromatic hydro-carbons, halogenated hydrocarbons, and nitrohydrocarbons.

3. For credit, students should list at least two sources for hydrocarbons. These include:


16

volcanoes, biological decay, biological activityin soils and the oceans, forest or grassland fires,automobiles, and solvents from industrial cleaning and surface-coating processes.

4. In the presence of sunlight, hydrocarbons reactwith atomic oxygen and ozone to produce alde-hydes, acids, oxides of nitrogen and sulfur, anda series of other noxious compounds to form airpollution. The student should provide an answerthat discusses the physical effects of air pollu-tion on the human body.

5. In 1987, the industrialized nations met and signedthe Montreal Protocol on Substances that Depletethe Ozone Layer. The Montreal Protocol calls forthe reduction of use and elimination of the majorozone-depleting chemicals.

6. Should the destruction of ozone by fluorocar-bons and other materials prove to be significant,the amount of solar ultraviolet radiation reach-ing the earth’s surface will increase. This wouldimpair agricultural production and increase theincidence of skin cancer.

7. Carbon dioxide contributes to the greenhouseeffect. Put simply, solar radiation penetrates theatmosphere and is absorbed by the earth; a portion is radiated back into space, and a portion is consumed in life processes and atmos-pheric chemical reactions, thus setting up a thermal equilibrium. Carbon dioxide absorbsthe shorter wavelength energy re-radiated intospace; this energy is then manifested as heat. Ithas been estimated that an increase of CO2concentration to 370 ppm from the present valueof about 320 ppm would increase the tempera-ture 0.5 C.

8. You should not use respirators as the primaryor only means of protection against hazardouschemical vapors because too many factors limittheir use. They can be used as emergency orbackup protection. Respiratory equipment is lim-ited by leakage around the mask edges, surfacecontamination, impaired efficiency with use, andneed for adequate oxygen. Unless it is correctlyused and properly cared for, a respirator maypresent a greater danger to a person than no pro-tection at all.


Chapter 8ParticulatesANSWERS—Quiz 1

1. a

2. b

3. a

4. b

5. b

6. a

7. a

8. b

9. b

10. b

11. In the field of industrial hygiene, particulate mat-ter is defined as small (less than 100 microme-ters in diameter) pieces of solid materials, liquiddroplets, or microbiological organisms.

12. Particles smaller than about 0.001 µm start to actlike gases and thus are not treated as particulatematter.

13. The five primary mechanisms of particle depo-sition are (1) inertial impaction, (2) interception,(3) sedimentation (settling), (4) electrostatic attrac-tion, and (5) diffusion (Brownian movement).

14. Because long, narrow asbestos fibers can travelthrough the lung lengthwise, like an arrow, theycan penetrate much deeper into the lung than anonfibrous particle with a diameter equal to thelength of the fiber. As a result, asbestos fibers canmake it to the alveolar region of the lungs, whichresults in scarring of the lungs and cancer.

15. Industrial hygienists are concerned with theequivalent aerodynamic diameter (EAD) of a

8 • Particulates

17

particle rather than its actual diameter.

16. Types of particle sampling that are common inindustrial hygiene include air sampling, surfacesampling, biological monitoring, and bioassays.

17. Surface sampling is conducted for several reasons:(1) surface sampling is used to determine adequacy

of housekeeping and engineering controls in minimizing the spread of highly toxic PM

(2) when working on laboratory fume hoods, itis used to verify that no potentially explo-sive perchlorate residue is present in thehood, plenum, duct, or fan

(3) prior to releasing excess equipment for reuse,utilization, sale, or donation, it is appropri-ate to test for contamination

(4) when it is necessary to determine what met-als are/were used in an area, surface sam-ples can be analyzed for many metals byinductive coupled plasma emission spec-troscopy or similar tool

(5) surface sampling can be used where the con-taminant has a high percutaneous toxicity

(6) it can be used where the surface dust is amajor component of the source term for air-borne exposure

(7) following certain types of abatement actions(lead in particular), surface sampling can beused to verify the adequacy of the decontam-ination and contamination control procedures

(8) surface sampling can be used wheneverworking with potentially radioactive PM

18. The inaccuracy of optical methods of asbestosanalysis arises from the fact that the analystcounts all fibers that meet the method specifi-cations, not just asbestos fibers. In addition, thelimited resolution of optical microscopes meansthat the narrowest and potentially most toxico-logically significant fibers are systematicallyundercounted.

19. The most common method for differential fibercounting in asbestos sampling is transmissionelectron microscopy (TEM).

20. The aerosol is passed continuously through thedevice, illuminated by a light, and the scatter-ing of light at a 90-degree angle by particles in


the aerosol is used to enumerate and size theparticles.

21. In most cases, a primary factor in the toxicity ofinhaled radiological materials is the specific activ-ity of the radioactive atom. Species with highspecific activities emit a lot of ionizing radiationper unit of time and mass, and thus more rap-idly affect tissue, causing genetic and somaticcell damage. Also important is the type andenergy of the radioactive particle (or photon)emitted when the atom decays.

22. The airborne limits for radioactive particles aretermed Derived Air Concentrations (DACs).These limits are back-calculated from thepreestablished limit for radiation dose to thelungs and other tissues. Unlike chemical expo-sure limits, which are usually expressed as eight-hour average exposure limits, the DACs areyear-long averages.

ANSWERS—Quiz 2

1. a

2. b

3. a

4. a

5. a

6. d

7. a

8. d

9. a

10. Pneumoconiosis is the accumulation of dust in thelungs and the tissue reaction to its presence.

11. The ceiling limit is a concentration of the chem-ical agent that is usually intended as an absolutelimit, a value never to be exceeded even for ashort time.

12. Fibrosis is a type of scarring of the lung tissue,which results in loss of flexibility, difficultybreathing, and in severe cases, damage to the

right side of the heart as it tries to compensatefor reduced blood oxygenation. Many of thepneumoconioses result in fibrosis.

13. In industrial hygiene there is growing emphasison using particle size-selective sampling to bet-ter characterize the level of exposure to relevantdust rather than total dust.

14. As an improved version of total dust sampling,the ACGIH’s Inhalable Particle Mass procedureis applicable for particles that can cause adversehealth effects regardless of where they depositin the respiratory tract.

15. To evaluate dermal exposure, ultraviolet fluo-rescent powders are added to pesticides or otherchemicals that can then be imaged and recordedphotographically to show the spread of contam-ination and problems with the workers’ practices.

16. Gravimetric analysis is used most often whensampling for nuisance dust or Particulates NotOtherwise Classified (PNOC).

17. Biological organisms most often of interest to thetypical industrial hygienist are limited to bacte-ria, fungi, and viruses.

18. General area samples are used extensively inasbestos abatement, as well as for sampling air-borne bacteria and fungal spores.

19. Radon progeny, or radon daughters, are partic-ulate matter decay products.

20. In many cases multiple exposures do not inter-act, so each exposure is treated independently.Other exposures are known or assumed to beadditive. The more closely the particulate mat-ter-related health effects are, the more appro-priate it is to judge them to be additive. Theexposures are measured simultaneously, theTWA fraction of the respective exposure limitsfor each agent are added together, and if the valueexceeds 1.0, an overexposure situation is assumedto exist. An additive analysis may even includea mixture of PM, vapors, and even physicalagents.

21. When sampling PM in a moving airstream, theairflow in the sampling line must be isokineticwith the airflow in the duct or stack; that is, the



velocity of the air in the duct must be the sameas the velocity of air in the sampling tube. Theeffect of nonisokinetic sampling in a duct orstack can be quite severe. The other potentialproblem is the use of a sampling tube withsharp bends. The sampling tube must facestraight into the airflow and curve slowly toexit from the duct. Any sharp bends will causeparticle accumulation at the bend by inertialimpaction.


1. Dermal monitoring is a type of PM monitoringthat is appropriate for particles presenting a sig-nificant skin absorption hazard, such as pesticides.

2. The pesticides are measured from patches of fab-ric attached to the clothing of workers. After sam-pling, the patches are removed and sent to alaboratory for analysis of the pesticide.

Chapter 9Industrial NoiseANSWERS—Quiz 1

1. a

2. a

3. b

4. a

5. b

6. a

7. b

8. c

9. b

10. d

11. d

12. Occupational hearing loss is a hearing impair-

ment of one or both ears, partial or complete,that results from one’s employment. It can be theresult of acoustic trauma or noise-induced hear-ing loss.

13. The root-mean-square (rms) sound pressure isused to measure the magnitude of a sound wave.Sound pressure is measured in micropascals(µPa), newtons per square meter (N/m2), micro-bars (µbar), and dynes per square centimeter(d/cm2).

14. Changing the frequency of a sound changes itsrelative loudness because the human ear is moresensitive to the higher frequencies of sound.

15. A source measurement reflects the characteris-tics of a particular sound source, while an ambi-ent-noise measurement reflects the characteristicsof a sound field of generally unspecified orunknown sources.

16. The three parts are the source that radiates soundenergy, the path along which the sound energytravels, and the receiver.

17. The four categories of personal hearing-protec-tive devices are enclosures, aural inserts, super-aural protectors, and circumaural protectors.

18. If an employee has experienced a standardthreshold shift (STS), a protective device mustreduce his or her level of noise exposure to 85dBA or below.

19. The noise emitted by a source travels outwardin all directions. If all of the walls, floor, and ceil-ing surrounding the source are hard, reflectingsurfaces, the sound is reflected again and again.The result is a semireverberant location. Almostall industrial machine installations are found insemireverberant locations. Close to a machine,most of the noise is produced by the machine;close to the walls, the reflected noise may be morepowerful. The sound level in semireverberantlocations is equal to the sum of the noise radi-ated directly by the source and the noise reflectedoff the walls, floor, and ceiling. Applying sound-absorption material to the walls and ceiling canreduce reflected noise, but cannot decrease thenoise produced by the source.

20. All job applicants should take preplacement

9 • Industrial Noise


hearing-threshold tests—not just those who maybe assigned to work in noisy areas. These testsare important for two reasons. By screening allapplicants, a company is able to establish a base-line hearing threshold for each employee forcomparison in the future. A company can alsouse the results of preplacement tests to protectitself from liability for preexisting hearing lossincurred elsewhere. If an employee with hear-ing damage is hired and then exposed to haz-ardous noise levels, the company may be liablefor all the employee’s hearing loss unless it canprove that the employee was hired with a pre-existing condition.

ANSWERS—Quiz 2

1. a

2. b

3. b

4. b

5. a

6. c

7. a

8. d

9. c

10. a

11. b

12. The effects include the masking of wantedsounds, particularly speech; auditory fatigue;damage to hearing; and annoyance.

13. The threshold of hearing is the weakest soundthat can be heard by a person with very goodhearing in an extremely quiet location. Thethreshold of hearing for an average person is asound pressure of 20 µPa at a reference tone of1,000 Hz.

14. The upper limit of frequency at which airbornesounds can be heard depends primarily on thecondition of a person’s hearing and the intensity

of the sound.

15. The A-weighted sound level measurement isbelieved to provide a rating of industrial broad-band noises that indicates the harmful effectsthis noise has on human hearing. It has also beenproven to offer reasonably good assessments ofspeech interference and community disturbanceconditions.

16. Earplugs and earmuffs do not reduce or elimi-nate a noise hazard. If these protective devicesfail, the individual wearing them is immediatelyexposed to the hazard.

17. The five components of an effective industrialaudiometric program include medical surveil-lance, qualified personnel, a suitable test envi-ronment, calibrated equipment, and adequaterecord keeping.

18. According to NIOSH, a standard threshold shift(STS) is a 15 dB loss in either ear at frequenciesof 500, 1,000, 2,000, 3,000, 4,000, or 6,000 Hz. Theloss is determined by two consecutive tests.

19. Noise is made up of various sound intensities atvarious frequencies and needs to be broken downinto these frequencies for two reasons. First,people react differently to low-frequency and

high-frequency noises. For example, at the samesound pressure level, high frequency noise ismuch more disturbing and is more likely to resultin hearing loss. Second, the engineering solu-tions for reducing or controlling noise are dif-ferent for low-frequency and high-frequencynoises. Generally, high-frequency noise is easierto control.

20. The company must notify the employee within21 days that he or she was shown to have an STS.The employee must then be fitted with adequatehearing protectors, shown how to use them, andrequired to wear the protectors. Some employ-ees might be referred for further testing if theirtests results are questionable or if they have anear problem of a medical nature caused or aggra-vated by wearing hearing protectors. If subse-quent audiometric tests show that the STSidentified during and earlier test is not persist-ent, the employee can discontinue wearing hear-ing protectors if he or she is exposed to a TWAof less than 90 dBA.




1. Occupational hearing loss is a hearing impair-ment of one or both ears that results from one’semployment. Hearing loss can be partial or com-plete and can result from acoustic trauma or benoise-induced.

2. Acoustic trauma is damage to the sensorineuralareas of the inner ear. It can occur following oneor a few exposures to sudden intense acousticforms of energy resulting from blasts and explo-sions or by direct trauma to the head or ear. Inthe case of acoustic trauma, the worker identi-fies his or her hearing loss with one incident.Unlike acoustic trauma, noise-induced hearingloss is the cumulative permanent loss of hear-ing that develops over months or years of haz-ardous noise exposure. It also damages thesensorineural areas of the inner ear. Noise-induced hearing loss generally affects both earsequally in the extent and degree of loss. To deter-mine if an employee has noise-induced hearingloss caused by conditions on the job, a doctorconsiders: the employee’s history of hearing loss,including onset and progress; the employee’soccupational history, including type of work andyears of employment; the results of theemployee’s otological exam; and the results ofaudiological and hearing studies conducted peri-odically and at preplacement and termination.The doctor must also be able to rule out nonin-dustrial causes.

3. In identifying the risk factors for occupationalhearing loss, it is important to recognize that ifthe ear is subjected to high levels of noise for asufficient period of time, some hearing loss willoccur. The factors that affect the degree andextent of loss include: the intensity of the noise(the sound pressure level), the type of noise (fre-quency spectrum), the period of exposure eachday (worker’s schedule per day), and the totalwork duration (years of employment). Thesefour factors are referred to as noise exposurefactors and are the most important risk factorsfor occupational hearing loss. Other factors thatcan contribute to occupational hearing loss are:individual susceptibility, the age of the worker,coexisting hearing loss and ear disease, the char-acter of the surroundings in which the noise isproduced, the distance fromthe source, and theposition of the ear with respect to sound waves.

4. The risk factors for hearing loss can be aggra-vated by problems with protective equipment,such as earmuffs. When earmuffs are worn witheye protection equipment, the degree of hearingprotection must not be compromised. However,when they are worn over the frames of eye-pro-tective devices, earmuffs are less efficient pro-tection devices. In this case, the amount ofreduction in noise attenuation depends on thetype of glasses being worn as well as the size andshape of the wearer’s head. If a worker mustwear eye protection with earmuffs, devices withcable-type temples are recommended becausethey create the smallest possible opening betweenthe seal of the earmuff and the worker’s head.

Chapter 10Ionizing RadiationANSWERS—Quiz 1

1. a

2. b

3. a

4. b

5. a

6. b

7. a

8. c

9. a

10. b

11. d

12. a

13. c

14. d

15. a

10 • Ionizing Radiation


16. Background radiation is primarily a result of cos-mic rays, which constantly bombard the earthfrom outer space. It also comes from such sourcesas soil and building materials.

17. A film badge is a piece of masked photographicfilm worn as a badge for personal monitoring ofradiation exposure to gamma-, x-, and high-energy beta-radiation. It is darkened by pene-trating radiation, and radiation exposure can bechecked by developing and interpreting the film.The type of masking depends on the type of radi-ation to be measured.

18. Human exposure to neutrons occurs around reac-tors, accelerators, and sources designed to pro-duce neutrons. Determination of the extent ofdamage from neutron exposures must be madeby trained people using special equipment. Theamount of harm caused by a dose is dependentnot only on the number of neutrons absorbedbut also on their energy distribution.

19. The term nuclear radiation describes all formsof radiation energy that originate in the nucleusof a radioactive atom.

20. When a beta-particle is slowed down or stopped,secondary x-radiation, known as bremsstrahlung,may be produced. Light metals such as aluminum are preferred for shielding frombeta-particles because light metals produce lessbremsstrahlung radiation. PlexiglasTM is anothershielding material that is effective.

21. A half-value layer is the thickness of a specifiedsubstance that, when introduced into the pathof a given beam of radiation, reduces the valueof the radiation quantity by one-half. It is some-times expressed in terms of mass per unit area.

22. The effects of irradiation on living systems arestudied by looking for effects on the living cells,changes in biochemical reactions, evidence ofproduction of disease, and changes in life or nor-mal growth patterns.

23. The two types of injurious effects of ionizingradiation are the somatic effects (injury to indi-viduals) and the genetic effects (which are passedon to future generations).

24. All matter is composed of atoms, each of which

has two basic parts: a heavy core, or nucleus, con-taining positively charged particles called pro-tons and neutral particles called neutrons; andrelatively lightweight, negatively charged parti-cles called electrons, which spin around the nuclearcore. Neutrons and protons were once consideredbasic particles. However, they have been foundto be composed of even smaller particles. Theillustration provided by the student should lookcomparable to Figure 10-3, page 262, of the text.

25. X-radiation is commonly thought of as electro-magnetic radiation produced by an x-raymachine. High-speed electrons are suddenlyslowed down when they strike a target, andthey lose energy in the form of x-radiation. Xrays penetrate different materials to varyingdegrees. When the x rays hit the film behindthe object, they expose it just as light would.Since bone, muscle, fat, and other tissues allabsorb x rays in varying degrees, their imageon the film lets you see the distinct structureswithin the body.

ANSWERS—Quiz 2

1. a

2. a

3. a

4. b

5. a

6. a

7. b

8. a

9. a

10. b

11. b

12. c

13. b

14. b



15. d

16. Half-life is a means of classifying the rate of decayof radioisotopes according to the time it takesthem to lose half of their strength/intensity. Thehalf-life of U-238 is 4.51 billion years.

17. The time between exposure and the first signsof radiation damage is called the latent period.The larger the dose, the shorter the period.

18. The pool of health experience data was obtainedfrom the following sources: early radiation work-ers; medical personnel who routinely adminis-tered radiation for diagnostic and therapeuticpurposes; patients who were treated with radi-ation; a group of workers who painted dials withluminous paints containing radium; studies ofJapanese atomic bomb survivors.

19. For external radiation exposure hazards, the basicprotection measures are associated with time,distance, and shielding.

20. A safe distance is the distance nonoperatingworkers must maintain from the radiation sourcein order to receive no more exposure than thatspecified in the NCRP Radiation ProtectionGuides, even if personnel were to remain at thatdistance continually.

21. Potential avenues of exposure to the public arecontaminated air or water, waste materials, oremployees unknowingly leaving the place of work with contamination on their persons,clothing, or shoes.

22. A glove box is a type of hood that permits rigidcontrol of conditions when radioactive metalsare worked.

23. A radioisotope is a radioactive isotope of an ele-ment. It can be produced by placing material ina nuclear reactor and bombarding it with neu-trons. Many fission products are radioisotopes.They are sometimes used as tracers or as energysources for chemical processing, food pasteurization, and nuclear batteries.

24. The rapidly dividing cells of a fetus are moresusceptible to radiation damage than are maturecells. Women of childbearing age who may beexposed to radiation should be informed of the

need to protect the fetus from excessive or unnec-essary radiation exposure. Severe defects canresult from excessive exposure to radiation.

25. Thermoluminescence detectors (TSDs) are usedfor radiation exposure monitoring of gamma,x-, and beta-radiation. These dosimeters can beworn by the person as body badges or fingerrings. Most commonly they are small chips oflithium fluoride. A major advantage of the TLDsis that for x- and gamma-radiation they requireno energy source to operate in exposures of 20keV and higher. The ionizing radiation energyabsorbed by the TLD displaces from theirground state those electrons on the TLD. Theelectrons are trapped in the metastable statebut can be returned to the ground state by heating. When electrons return to the groundstate, light is emitted. A TLD readout instru-ment is used to precisely control heating the chip and measuring the light that is thenemitted from it. The amount of light releasedis related to the absorbed radiation dose and,in turn, to the radiation exposure of the individual.


1. The term nuclear radiation describes all forms ofradiation energy that originate in the nucleus ofa radioactive atom.

2. Some materials are naturally radioactive. Others can be made radioactive in a nuclear reac-tor or accelerator.

3. The most commonly encountered types of ionizing radiation are alpha-, beta-, and neutronparticles and x- or gamma-electromagnetic radiation. Other types are encountered in spe-cialized fields.

4. The effects on organs or tissues depend on thetype and energy of the radiation and their resi-dence time within the body. The effects of irra-diation on living systems are studied by lookingfor effects on the living cells, changes in bio-chemical reactions, evidence of production ofdisease, and changes in life or normal growthpatterns. The ionization process destroys thecapacity of reproduction or division in some cellsand causes mutation in others. Types of injuriesinclude dermatitis and cancer.

10 • Ionizing Radiation


5. The health data was obtained from early radia-tion workers, medical personnel who routinelyadministered radiation for diagnostic and ther-apeutic purposes, patients who were treated withradiation, a group of workers who painted dialswith luminous paints containing radium, andstudies of Japanese atomic bomb survivors.

6. Student should demonstrate their understand-ing of monitoring instruments by briefly describ-ing in a sentence or two how each one works.For full descriptions of these items, please seepages 268-269 of the accompanying text.

7. None of these monitoring instruments is uni-versally applicable.

8. They will need to ascertain the required level ofradiation protection and evaluate the problemsthat might arise by analyzing the radiation workin terms of the following factors: area involved,number of rooms and buildings; number ofemployees exposed to radiation and in whatlocations; chemical and physical states of theradioactive material and the nature of its use;incidents that might occur and their possiblelocations; nonradiation hazards involved; natureof the probable radiation exposure or release ofradioactive material; inherent danger of thematerial; probability of detection of hazardoussituation by routine surveys or monitoring;knowledge of current conditions; and possibleeffects of accidents on operations.

Chapter 11Nonionizing RadiationANSWERS—Quiz 1

1. a

2. b

3. a

4. b

5. a

6. b


24

7. d

8. b

9. a, d

10. c

11. The polarity and strength of the current keepsalternating between positive and negative, so itis called alternating current.

12. In the United States, polarity changes occur 60times a second.

13. The basic law of electrical engineering, Ohm’slaw, states that volts equals current times resist-ance or, by units, volts equals amps times Ohms (V = I × R).

14. The speed of electromagnetic radiation is thesame in air and in a vacuum, about 300,000,000m/s or about 186,000 mi/s.

15. The 2001 TLV for DC electric fields from 0 Hzto 100 Hz is 25 kV/m as a ceiling limit (a limitthat should not be exceeded for any length of time).

16. Artificial cardiac pacemakers can be fooled byambient electric and magnetic fields.

17. Magnetic fields are controlled using permeablealloy that confines the magnetic flux lines anddiverts them.

18. Microwaves are the portion of the radio-frequency spectrum ranging from 300 MHz to300 GHz.

19. The present emission standard for microwaveovens allows new ovens to leak no more than 1mW/cm2 when measured at 5 cm, and old ovensto leak no more than 5 m/cm2 when measuredat 5 cm.

20. UV-B and UV-C produce two undesirable effects:the skin toughening evident among desertdwellers and skin cancer.

21. Magnetic fields are often measured with loopsof conducting wire. The lines of magnetic fieldpassing through the loop induce current flow.


The field can be calculated by measuring theamperes of induced current and dividing thatby the circumference of the loop.

22. Electric fields can be measured by inserting adisplacement sensor, a pair of flat conductiveplates, into the field and measuring the elec-tric potential between the plates. The surveyormust stand away from the detector because thesurveyor’s body will shield the detector andcreate a falsely low measurement. Thus, theseinstruments come with long nonconductivehandles.

23. The dose rate (rate at which energy is transferredto tissue) is called the specific absorption rate(SAR), expressed in watts of power depositedper kilogram of tissue (W/kg).

ANSWERS—Quiz 2

1. a

2. a

3. b

4. a

5. b

6. b, c

7. a

8. a

9. a

10. Optical radiation and laser safety standards useradians rather than degrees as a measure of angle.

11. In optical radiation and laser safety standards,the steradian is used to describe portions of thesurface of a sphere.

12. Laser is an acronym for “light amplification bystimulated emission of radiation.”

13. The potential health effects from lasers are ther-mal burns, photochemical injuries, and retinaldamage. The other hazards of laser use, exclud-ing weapons, are electricity and fire.

14. The units of illuminance are the lux and the foot-candle.

15. It is generally agreed that radiation is likely tobe found at frequencies above 300 MHz.

16. An object absorbs the most radiation energy if itis about 40 percent of the wavelength and notwell grounded, or when it is about 20 percent ofthe wavelength and well grounded.

17. Radiofrequency standards rely on another inter-val, the thermal equilibrium of the target organs(the eyes and testes), which is assumed to be sixminutes.

18. The Swedish MPR standards are emission stan-dards, rather than exposure standards, for videodisplay terminals (or video display units).

19. A Faraday cage is a grounded enclosure madeof continuously bonded conductors. An objectinside is protected from electric fields and radi-ation on the outside.

20. Lasers are hazardous to eyes because they candeposit damaging amounts of energy into theeye well before the aversion reflex (blinking orlooking away) ends the exposure.

21. OSHA’s original regulation was struck down bythe Occupational Safety and Health ReviewCommission in 1981, but the UAW, Brock v. General Dynamics Land Systems Divisiondecision allows OSHA to apply state-of-the-artstandards developed by others when OSHA hasno standard of its own. So OSHA can enforceANSI/IEEE C95.1-1991.

22. Lasers work by pumping the electrons in a suit-able material, the lasing medium, with strongenergy and directing some of that energy out inthe form of a beam of radiation.

23. Visible and IR-Alasers produce retinal damage bya mechanism unique to lasers. The highly focusedbeam generates a steam bubble near the retina thatpops, sending shock waves into the retinal tissuethat produce thermo-acoustic tissue damage.


1. The first laser pointers were helium-neon (Class

11 • Nonionizing Radiation


2 lasers) emitting at 632 nm, but they were delicate because of the glass envelope of the He-Ne laser.

2. Diode lasers (Class 3a), emitting at 670 nm,replaced He-Ne lasers because they are morerugged and compact. Newer diode pointers emit-ting at 635 nm are now available.

3. The classes of lasers are a series of defined stepsas the output of the laser increases from Class 1(so low-powered as to be intrinsically safe)through Class 4 (very dangerous). Class 2 lasersare visible light lasers that could produce exces-sive exposures if viewed for more than the 0.25sresponse time to the average reflexes. Class 3moderate-power lasers warrant more precau-tions. The old He-Ne pointers bore a cautionlabel; the original diode pointers bear dangerlabels.

Chapter 12Thermal StressANSWERS—Quiz 1

1. b

2. a

3. a

4. b

5. a

6. c

7. c

8. a

9. c

10. d

11. b

12. The three factors that influence the degree ofthermal stress felt by a worker are the climatic

conditions of the environment, work demands,and clothing.

13. Increased metabolism results in increased ratesof heat gain because the conversion from chem-ical energy to kinetic energy is inefficient.

14. The equation for local heat storage is: Slocal = K + Dwhere K is conductive heat transfer between theskin and an object and D is the rate of heat trans-fer to or from the local area by conduction throughlocal tissue and by the heat supplied or removedvia local blood flow.

15. If heat stress is episodic, it is assessed in termsof safe exposure times for a given level of heatstress.

16. Three ways of controlling diffuse sources of radi-ant heat include shielding, insulating surfacesto reduce surface temperature, and decreasing asurface’s emissivity.

17. Two physiological responses to cold stress areshivering and reduced blood circulation throughthe skin.

18. When workers are at risk for cold stress, the gen-eral controls that should be implemented includetraining programs, hygiene practices, and med-ical surveillance.

19. The skin is the site of heat exchange with theenvironment. The heat generated by muscularwork warms the tissues deep inside the body,generally resulting in an increase in the body’score temperature. Blood circulating through thecore picks up heat energy and is then directedto the skin where it is cooled through a processcalled convection. Convection is the exchange ofheat between the skin and the surrounding air.If the surrounding air is cooler than the skin, heatflows from the body and it is cooled. The skinalso cools the body by producing sweat, whichremoves heat energy from the skin’s surface asit evaporates. As people become acclimated toheat stress, they sweat more and increase theirbody’s ability to cool itself.

20. Hypothermia is one example of a systemic hazard associated with cold stress. It has manycauses, including excessive exposure, exhaus-tion, and dehydration. Hypothermia can also



affect those people who have a subnormal tolerance, either genetic or acquired, for coldstress. It can also follow drug and alcohol abuse.As hypothermia progresses, the central nerv-ous system becomes more and more depressed.This process results in the signs and symptomsof the disorder: slurred speech, unconscious-ness, and fatigue. Fatigue causes the metabolicrate to diminish and blood flow to the skin todecrease, making the skin and underlying tis-sues more susceptible to local cold injury andincreasing the risk of severe hypothermia. Firstaid for hypothermia includes moving the victim to a warm area and removing any wetclothing; offering modest external warming withblankets, heat packs, etc.; providing warm,sweet fluids to the victim if he or she is conscious; and transporting the victim to a hospital.

ANSWERS—Quiz 2

1. a

2. a

3. b

4. b

5. a

6. b

7. d

8. d

9. a

10. c

11. b

12. The general equation for thermal balance is: S =(M + W) + R + C + K + (Cresp + Eresp) + E where Sis heat storage rate, M is metabolic rate, W isexternal work rate, R is radiant heat exchangerate, C is convective heat exchange rate, K is con-ductive heat exchange rate, Cresp is rate of con-vective heat exchange by respiration, Eresp rateof evaporative heat loss by respiration, and E israte of evaporative heat loss.

13. The three major characteristics of clothing thataffect thermal balance are insulation, perme-ability, and ventilation.

14. The physiological adaptations to thermal stressare increased body temperature, heart rate, andsweating.

15. The four environmental factors central to eval-uating heat stress are air temperature, humidity,air speed, and the average temperature of solidsurroundings.

16. There are four main topics that should be cov-ered during periodic heat-stress training ses-sions: describing what heat stress is, recognizingand providing first aid for heat-related disor-ders, explaining heat stress hygiene practices,and providing an overview of heat stress policyand guidelines.

17. When temperatures fall below 16 C (61 F), stepsshould be taken to implement workplace mon-itoring.

18. Physiological demands are modest and produc-tivity greatest in the comfort zone of the thermalstress continuum.

19. The following four questions can be asked inorder to determine whether workplace condi-tions should be evaluated for heat stress: (1) Thefirst question addresses environmental and work-ing conditions: Is the environment recognizedas being hot, are the work demands high, or isprotective equipment required? (2) The secondquestion examines worker behavior: Are workerbehaviors indicative of attempts to reduce heatstress, is morale low or absenteeism high, or arepeople making mistakes or getting hurt? (3) Thethird and fourth questions relate to medical issuesand trends seen in workers over time. The thirdquestion is: Do medical records show a patternof fatigue, weakness, headache, rashes, or highbody temperature? (4) The fourth question cov-ers high body temperature, heart rate, and sweatlosses in samples of workers. If the answer toany of these questions is “yes,” an evaluationprobably needs to be conducted.

20. Engineering controls reduce or contain a hazard.In terms of heat stress, engineering controls areaimed at reducing physical work demands,

12 • Thermal Stress


reducing external heat gain from the air and hotsurfaces, and enhancing external heat loss byincreasing sweat evaporation and decreasing airtemperature. Some examples of engineering con-trols include using dilution ventilation and activecooling to reduce air temperature and using fansto increase air movement.

Administrative controls change the way thatwork is performed in order to limit exposures orrisks. Administrative controls for heat stress focuson limiting exposures so that increases in heartrate and core temperature do not exceed acceptedlimits. Pacing work, sharing work, and adjust-ing schedules to accommodate for heat exposureare all examples of administrative controls.


1. Heat stress in the workplace can be recognizedin terms of workplace risk factors and in termsof the effects it has on workers. Three workplacerisk factors for heat stress are traditionally rec-ognized: hot environments, high work demands,and protective clothing requirements. In essence,if the workplace is generally considered hot,based on the subjective judgment of workers andsupervisors, then heat stress may be a concern.If the demands for external work are high, heatstress may be a factor in environments that areconsidered comfortable by casual observers orothers not exerting themselves in the environ-ment. Lightweight, loose-fitting clothing is theensemble of choice for potential exposures toheat stress. In some cases, however, protectiveclothing may decrease permeability and venti-lation and increase insulation. The added weightof personal protective clothing may increase themetabolic heat load and, as a result, the level ofheat stress. Workers loading and unloading mate-rials could be exposed to a hot outside environ-ment and high work demands. Workers askedto retrieve materials from outside the facility aresusceptible to heat stress for the same reasons.If both sets of employees require protective cloth-ing to do their jobs, they are also likely candi-dates for heat stress.

Heat stress can also be recognized by observingworkers’ behavior. Workers often do things thatreduce their exposure to heat. For example, theymay adjust their clothing to increase the effectsof evaporation, they may work at a slower pace,

they may take short breaks to lower their meta-bolic rates, or they may take short cuts in workmethods. Workers may also seem more irritable,have low morale, and be absent more often.When heat stress is a concern the number oferrors made by workers tends to increase,machines break down more often, unsafe behav-ior is seen more frequently, and accidental injuriesincrease.

2. In extreme cases, heat stress results in heat-relateddisorders. Some common heat stress disordersinclude heat rash, heat exhaustion, and dehy-dration. Other important heat-related disordersare heat stroke, heat syncope, and heat cramps.Heat stroke is the most serious heat-related dis-order, while heat exhaustion is the most common.Dehydration is a precursor to heat exhaustion,but it is usually not noticed or reported by employ-ees. Even if a specific heat-related disorder is notmentioned in a worker’s medical records, heatstress may have affected the worker in the formof faintness, weakness, nausea, cramps, headaches,and skin rashes. A worker suffering from heatstress may have a high temperature, or theworker’s urine samples may have a high specificgravity caused by dehydration.

Chapter 13ErgonomicsANSWERS—Quiz 1

1. a

2. a

3. b

4. a

5. a

6. b

7. c

8. a

9. c



10. c

11. c

12. People perform widely differing tasks in dailywork situations. These tasks must be matched withhuman capabilities to avoid underloading, inwhich human capabilities are not sufficiently used,as well as overloading, which may cause theemployee to break down and suffer reduced per-formance capability or even permanent damage.

13. Affordance is the property of an environment thathas certain value to the human. (The student willmost likely provide the following example fromthe book, although any reasonable example willbe satisfactory.) An example is a stairway thataffords passage for a person who can walk butnot for a person confined to a wheelchair. Thus,passage is a property of the stairway, but its affor-dance value is specific to the user. Accordingly,ergonomics provides affordances.

14. The time passing from the appearance of a prox-imal stimulus to the beginning of an effectoraction is called reaction time. The additional timeto perform an appropriate movement is calledmotion or movement time. Motion time added toreaction time results in the response time.

15. An individual’s capacity for work is usuallydetermined by the limits of his or her respira-tory and cardiovascular systems to deliver oxy-gen to the working muscles and by the limits ofthe metabolic system to use chemically storedenergy to do muscular work.

16. The simplest technique for heart-rate assessmentis to palpate an artery, often in the wrist. Themeasurer counts the number of heartbeats overa given period of time—such as 15 seconds—and then calculates the average heart rate perminute.

17. Anthropometry literally means measuring thehuman, traditionally in metric units of heights,breadths, depths, and distances—all straightline, point-to-point measurements between land-marks on the body and/or reference surfaces.Also, curvatures and circumferences followingcontours are measured, as is weight. In one stan-dard posture, the subject is required to standerect (heels together; buttocks, shoulder blades,

and back of head touching the wall) with armsvertical and fingers straight. The second pos-ture is employed when measurements are takenon a seated subject.

18. Assessment of human muscle strength is a bio-mechanical procedure. This assessment usesNewton’s Second and Third Laws, which statethat force is proportional to mass times acceler-ation, and that each action is opposed by anequivalent reaction. Since human musclestrength currently is not measured at the mus-cle in vivo and in situ, human strength isdescribed by the amount of force or torqueapplied to an external measuring instrument—which is the kind of data that the engineer needsto design tools and equipment.

19. Fatigue is operationally defined as a reducedmuscular ability to continue an existing effort.Anaerobic metabolism—which plays an increas-ing role as the energetic work demands exceedabout half the person’s maximal oxygen uptake—results in accumulations of potassium and lac-tic acid, believed to be the primary reasons formuscle fatigue. Avoid fatigue by allowing shortbursts of dynamic work and avoiding long peri-ods of static effort. Keep energetic work and mus-cle demands low. Encourage taking many shortrest pauses; this is better than taking a few longbreaks.

20. The student must show a general understand-ing of the guidelines that would enable a workerto perform his task safely and efficiently. Thesemight include:• If people must move material, make sure the

movement is predominantly in the horizontalplane. Push and pull, rather than lift or lower,and avoid severe bending of the body.

• If people must lift or lower material, let themdo so between knuckle height and shoulderheight. Lifting and lowering below knuckleheight or above shoulder height are most likelyto result in overexertion injuries.

• If lifting and lowering must be done by people, make sure these activities occur closeto and in front of the body. If the worker mustbend forward or, worse, twist the body sideways, overexertion injuries are mostlikely.

• If people must move material, make sure thematerial is light, compact, and safe to grasp. A

13 • Ergonomics


light object will strain the spinal column andbody tissues less than heavy objects. Compactmaterial can be held more closely to the bodythan a bulky object. A solid object with goodhandles is more safely held and more easilymoved than pliable material.

• If people must handle material, make sure itdoes not have sharp edges, corners, or pinchpoints.

• If material is delivered in bins or containers,make sure it can be easily removed from them,particularly that the operator does not have to“dive” into the container to reach the material.

• People tend to revert to previous habits andcustoms if practices to replace previous onesare not reinforced and refreshed periodically.

• Emergency situations, the unusual case, thesudden quick movement, increased bodyweight or impaired physical well-being mayoverly strain the body, since training usuallydoes not include these conditions.

• If the job requirements are stressful, “doctoringthe system” through behavioral modificationwill not eliminate the inherent risk. Designinga safe job is basically better than training peo-ple to behave safely in an unsafe job.

ANSWERS—Quiz 2

1. a

2. b

3. b

4. b

5. a

6. d

7. a

8. b

9. a

10. d

11. a

12. Kroemer’s seven keys for safe and efficientmaterial handling are as follows: Facility Lay-

out, Job Design, Equipment, People, TrainingMaterial Handlers, Screening Material Han-dlers, and Ergonomic Design of Workplace andWork Task.

13. Biomechanical and physiological research hasshown that the leg muscles used in this liftmethod do not always have the needed strength.Also, awkward and stressful postures may beassumed if one tries to enforce this techniqueunder unsuitable circumstances. Hence, thestraight-back/bent-knees action evolved into thekinetic lift, in which the back is kept mostlystraight while the knees are unbent, but feet, chin,arm, hand, and torso positions are prescribed.Other variants include the freestyle lift and thestoop lift. Overall, the student should have anunderstanding that there is no single liftingmethod that is best for all situations.

14. The equation is used for calculating the Recom-mended Weight Limit. LC is the Load Constant,HM represents the Horizontal Multiplier, VM isthe Vertical Multiplier, DM is the Distance Mul-tiplier, AM is the Asymmetry Multiplier, FM isthe Frequency Multiplier, and CM is the Cou-pling Multiplier.

15. The student should mention the philosophybehind wearing belts: When humans prepare tolift or lower a load, they instinctively developintra-abdominal pressure within the trunk cav-ity. This pressure is believed to help support thecurvature of the spine during the lifting or low-ering effort. An external belt around the abdom-inal region might help to maintain the internalpressure because it makes the walls of the pres-sure column stiffen. However, studies do not sup-port or condemn the wearing of a belt in industrialjobs and the use of lifting belts for professionalmaterial handling does not seem to be an effec-tive way of preventing overexertion injuries.

16. The five general rules that govern space designare (1) Plan the ideal, then the practical. (2) Planthe whole, then the detail. (3) Plan the workprocess and the equipment to fit the human. (4)Plan the workplace layout around the processand the equipment. (5) Use mockups to evalu-ate alternative solutions and to check the finaldesign.

17. Complaints related to posture (musculoskeletal



pain and discomfort) and vision (eye strain andfatigue) are, by far, the most frequent health prob-lems voiced by computer operators. Improperlydesigned workstations, ill-selected furniture, andpoorly arranged equipment are the principalcauses of postural problems.

18. Repetitiveness and forcefulness of tasks as wellas static muscle tension can contribute to CTDs.

19. A red signal light shall be used to alert an oper-ator that the system or any portion of the systemis inoperative or that a successful mission is notpossible until appropriate corrective or overrideaction is taken. A flashing red signal light is usedto denote emergency conditions that requireimmediate operator action or to avert impend-ing personnel injury, equipment damage, or both.A yellow signal light shall be used to advise anoperator that a marginal condition exists. Yellowshall also be used to alert the operator to situa-tions for which caution, rechecking, or unex-pected delay is necessary. A green signal shallindicate that the monitored equipment is in sat-isfactory condition. A white signal light shall beused to indicate system conditions that do nothave right or wrong implications, such as alter-native functions or transitory conditions. A bluesignal light may be used as an advisory, but com-mon use of blue should be avoided.

20. The student needs to demonstrate an under-standing of the range and scope of cumulativetrauma disorders. Although specific examplesof trauma will vary by student, most will touchupon these body components: soft tissues (ten-dons, bursa, ligaments, etc.), nerves, blood ves-sels, joints, muscles, etc.


1. Writer’s cramp is another name for carpal tun-nel syndrome. It is the result of repetitive pres-sure on the median nerve in the carpal tunnel ofthe wrist. It is trigged by rapid, often repeatedfinger movements and wrist deviations; in thiscase, it is probably caused by typing or keyingin data. Work behavior should be modified toallow employees to perform alternate tasks toavoid so much time on the computer.

2. Until recently, it was believed that an uprighttrunk was part of a healthy posture. This idea

had been used to design office chairs and otherfurniture. However, today there are no com-pelling physiological or orthopedic reasons tomake people stand or sit straight. This postureis impractical for working since employees moveabout instead of standing stiff and still. Main-taining any body position remains unpleasantafter a while.

3. The free-flowing motion design idea has the fol-lowing basic tenants:• Allow the user to freely move in and with the

chair and to halt at will in a variety of sittingpostures, each of which is supported by thechair, and to get up and move about.

• Make it easy for the user to adjust the chairand other furniture, especially keyboard anddisplay, to the changing motions and postures.

• Design for a variety of user sizes and user preferences.

• Consider that new technologies developquickly and should be usable at workstations.

4. Visual interface, manipulation, and body sup-port are the links between a person and a task.

Chapter 14Biological HazardsANSWERS—Quiz 1

1. a

2. b

3. b

4. a

5. a

6. a

7. a, b

8. a

9. c, d

10. c

14 • Biological Hazards


11. The appearance of a virus capable of destroyingthe human immune system (HIV) in the 1980s,coupled with the high incidence of occupation-ally acquired hepatitis B virus infection amonghealth care workers, prompted OSHA to estab-lish a standard that mandates protection of work-ers from occupational exposure to bloodbornepathogens.

12. Infection is an invasion of the body by pathogenicmicroorganisms and the reaction of the tissues totheir presence and to the toxins generated by them.

13. In addition to research, medical, and industrialfacilities involving laboratory animals, there isa wide range of occupations in which workersare exposed to animal-related allergens and toinfectious agents or their toxins. Agriculturalworkers, veterinarians, workers in zoos andmuseums, taxidermists, and workers in animalproduct-processing facilities are all at risk.

14. Controls for the zoonotic diseases considered tobe a hazard for agricultural workers includeawareness of specific hazards, use of personalprotective equipment, preventive veterinary care,worker education, and medical monitoring orprophylactic therapy, where appropriate.

15. The biosafety guidelines most commonly usedin the United States for containment of biohaz-ardous agents in the workplace are those rec-ommended by the Centers for Disease Controland Prevention (CDC), the National Institutesof Health (NIH), and the National ResearchCouncil (NRC).

16. One of the most critical workplace controls tominimize exposure to HIV, HBV, and HCV is thereduction of sharps-related incidents.

17. The infection control concept of universal pre-caution is that all human blood and certainhuman body fluids are to be treated as if knownto be infectious for HIV, HBV, HCV, and otherbloodborne pathogens.

18. The components of an epidemiological investi-gation of any disease outbreak (natural or arti-ficial) are (1) documentation of who is affected;(2) identification of possible sources and routesof exposure; (3) recording of signs and symp-toms of disease; and (4) rapid identification of

the causative agent.

19. Health effects consistent with endotoxin expo-sure include fatigue, malaise, cough, chest tight-ness, and acute airflow obstruction.

20. Organic dust toxic syndrome appears to resultfrom inhaling particles and toxins produced bymicroorganisms.

21. Infectious airborne particles can be generatednot only from aerosolized liquids but also fromlyophilized cultures, dried bacterial colonies,dried material on stoppers and caps of culturetubes and bottles, dried exudates, fungal andactinomycete spores released when cultures areopened or contaminated material is disturbed,and dusts from animals.

22. Primary containment, or protection of workersand the immediate work environment, isachieved through the use of good work practicesand appropriate safety equipment. Effective vac-cines also decrease worker risk.

23. Secondary containment, or protection of per-sonnel in the immediate area outside the labo-ratory and the community (environment externalto the workplace), is attained by using adequatelydesigned, constructed, and maintained facilitiesand operational practices.

ANSWERS—Quiz 2

1. a

2. b

3. b

4. a

5. a

6. c

7. d

8. b

9. c

10. a, d



11. Microorganisms are a diverse group of micro-scopic organisms that includes bacteria, fungi,algae, protozoa, viruses, and prions.

12. Exogenous infections are infections from microor-ganisms not normally found in or on the humanbody, but which gain entrance from the envi-ronment.

13. The principal modes of transmission for infec-tious microorganisms and other biological mate-rials include contact transmission (direct orindirect), vector-borne transmission, and air-borne transmission.

14. Vector-borne infection results when a causativeagent is transmitted to a host mechanically orbiologically by a living vector (such as a mos-quito or tick) through a bite, directly through theskin in rare cases, or by mechanical means.

15. Foremost among the infectious hazards forwomen who are pregnant or intend to becomepregnant is the potential for congenital infectionof the fetus, due to exposure to cytomegalovirus(CMV), rubella, hepatitis B virus (HBV), herpessimplex virus, varicella virus, syphilis, or toxo-plasmosis.

16. The conditions are interrelated factors thatinclude route of entry, dose, viability, virulence,mode of transmission, and host susceptibility.

17. The most frequently used disinfectants in theworkplace include sodium hypochlorite (house-hold bleach), isopropyl or ethyl alcohol,iodophors (Wescodyne), and phenolics (Lysoland amphyl).

18. Hepatitis C virus is transmitted primarilythrough large and repeated direct percutaneousexposure to blood.

19. Much of the current increase in cases of tuber-culosis has been attributed to HIV-infected peo-ple, particularly in Africa and Southeast Asia.

20. Tuberculosis is usually transmitted by the inhala-tion of infectious droplet nuclei suspended in theair, from coughing, sneezing, singing, or talking.

21. Large water supplies have not been consideredattractive targets for bioterrorists due to the large

amount of an agent that would be required andthe water purification procedures used in mostU.S. cities.

22. Typical indoor sources of biological agents thatcan cause adverse health effects are (1) people,who shed bacteria and viruses; (2) building mate-rials, furnishings, and ventilation system com-ponents that provide a suitable environment fororganism survival and growth; (3) accumula-tions of biological materials on indoor surfaces,and (4) animals that shed allergens.

23. Modern demographic and ecologic conditionsthat favor the spread of infectious diseasesinclude rapid population growth; increasingpoverty and urban migration; more frequentmovement across international boundaries bytourists, workers, immigrants, and refugees; alter-ations in habitats of animals and arthropods thattransmit disease; increasing numbers of personswith impaired host defenses; and changes in theway food is processed and distributed.

24. Biosafety program components usually includeprogram support, a biosafety officer or special-ist, an institutional biosafety committee (IBC), abiosafety manual of written policies and proce-dures, an occupational health program for rele-vant employees, and employee training orinformation communication.

25. Key elements of an effective response plan to abioterrorism attack include prompt recognitionof the incident, staff and facility protection, decon-tamination and triage of potentially exposed per-sons, medical therapy, and coordination withexternal emergency response and public healthagencies.


1. Many investigations of problem buildings arebased on the development and testing ofhypotheses, carefully formulated, logical answersor explanations. Investigators combine availableenvironmental, epidemiological, medical, andtoxicological evidence to develop hypotheses,then devise ways to check these theories to deter-mine which are consistent with available infor-mation.

2. There is little formal regulation in this area, and

14 • Biological Hazards


few guidelines are based on health criteria or areenforceable. Evaluating indoor environmentalquality can be a challenging endeavor. Beforemeasuring air concentrations for biologicalagents, investigators are encouraged first toexhaust other approaches (such as medical eval-uation of affected individuals and identificationof their illnesses) as well as analysis and correc-tion of deficiencies in building design, mainte-nance, and operation.

Chapter 15EvaluationANSWERS—Quiz 1

1. b

2. b

3. b

4. a

5. b

6. b

7. d

8. c

9. d

10. a

11. b

12. Required by OSHA’s Hazard CommunicationStandard, 29 CFR 1910.1200, chemical invento-ries are used to anticipate possible hazards andto ensure these risks are communicated toemployers and employees before they areencountered in the workplace.

13. Process safety management is a systematicapproach to evaluating an entire process for thepurpose of preventing unwanted releases of haz-ardous chemicals into locations that could exposeemployees and others to serious hazards.

14. The three categories of biological monitoring are(1) measurement of the contaminant, (2) meas-urement of a metabolite of the chemical, and (3)measurement of enzymes or functions that reflectharm caused by hazardous exposure.

15. The employer must either provide alternativework in an area where there is not risk of expo-sure or allow the worker to stay home and receivefull compensation during the treatment period.

16. Accuracy concerns the relationship between ameasured value and the true value. For a meas-urement to be accurate, it must be close to thetrue value.

17. OSHA distinguishes between full-period, con-tinuous single samples; full-period consecutivesamples; and grab samples.

18. When existing documentation does not showthat exposure levels were constant, any worktime for which no samples were collected mustbe considered as unexposed time, and a zero isfactored into any calculation of the time-weightedaverage (TWA).

19. The first step toward identifying a potential haz-ard is to examine the raw materials being used,including any known impurities, and the poten-tial of these materials to do harm. The next con-sideration is how these materials are modifiedthrough intermediate steps. Finally, the finishedproducts or by-products should be evaluatedunder normal conditions and under anticipatedemergency conditions. The questions that shouldbe asked during the evaluation procedureinclude: what are the raw materials, what is pro-duced, what intermediate products are formedin the process, and what by-products may bereleased. Questions about usual cleaning andmaintenance procedures and hazardous wasteproduction and disposal should also be asked.The industrial hygienist should use these ques-tions to organize the information gathered dur-ing the evaluation.

20. To ensure accuracy and precision when sampling,several guidelines should be followed. First, themanufacturer’s information for direct-readinginstruments should be obtained whenever pos-sible. It should state the accuracy and precisionof the method to be used. A calibration schedule



should be established and documented for allequipment used in the sampling process. TheNIOSH Manual of Analytical Methods should beconsulted for accuracy and precision of the methods chosen. When results of the samplingare reported, the NIOSH sampling method shouldbe noted. Finally, only laboratories that partici-pate in industrial hygiene quality control pro-grams should be used to analyze the samples.

ANSWERS—Quiz 2

1. b

2. a

3. a

4. b

5. a

6. b

7. d

8. d

9. a

10. c

11. d

12. The unequal distribution of risks means beingaware that some populations of workers are morelikely to have a higher risk of disease and injuryin the workplace.

13. Workers should be asked about the content ofthe their jobs, how they spend their time, if anyexposures of concern exist, and if they havenoticed any health symptoms, especially thoserelated to contact with chemical products orprocesses.

14. The increased risk of lung cancer that resultsfrom smoking and asbestos exposure is an example of a synergistic or additive effect.

15. The two factors that must be considered are airmovement patterns and differences in workhabits.

16. The number of samples that needs to be collecteddepends on the purpose of the sampling, thenumber of different tasks a worker performs ina given day, and the variability inherent in thecontamination generation process.

17. The formula for calculating the TWA for an eight-hour workday is: C1T1 + C2T2 + CNTN / 8 hours,where C is the concentration of the contaminantand T is the time period during which this con-centration was measured.

18. If published standards or guidelines do not exist,industrial hygienists can refer to internal stan-dards developed by the manufacturer, reportspublished in industry literature, health surveysamong those exposed on the job, or animal tox-icology data.

19. Since most airborne concentrations fluctuate overtime, only extensive, continuous area samplingcan provide information about changes in con-centration levels in a given location. In-deptharea monitoring is not done routinely because itis a lengthy process and requires large amountsof equipment. Although this equipment can bemade rugged and reliable, often this is not thecase. Leaving the equipment unattended forhours or days without the supervision of atrained technician could result in unreliable datacollection during an important step in a process.In addition, area sampling may underestimatean employee’s exposure if he or she works closeto a process, but the measurement probe or col-lection device is located away from the point ofexposure.

20. The first advantage of the worst-case strategy isthat it is designed to solve a problem. By meas-uring the concentration of the chemical thoughtto have caused the health symptoms, the indus-trial hygienist helps identify the source, improvethe controls, and correct the problem. Second,the results teach employees valuable lessonsabout indicators of equipment malfunction, thewarning signs of overexposure, and the impactof work practices on the levels of airborne con-taminants. Finally, by evaluating the worst caseduring the longest exposure time to the highestexpected concentration and by comparing theresults to relevant PELs, STELs, TLVs®, and RELs,the industrial hygienist is able to make assump-tions about shorter-term, lower-level exposures.

15 • Evaluation



1. Typical-day sampling is one approach to air sam-pling, but it is not as easy as it sounds. Daily vari-ations may make typical exposure difficult todefine and measure. The managers and employ-ees being monitored may take extra precautionswhen they know they are being observed. Inaddition, concerns about being “sampled” maylead companies to present their best face byadding ventilation or opening doors and win-dows that are usually closed. Following the typ-ical-day method, preliminary air sampling isusually done on the day shift, when supervisionis better, shipping doors are more likely to beopen, and the timer for the ventilation system ison the occupied setting. Since both the typical-day and the worst-case scenario methods havedrawbacks when used independently, a goodsampling strategy makes use of both methods.Fingston Labs should probably incorporate sometypical-day sampling into its hazard evaluationprocess.

2. Biological monitoring is one way of comparingexposure to dose; however, it measures expo-sure only after it occurs, and after the contami-nant has affected the body in some way. It mustnot be used as the sole control measure, as issometimes the case when employers want tospare the cost of a more comprehensive, expen-sive monitoring program. Biological monitoringand medical surveillance should not replace envi-ronmental, or area, sampling or personal sam-pling. Instead, a combination of all four types ofmonitoring should be used.

3. When it comes to deciding which employees tosample, it is important to begin by determiningwhich employee is the most highly exposed,especially if the initial results of monitoring sug-gest the possibility of excessive exposure. Oneway of doing this is to observe the point of releaseof the contaminant and select the employee whois closest to it. This determination can be com-plicated by other factors, such as air movement.For example, in processes involving heating orcombustion, the natural air circulation could besuch that the maximum-risk employee might beworking at a considerable distance from thesource. Ventilation booths, air supply inlets, andopen doors also affect airflow patterns. In addi-tion to airflow, differences in work habits can

significantly affect levels of exposure. Eventhough several employees work with the samematerials, their methods and habits could affectthe contaminant concentration to which they areexposed. If it is only testing at locations knownto have been problematic in the past, Fingstonmay not be testing all of its most highly exposedemployees.

4. A process flow sheet helps to show how andwhere each material is introduced into aprocess and at what points products and by-products are created. Process flow sheets andstandard operation procedures (SOPs) shouldbe updated as new elements are incorporatedinto a process because they provide a gooddescription of the general operations involvedand an excellent source of industry terminol-ogy. Since many hazards exist simultaneously,it is important to examine the overall process,identify air contaminants, and pinpoint thelocation and tasks of employees who might beexposed to them. Having updated process flowsheets that show where and how changes havebeen made to manufacturing process at Fin-gston would help the company implement amore efficient and effective hazard evaluationprocess.

Chapter 16Air Sampling

ANSWERS—Quiz 1

1. b

2. a

3. a

4. a

5. a

6. d

7. a

8. b



9. d

10. b

11. A breathing zone is defined as a hemisphere infront of the shoulders with a radius of 6 to 9inches.

12. Air-sample collection devices are made of fivebasic components: an air inlet orifice, a collec-tion device, an airflow meter, a flow-rate controlvalve, and a suction pump.

13. Breakthrough describes a condition in which themass of a collected gas or vapor in the backupsection is greater than 10 percent of the mass inthe front section. This means that a significantquantity of the contaminant may not have beencollected. The calculated concentration, there-fore, is of questionable validity.

14. A wet-test meter is a partitioned drum, half-submerged in liquid, with openings in the cen-ter and periphery of each radial chamber. Air orgas enters at the center and flows into one com-partment, causing the chamber to rise and rotate.The number of revolutions made by the cham-ber is recorded on a dial. Because the liquid isreplaced by air, the measured volume dependson the height of the fluid, so a sight gauge is pro-vided. Temperature and pressure gauges arealso provided.

15. A rotameter consists of a float or ball that is freeto move in a vertically tapered tube. Air is pulledthrough the tube so that the ball rises until thereis an equilibrium between the force of gravityand the force of the air traveling upward. Theflow rate is determined by reading the height ofthe float on an attached numerical scale. Rotame-ters are frequently used in the field to checkpump flow rate periodically during full-shiftsampling.

16. A critical orifice is a precisely drilled hole in ametal plate through which the airstream beingsampled is directed. When certain parametersare met, the flow rate through the orifice remainsconstant despite conditions at the inlet (such asa clogged filter). A critical orifice attached to asampling pump causes the pump to draw air atthe desired flow rate. The principle of the method

is to draw air through the orifice under criticalflow conditions and constant upstream pressure.

ANSWERS—Quiz 2

1. b

2. b

3. a

4. a

5. a

6. a

7. c

8. d

9. a

10 A field blank is used to determine whether anair sample has been contaminated during han-dling.

11. The advantages of grab sampling are that it isinexpensive, it is simple to use, and it normallycollects 100 percent of the chemical. The disad-vantage is that usually it cannot be used to sam-ple reactive gases such as hydrogen sulfide,nitrogen dioxide, and sulfur dioxide unless thesamples are analyzed immediately. Reactivegases can react with atmospheric dust particles,other gases, moisture, container sealant com-pounds, or the container itself, producing erro-neous results.

12. Electrostatic precipitators are used when therequired sample air volume is large, high-col-lection efficiency is required for very small par-ticles such as fumes, there is a possibility of filterclogging, or high-temperature airstreams mustbe sampled.

13. The student must demonstrate a familiarity withthis form by describing any part of its contents.The complete form can be found on pages 541-542 of the text.

14. A thermal desorption tube may contain severaldifferent sorbents in order to collect a wide range

16 • Air Sampling


of different chemicals. It is usually used in situ-ations where unknown chemicals or a wide vari-ety of organics are present, e.g., in indoorenvironmental air quality investigations.

15. Certain numbers of blanks are required by theanalytical laboratory for each set of samples tobe analyzed. Media blanks are simply unopened,new samplers that are sent with the samples.These unexposed, unopened samplers will givean estimate of media background.

16. The selection of a sampling method depends onthe following factors:• the sampling objective (documenting expo-

sures, determining compliance, pinpointingsources of exposure)

• the physical and chemical characteristics ofthe chemical

• the presence of other chemicals that mayinterfere with the collection or analysis of thechemical

• the required accuracy and precision• regulatory requirements• portability and ease of operation• cost• reliability• type of sampling needed (area, personal,

grab, integrated)• duration of sampling


1. Personal air sampling is the preferred methodof evaluating worker exposure to airborne chem-icals. The worker wears a sampling device thatcollects an air sample. Area air samples can beused to evaluate background concentrations,locate sources of exposure, or evaluate the effec-tiveness of control measures. Grab samples aretaken to measure the airborne concentration ofa substance over a short period of time. Inte-grated air sampling is used to estimate a worker’s8-hour or 15-minute exposure to a particular sub-stance.

2. Air sampling is used to evaluate employee expo-sure, assist in the design or evaluation of controlmeasures, and document compliance with gov-ernment regulations.

3. Air-sample collection devices are made of fivebasic components: an air inlet orifice, a collec-

tion device, an airflow meter, a flow-rate controlvalve, and a suction pump.

4. Dusts, fumes, smoke, and fibers are dispersedas solids; mists and fogs are dispersed as liq-uids. They range in size from visible to micro-scopic.

5. The filter is the most common collection devicefor particulates.

6. Other sampling techniques include impactors,impingers, elutriators, electrostatic precipitation,thermal precipitation, and cyclones.

7. The selection of a sampling method depends onthe following factors:• the sampling objective (documenting expo-

sures, determining compliance, pinpointingsources of exposure)

• the physical and chemical characteristics ofthe chemical

• the presence of other chemicals that mayinterfere with the collection or analysis of thechemical

• the required accuracy and precision• regulatory requirements• portability and ease of operation• cost• reliability• type of sampling needed (area, personal,

grab, integrated)• duration of sampling

Chapter 17Direct-Reading Instrumentsfor Gases, Vapors, and ParticulatesANSWERS—Quiz 1

1. b

2. a

3. a

4. b



5. c

6. b, c

7. a

8. When certain proportions of combustible vaporare mixed with air and a source of ignition ispresent, a fire or explosion can occur. The rangeof concentrations over which this occurs is calledthe explosive (or flammable) range.

9. In the MOS gas sensor, a change in the electri-cal conductivity occurs when a combustible gasis adsorbed on the surface of a semiconductor.This change in electrical conductivity is pro-portional to the concentration of the combustiblegas present.

10. Limitations that must be considered when usingcolorimetric detector tubes include the sensitiv-ity of the tubes, their lower accuracy, the possi-ble presence of interferences, and the potentiallack of appropriate tubes for determining any-thing more than instantaneous concentrations.

11. The zero adjustment must be made by taking theinstrument to a location that does not containcombustible gases or by passing air into itthrough an activated carbon filter that removesall combustible vapors and gases (exceptmethane).

12. Portable or transportable electron capture detec-tors are used to evaluate fume hood perform-ance through the release of sulfur hexafluorideat the face of the hood.

13. The open path infrared analyzer is intended forthe detection of major leaks or spills of com-bustible or toxic gases within a distance ofroughly 200 m.

14. In gas chromatography, the components of avolatile mixture migrate differentially througha separating column, transported by a carrier gaspassing through the column. Optimally, differ-ential migration takes place and each compo-nent separates as a discrete substance.

15. In comparison to other detectors that have beenused for portable gas chromatographs, using amass spectrometric detector is advantageous

because the spectrometer has the ability to iden-tify compounds in an unknown mixture bymatching the fragmentation pattern of theunknown peak with that of knowns stored in aportable computer-based library.

16. The two principles that are the basis for com-bustible gas monitors are (1) the change in resist-ance of a conductor subjected to heat releasedby gas combustion, or (2) the change in electri-cal conductivity of a metallic oxide semicon-ductor in the presence of a combustible gas.

17. Many gases and vapors, both inorganic andorganic, absorb certain characteristic frequenciesof infrared radiation. This property and theresultant infrared spectrum can be used to iden-tify and quantify compounds in the air thatabsorb in the infrared region.

ANSWERS—Quiz 2

1. a

2. b

3. a

4. a

5. a, d

6. d

7. d

8. Air is drawn through the sampling probe andinto the detector by means of a small samplingpump or a hand-operated squeeze bulb. In somecases, air diffuses into the instrument withoutbeing actively drawn in.

9. Because minute concentrations of siliconevapors—even 1 or 2 ppm—can rapidly poisonthe catalytic activity of the platinum filament, ahot-wire combustible gas indicator should notbe used where silicone vapors are present.

10. Polarographic detectors rely on two parameters:(1) the ability of the compound of interest to bechemically oxidized or reduced at an electrodeat a given electrode potential, and (2) the rate-determining step of the discharge of ions at a

17 • Direct-Reading Instruments for Gases, Vapors, and Particulates


microelectrode that is determined by diffusion.

11. A number of direct-reading instruments are notcompound-specific or are specific for wholeclasses of compounds. These are of value as leakdetectors or in atmospheres that are know to con-tain only a single contaminant.

12. Flame ionization detectors are highly sensitiveto compounds that ionize in the presence of anoxyhydrogen flame. The ions are collected andthe electric current generated for the compoundof interest (whose response factor has been deter-mined) can be translated into a concentration.

13. The ion mobility spectrometer was developedfor rapid detection of toxic gases in combat sit-uations.

14. The condensation nuclei counter is a type ofhighly sensitive particulate monitor that is usedas a direct-reading instrument for the evaluationof fit factors in air-purifying respirators.

15. Great care must be exercised to ensure that areading above the UEL is not misinterpreted asa true zero reading. A very high concentrationof combustible gas can be identified by carefullywatching the needle as the probe is moved intoand withdrawn from the space being tested. Atsome point during entry and withdrawal, theinstrument will exceed the LEL if a level abovethe LEL is actually present.

16. The basic principle for surface acoustic wavedetectors is that acoustic waves are transmittedat a resonant frequency into a piezoelectric mate-rial. This material can be coated with a varietyof different absorptive polymers. The resonantfrequency is determined by the mass of thevapors present in the air that are absorbed bythe polymer. Changes in that frequency can bemeasured and translated into a signal that is pro-portional to the concentration of a particular con-taminant in the air.


1. In many confined spaces, the oxygen content canbecome low enough to be life-threatening. Insuch situations, it is necessary to determine theoxygen content of the air. It is also necessary to

take a sample to determine whether combustiblegases are present in dangerous concentrations.

2. The oxygen level should be monitored inenclosed areas where combustion or otherprocesses may use up the available oxygen.Excess oxygen from oxyacetylene or oxyhydro-gen flame operations should also be monitoredto prevent a fire hazard.

3. Multiple-gas monitors are available that canaccommodate up to five different detectors at a time. These instruments are typically config-ured to include combustible gases and vapors,oxygen, and carbon monoxide, all of which areof interest in confined spaces.

Chapter 18Methods of ControlANSWERS—Quiz 1

1. a

2. b

3. a

4. a

5. b

6. c

7. d

8. b

9. a

10. c

11. d

12. The three categories of methods are engineeringcontrols, administrative controls, and personalprotective equipment.

13. When more than one standard or agency isinvolved, the more stringent standard is assumed



to be controlling.

14. The five questions that should be asked are: towhat degree is it possible to remove hazardousresidues from a piece of equipment before it isopened, to what extent can a system be designedto be relatively maintenance-free, can a systembe designed so that the entire operation can beconducted as a closed system, can the process beconducted automatically without workerinvolvement, and can the system be cleaned auto-matically without worker involvement.

15. When isolating toxic materials, the degree of iso-lation that is required depends on the toxicity ofthe contaminant, the amount released, and workpatterns around the process.

16. The major disadvantage of general ventilationis that employee exposures can be very difficultto control near the source of the contaminantwhere sufficient dilution has not yet occurred.

17. An air-purified respirator removes a contami-nant from the breathing air by filtering or chem-ical absorption; an air-supplied respiratorprovides clean air from an outside source or froma tank.

18. Hazard-oriented medical surveillance programsuse biological indicators to monitor the absorp-tion of chemical agents by analyzing the levelsof the agent or its metabolite in the blood, urine,or expired air.

19. Substituting nontoxic or less toxic materials orequipment may be the least expensive and mostpositive way to control many occupational healthhazards. Often substitution results in consider-able savings for a company. As technology pro-gresses, more information about the toxicity ofmaterials becomes available and the list of pos-sible substitutes grows. Sometimes it is possibleto control or reduce a hazard simply by substi-tuting one form of a material for another, suchas substituting palletized or briquette forms ofa material to reduce a dust hazard. When exam-ining the possibility of substituting one materialfor another, industrial hygienists must be verycareful to ensure that a previously unforeseenhazard, such as a synergistic interaction betweenchemicals, does not occur as a result of the sub-stitution. In some cases, substitution may be

impossible or impractical, such as with processesinvolving ionizing radiation.

20. Some of the factors that influence the properdesign of exhaust ventilation systems includethe temperature of the process, the physical stateof the contaminant in question (dust, fume,smoke, mist, gas, or vapor), the way in whichthe contaminant is generated, the velocity anddirection in which the contaminant is releasedto the atmosphere, and the contaminant’s toxi-city. Designing local exhaust systems can be dif-ficult because hoods or pickup points must becorrectly shaped and located to capture con-taminants. The fan and ducts must draw the rightamount of air through each hood. The charac-teristics of a contaminant and how it is disperseddetermine which type of hood should be used.The hood should be located so that the contam-inant is moved away from the operator’s breath-ing zone. The type of contaminant, itsconcentration, and air pollution standards deter-mine the selection of an air cleaner.

ANSWERS—Quiz 2

1. b

2. a

3. a

4. a

5. b

6. c

7. a

8. d

9. b

10. a

11. b

12. The three basic steps that must be followed are:locate the contaminant source, establish the con-taminant’s path to the employee, and determinethe employee’s work pattern and use of protec-tive equipment.

18 • Methods of Control


13. Even though administrative controls can limitthe duration of individual exposures, they aredifficult to implement and maintain.

14. In a closed system, raw materials are brought toa processing site in sealed containers and emp-tied into storage tanks or containers. This typeof system keeps employee contact with materi-als to a minimum.

15. Locating one or more hazardous operationstogether in a separate building can reduce thenumber of workers exposed to the hazard andsimplify the necessary control measures.

16. Employees should be prohibited from using com-pressed air to remove particulates from clothingbecause this practice causes the particulates tobecome airborne and increases the risk ofemployee exposure.

17. Cradle-to-grave responsibility reflects the factthat producers of hazardous waste are perpetu-ally responsible for on-site and off-site damagesto the environment, as well as worker and com-munity health.

18. The difficulty involved in decontaminating theclothing and the endurance of the material usedcan determine whether disposable or reusableclothing should be chosen.

19. General ventilation can be used when smallquantities of air contaminants are being releasedinto the work environment at fairly uniform rates.It can also be used when there is sufficient dis-tance between a worker and the contaminantsource to allow sufficient air movement to dilutethe contaminant to safe levels. If only contami-nants of low toxicity are being used and if thereis no need to collect or filter contaminants beforethe exhaust air is discharged into the commu-nity environment, then general ventilation mayalso be implemented. In addition, general ven-tilation may be used if there is no possibility ofcorrosion or other damage to equipment fromthe diluted contaminants in the work environ-ment air. The exception to these criteria is usinggeneral ventilation for comfort control.

20. To help workers better understand the need forrespirators, employers can require that workersuse respirators only after every effort has been

made to eliminate the hazard using engineeringand administrative controls. Employers can alsohelp workers feel more comfortable with theequipment by fully explaining the hazards tothem and training them in the proper use andlimitations of the equipment. The employer canalso make sure the respirator fits the workeraccording to OSHA guidelines and that it is prop-erly maintained and cleaned after every use.


1. When Mayfield management begins designingits new facility, the use of personal protectiveequipment should be considered a last resort.Only if engineering or administrative controlsare not possible or if they are not sufficient toachieve acceptable limits of exposure should per-sonal protective equipment be required. The pri-mary disadvantage of personal protectiveequipment is that it does not eliminate the haz-ard from the workplace. If the equipment fails,the worker is immediately exposed to the haz-ard. A protective device may become ineffectivewithout the wearer’s knowledge, resulting inserious harm. The integrity and fit of a personalprotective device is vital to its effectiveness. Insome cases, personal protective equipment maybe appropriate during short exposures to haz-ardous contaminants, such as during nonrou-tine equipment maintenance or emergencyresponses to spills; however, if Mayfield man-agement intends to require the use of the equip-ment over long periods of time, employees maynot be as well protected from potential hazardsas management believes.

2. If Mayfield management implements engineer-ing and administrative controls and still requiresthe use of respiratory protection equipment inits new facility, there are several factors it mustconsider when selecting the equipment. It needsto identify the substance or substances for whichrespiratory protection is necessary and the tasksof the workers involved, as well as determinethe hazards of each substance and its significantphysical and chemical properties, particularlythe presence or absence of oil particles. Man-agement must also determine the maximum lev-els of air contamination expected, the probabilityof oxygen deficiency, and the condition of expo-sure. The period of time for which respiratoryprotection must be worn needs to be determined,



along with the capabilities, physical character-istics, and limitations essential to the safe use ofthe device. The facilities needed for maintenancemust be identified, and the location of the haz-ardous workspace in relation to the nearest areawith respirable-quality air must be determined.Management needs to consider occupationalexposure limits for the substance or substancesand respirator protection factors. In addition tothese considerations, OSHA requires thatemployers establish a respirator program when-ever the devices are used.

3. Wetting down dust is one of the simplest meth-ods of dust control. Wetting down floors beforesweeping to reduce the dispersion of dust is rec-ommended when better methods, such as vac-uum cleaning, cannot be used. The effectivenessof this method, however, depends on proper wet-ting. In some cases, a wetting agent, or surfac-tant, must be added to water. It is also importantto dispose of the wetted dust properly before itdries out and is redispersed. Wet methods havebeen used in various industries to reduce dusthazards. For example, forcing water through drillbits has reduced dust concentrations in rockdrilling operations. Many foundries clean cast-ings using water under high pressure in place ofsandblasting.

Chapter 19Local Exhaust VentilationANSWERS—Quiz 1

1. a

2. b

3. a

4. a

5. b

6. b

7. a

8. b

9. b

10. d

11. b

12. Dilution systems reduce the concentration ofcontaminants released into the workroom bymixing with air flowing through the room. Eithernatural or mechanically induced air movementcan be used to dilute contaminants. Local exhaustventilation systems capture or contain contam-inants at their source before they escape into theworkroom environment. The main advantage oflocal exhaust systems is that they remove con-taminants rather than just dilute them.

13. Hood selection is an area where the health andsafety professional can make a significant con-tribution since the keys to good hood selectioninclude the following: a knowledge of hood andairflow principles, an understanding of the plantprocesses, and a familiarity with employee workpatterns around each process. In many plants,the health and safety staff has the best overallunderstanding of these three areas.

14. A major limitation to the use of receiving hoodsis that gases, vapors, and the very small parti-cles that can be inhaled and retained in thehuman respiratory system do not travel very farin the air unless carried by moving air. Thismeans that receiving hoods are not very usefulfor health protection ventilation systems unlessthe process emits quantities of hot air or air withsufficient velocity to carry the respirable con-taminants into the hood.

15. Stainless steel and specialty plastics are usedwhere protection against corrosion is needed.

16. Major reasons for poor flow patterns are elbows,dampers, duct junctions, or other flow distur-bances near the fan.

17. Major removal techniques for gases and vaporsare absorption, adsorption, and oxidation.

18. A room or plant with insufficient makeup air issaid to be “air bound” or “air starved.”

19. Filter devices fall into two major categories: dis-posable and reusable. Filters may be made of

19 • Local Exhaust Ventilation


woven or felted (pressed) fabric, paper, or wovenmetal, depending on the application. They areavailable in a variety of configurations, such asmats, cartridges, bags, and envelopes. Filtershave the general advantage of being able to han-dle varying exhaust gas flow rates and particleloadings.

20. FSP = (SP inlet) + (SP outlet) – VP inletFSP = fan static pressure, inches of waterSP = static pressure, inches of waterVP = velocity pressure, inches of waterInlet/outlet = fan inlet and outlet

ANSWERS—Quiz 2

1. a

2. a

3. b

4. b

5. a

6. b

7. c

8. b

9. c

10. d

11. Wind direction and velocity are important factors.If there is a prevailing wind direction at the site, itshould help locate the stack on the downwind sideof the roof. However, the location of the stack andair intakes should recognize that wind will oftenblow from other than the prevailing direction. Alow wind speed allows the plume to rise due tothe discharge velocity and any thermal head. Aswind velocity increases, the first effect will be todecrease plume rise and the resulting dilution.

12. An insufficient quantity of makeup air may causepoor fan operation, inefficient combustion in fur-naces, drafts, and problems with slamming doorsin the work area.

13. The basic airflow concept in ventilation systems

is called the “equation of continuity,” whichexpresses mass balance as air flows through dif-ferent parts of the system. The equation of con-tinuity is expressed as Q = V x A, where Q =airflow, ft3/min; V = air velocity, ft/min; and A= area of airflow, ft2.

14. Pressure can be measured directly in inches ofwater using a U-tube manometer. Mechanical pres-sure gauges and electronic transducer units cali-brated in inches of water are also commonly used.

15. Air density is affected by the moisture contentand temperature of air as well as the altitudeabove sea level.

16. Smoke tubes are glass tubes containing a chem-ical that produces a chemical fume (smoke) asroom air is blown through the tube with a hand-operated bulb. They are useful for the followingtests: evaluating the capture range of hoods; iden-tifying drafts and other factors that can interferewith hood performance; demonstrating the cap-ture distance of hoods to workers so they canposition the hood or work item properly.

17. To measure static pressure in a duct, a small diam-eter hole is drilled through the duct wall. Theholes should be at least 7.5 duct diameters down-stream from any disturbance, such as an elbow.The end of a rubber tube attached to a U-tubemanometer or other pressure sensor is pressedagainst the duct over the hole and the static pres-sure is read in inches of water.

18. Air flowing through the ductwork meets resist-ance in the form of friction and turbulence.Straight duct lengths result in friction loss, whileelbows, junctions, air cleaners and other featurescause turbulence losses.

19. A typical local exhaust system consists of the fol-lowing elements. Hoods: any point where air isdrawn into the ventilation system to capture orcontrol contaminants. Ducts: the network of pip-ing that connects the hoods and other systemcomponents. Fan: the air moving device that pro-vides the energy to draw air and contaminantsinto the exhaust and through the ducts and othercomponents. Air cleaner: a device to remove air-borne materials that may be needed before theexhaust air is discharged into the communityenvironment.



20. Static pressure tests in a system that once oper-ated properly can help to identify the followingfan problems: loose fan belt or another driveproblem; material deposited on blades or bladeerosion/corrosion; centrifugal fan motor wiredincorrectly and therefore rotating backward. Typ-ical locations to measure static pressure includeHoods, entries into main ducts, on each side ofair cleaners, on each side of the fan, and at sev-eral points along long ducts.


1. A typical local exhaust system consists of the fol-lowing elements: hoods, ducts, fan, air cleaner.

2. The best type of hood for the task of spray paint-ing the iron handrails is an enclosure hood. Thissurrounds the contaminant source as much aspossible. Contaminants are kept inside the enclo-sure by air flowing in through openings in theenclosure. Student may mention a spray booth,which is a typical example of an enclosure hood.

3. Good room conditions are critical for properenclosure performance, including sufficientreplacement air, supply outlets located anddesigned to avoid drafts, and protection againstdisruptive air currents from open doors and foottraffic near the hoods.

4. The other types of hoods utilized in a local ven-tilation system include capturing hoods andreceiving hoods. There are also slot hoods andcanopy hoods.

5. The type of devices to consider depend prima-rily on the physical state of the contaminants,whether they are particulates or gases/vapors.

6. The student should choose a method for partic-ulate removal and defend the answer.

7. Makeup air should be supplied through aplanned system rather than through randominfiltration. The system should have the follow-ing features: supply rate should exceed exhaustrate by about 10 percent; air should flow fromcleaner areas to the plant; makeup air should beintroduced into the occupied zone of the plant;air should be heated in winter to about 65 F,makeup air inlets outside the building must belocated so that no contaminated air from nearby

exhaust stacks or chimneys is drawn into themakeup air system.

Chapter 20Dilution Ventilation ofIndustrial WorkplacesANSWERS—Quiz 1

1. b

2. a

3. b

4. d

5. Dilution occurs when contaminants released intothe workroom mix with air flowing through theroom. Either natural or mechanically induced airmovement can be used to dilute contaminants.

6. The amount of dilution airflow required dependson the physical properties of the contaminant(molecular weight and specific gravity [com-pared to water]), rate of contaminant release, thetarget airborne concentration, and the overallsafety factor.

7. The two main categories of fans are centrifugalfans and axial flow fans.

8. Smoke tubes are useful in identifying the air dis-tribution patterns in the work area, the move-ment of contaminants from discrete sources, thedirection of natural air movement, and problemssuch as short circuiting.

9. Tubeaxial fans are special propeller fans mountedinside a short duct section. The fan blades arespecially shaped to enable the fan to move airagainst low resistance.

10. Convective heat emitted by hot sources is called“sensible” heat.

11. The major disadvantage of dilution ventilationis that the inherent uncertainties that exist inmany of the design parameters require that largesafety factors be applied to assure that exposures

20 • Dilution Ventilation of Industrial Workplaces


are controlled. The uncertainties often result inlarge volumes of air being needed and may makedilution ventilation less cost-effective than localexhaust ventilation or another exposure controltechnique.

ANSWERS—Quiz 2

1. b

2. a

3. c

4. a

5. Air movement due to temperature differencescan be useful because hot processes heat the surrounding air, and the rising column ofwarm air will carry contaminants upward toroof vents.

6. The three different types of axial fans are pro-peller fans, tubeaxial fans, and vaneaxial fans.

7. Work in confined or enclosed spaces presentsspecial hazards including oxygen deficiency, toxiccontaminants, risk of engulfment by solid mate-rials, and the risk of being trapped by small pas-sageways.

8. Axial flow fans often used for dilution ventila-tion in enclosed spaces might exhibit a severedrop in airflow with added resistance to airflow.For each fan, the amount of air it can movedepends on the resistance or static pressure it isoperating against. In enclosed spaces, the extraresistance usually is due to either long lengthsof duct attached to the fan or too small openingsfor make-up air, which causes a slight negativeair pressure inside the space.

9. Dilution is often used to ventilate workspacessuch as tanks and utility vaults that are usuallyunoccupied but are occasionally entered forinspection, cleaning, maintenance, or othertasks.

10. When both employee exposure and fire/explo-sion prevention are considered for the same oper-ation, the dilution flow rate calculated usingEquation 1 almost always governs because theallowable airborne levels for breathing are signif-

icantly lower than the lower explosive limit (LEL).


1. Working in confined or enclosed spaces requiresextraordinary care. A safety plan for work inthese locations includes such features as pre-venting unauthorized entry, identifying and con-trolling the potential hazards, performing airmonitoring, providing ventilation, providing res-cue equipment and personnel, and trainingemployees.

2. “Short circuiting” can occur if the air movesfrom the inlet to the exhaust fan without dilut-ing contaminants where employees are work-ing. It may be necessary to block off some airinlets or take other steps to assure good air dis-tribution. In many applications, good air dis-tribution is easier to achieve if fresh air is blowninto the space using a flexible duct arrangementrather than using the fan to exhaust the space.The fresh air can be discharged into the areawhere people are working and will flow outavailable openings.

Chapter 21General Ventilation of Nonindustrial OccupanciesANSWERS—Quiz 1

1. a

2. b

3. a

4. b

5. a

6. b

7. b

8. c

9. d



10. a

11. c

12. The measurement represented by cfm OA/person is the number of cubic feet of fresh out-side air per minute per person.

13. It is important that supply air reach terminalvelocity before reaching building occupantsbecause at higher velocities it will cause draftsand, as a result, discomfort for occupants.

14. Mixing factor is the ratio of the amount of airrequired to dilute a contaminant to the idealamount of air that should reduce it.

15. Supply air distribution in the occupied zone isdetermined by the number, location, and type ofterminal devices, such as supply diffusers andreturn and exhaust grilles, that are used.

16. Simple measurements of supply air, outdoor air,return air, and occupied air space can indicateCO2 levels in room.

17. The relationship that forms the basis for esti-mating airflow using tracer gas methods is:change in tracer-gas concentration = amountintroduced – amount removed.

18. Microbiological growth can be minimized bykeeping filter systems well maintained, by con-ducting regular HVAC maintenance, by usinggood housekeeping practices, by locating airintakes in noncontaminated locations, and bykeeping all HVAC system components dry ordrained.

19. Good mixing can be achieved by providing andcorrectly positioning an adequate number of sup-ply and return registers. Registers should beplaced so that air is circulated to where peopleare located in the zone. Freestanding fans can beset up for people located in areas of poor mix-ing. This final approach is often cost-effectiveand acceptable to building occupants. A com-mon cause of poor mixing is furniture, whichcan change the movement of air. The partitionsused in offices, windows, and walls can also neg-atively affect airflow.

20. If the space above the ceiling is being used for

returning air, certain guidelines must be followed.First, any electrical wiring located there must bein conduit or coated with a special fire-resistantcovering. Plastic piping and plastic air registers,such as polyvinyl chloride, should not be usedbecause they produce smoke in the event of afire. The space above the ceiling should be keptclean and dry to reduce bioaerosol amplification.Fire walls that extend to the floor above must bebreached to allow the air to return to the air-han-dling unit. One way of doing this is to use back-draft dampers. Finally, ceiling tiles and accessdoors must be kept in place to ensure proper air-flow in the occupied space.

ANSWERS—Quiz 2

1. b

2. a

3. a

4. b

5. a

6. b

7. d

8. a

9. c

10. d

11. b

12. ASHRAE is the American Society of Heating,Refrigeration, and Air Conditioning Engineers,the primary North American association deal-ing with issues of indoor air quality. It has devel-oped several standards related to indoor airquality.

13. A single constant value system is less energy effi-cient because first it cools the air at the centralcooling coil, and then it reheats it at the final dis-tribution point.

14. The formula for calculating mixing efficiency isKm = Qactual / Qideal

21 • General Ventilation of Nonindustrial Occupancies


15. The three most important consensus standardsare ASHRAE 62 on Ventilation for IAQ, ASHRAE55 on Thermal Comfort, and ASHRAE 52 on AirFiltration.

16. The three phases are characterizing complaintsand gathering background data, checking per-formance of ventilation systems and their controls, and measuring carbon dioxide, tem-perature, and relative humidity.

17. The three tracer gas methods are the concentra-tion-decay method, the constant-emissionmethod, and the constant-concentration method.

18. If the air in a work space smells musty, there mightbe microbiological contamination in the ductwork.

19. To maintain temperature, a variable air volumesystem varies the amount of air delivered to aspace. As the temperature of a space decreasesto the desired level, the airflow diminishes. Sinceair volume and fan speed are linearly related, ifairflow is cut in half, then fan speed is cut in half,saving energy and money. Another factor in therelationship between air volume and fan speedis horsepower and speed, which have a third-power relationship. If speed is reduced by half,horsepower and the costs associated with it arereduced by eight. Using fan inlet dampers toreduce airflow also lowers costs, but not by thesame factor as reducing fan speed. By installingvariable-volume boxes at the distribution point,more zones can be supplied by a single fan. Asthe demand for air decreases, dampers at theboxes close, the fan slows, and energy is saved.If a building uses dual ducts for cool and warmair to maintain a minimum OA supply, mixingboxes can mix the air at the minimum flowrequired for temperature control and OA deliv-ery, allowing the fan to run at a lower rpm, sav-ing energy, and lowering costs.

20. Commissioning is used to identify, verify, anddocument the performance of a new HVAC sys-tem to ensure proper operation and compliancewith codes, standards, and design intentions. Acommissioning agent is often chosen by the build-ing owner, the architect, or the contractor to over-see construction and commissioning activities.These activities often involve tests and demon-strations to verify that a system is operating prop-erly. Troubleshooting and maintenance activities

also require testing the system.


1. The standard for thermal quality is ASHRAE55-1992: Thermal Environmental Conditions forHuman Occupancy. For a company to complywith the standard, 80–90 percent or more ofoccupants in an environment should find theenvironment thermally acceptable. The stan-dard attempts to predict what conditions of tem-perature, humidity, activity, clothing, airmovement, and radiant heat sources will sat-isfy 80–90 percent of people. At least 90 percentof people should be satisfied with any singleparameter, and satisfaction for all parameterscollectively should be 80 percent or more.ASHRAE 55-1992 does not cover other envi-ronmental factors such as air quality and con-taminants.

2. Temperatures that are too warm or too cold area common problem. Some of the reasons for thisproblem may be a misadjusted thermostat, toomuch or too little supply air, a malfunctioningor misplaced temperature sensor, or a defectiveor undersized HVAC system. In other cases, the supply air temperature setting may be toohigh or too low, the supply diffuser may beblowing directly on employees, cold air maynot mixing with the occupied air space, or thebuilding may be under negative pressure. If abuilding is under negative pressure, air couldinfiltrate at the building perimeter. Buildingpressures should be +0.03 to +0.05 in. wg. A thermometer, a velometer, and smoke tubescan be used to test the HVAC system for theseproblems.

A lack of air movement is a common problemwith older variable air volume systems. The prob-lem may arise when the system is set to deliverno air when cooling is not being requested. If anenvironment is stuffy or the air is stagnant, theproblem may be that the filters are overloaded,the dampers on the variable air volume systemmay be malfunctioning, some of the ductworkmay have disconnected from supply diffusers,or the ducts may be leaking. Nondelivery or lowdelivery of air to the space, restrictions in duct-work, inadequate delivery of outside air, andblockage from furniture, partitions, or other bar-riers may also lead to this problem.



3. To test stuffy or stagnant air, a thermometer, avelometer, smoke tubes, and a CO2 meter canbe used.

Chapter 22Respiratory ProtectionANSWERS—Quiz 1

1. b

2. b

3. a

4. b

5. a

6. c

7. a

8. d

9. b

10. d

11. d

12. A respirator must be National Institute for Occu-pational Safety and Health (NIOSH) approved.

13. Respirators can impose several physiologicalstresses ranging from very mild restriction ofbreathing to burdens of great weight and effort.The type of effects produced depends on the typeof respirator in use, the job, and the workplaceconditions. For this reason, a physician or otherlicensed health care professional must determinewhether or not an employee has any medical con-ditions that would preclude the use of respirators.

14. A user seal check is a test conducted by thewearer to determine if the respirator is properlyadjusted to the face. The procedures may varyslightly from one user to another due to differ-ences in construction and design. In general, theemployee is checking either for pressure or flowof air around the sealing surface.

15. Once a NIOSH-approved respirator has beenselected, the user should become acquainted withthe limitations of the device as set forth in theapproval. The approval will be void if the deviceis used in conditions beyond the limitations setby NIOSH or those established by the manufac-turer. The user should also guard against anyalteration being made to the device. All parts,filters, canisters, cartridges or anything else notspecifically intended to be used on the device byNIOSH or the manufacturer will void the exist-ing approval.

16. The most common starting carbon materials forrespirator cartridges are coconut and coal.

17. Service life of a respirator depends on qualityand amount of sorbent; packing uniformity anddensity; exposure conditions, including breath-ing rate of the wearer relative humidity, tem-perature, contaminant concentration, the affinityof the gas or vapor for the sorbent, and the pres-ence of other gases and vapors.

18. There is a typical wide variation of odor thres-hold in the general population. Other problemsexist: shift in odor threshold due to extended lowexposures, shifts due to simple colds and otherillnesses, and failure to recognize odors becauseof distraction of the workplace competing forworker attention. Given the variability amongpeople with respect to detection of odors anddifferences in measuring odor thresholds, a bet-ter practice is to establish cartridge change-outschedules.

19. A written respiratory protection program mustbe established when respiratory protection isneeded. It should include worksite-specific pro-cedures covering the following minimum pro-gram elements:• procedures for selection of proper respira-

tory-protective equipment including expo-sure assessment

• procedures for medical evaluation of respi-rator wearers

• procedures for fit testing of workers usingtight-fitting respirators

• procedures for proper respirator use duringroutine and reasonably foreseeable emer-gency situations

• procedures and schedules for cleaning, dis-infecting, storing, inspecting, repairing, and

22 • Respiratory Protection


discarding respirators• procedures to ensure adequate air quality,

quantity, and flow of breathing air for atmos-phere-supplying respirators

• procedures for training workers on respira-tor use and respiratory hazards

• procedures for regular program evaluation

20. Each respirator wearer must be able to demon-strate knowledge of at least the following:• why the respirator is necessary and how

improper fit, usage, or maintenance can com-promise the protective effect of the respirator

• what the limitations and capabilities of therespirator are

• how to use the respirator effectively in emer-gency situations, including situations inwhich the respirator malfunctions

• how to inspect, put on and remove, use, andcheck the seals of the respirator

• what the procedures are for maintenance andstorage of the respirator

• how to recognize medical signs and symp-toms that may limit or prevent the effectiveuse of respirators

• the general requirements of the OSHA res-piratory protection standard

ANSWERS—Quiz 2

1. a

2. a

3. a

4. a

5. b

6. b

7. c

8. a

9. a

10. c

11. d

12. As defined in the text, oil is any of numerous

mineral, vegetable, and synthetic substances andanimal and vegetable fats that are generally slip-pery, combustible, viscous, liquid, or liquefiableat room temperatures, and soluble in variousorganic solvents such as ether but not in water.

13. A combination type, full-facepiece pressure-demand airline respirator with auxiliary self-contained air supply OR a full-facepiecepressure-demand or other positive pressure self-contained breathing apparatus certified for aminimum service life of 30 minutes.

14. Respiratory-protective devices are being used toreduce exposure to aerosolized drugs andbioaerosols. This area presents many challengesincluding unknown safe levels of exposure forthese agents or respirator efficacy for bioaerosols.Acceptable airborne levels have not been estab-lished for many pharmaceutical drugs or poten-tially infectious aerosols. NIOSH approved orcertified respirators have not been tested againstbioaerosols such as TB.

15. The qualitative fit-test protocols consist of threesteps: threshold screening, respirator selection,and fit testing.

16. The procedure for cleaning respirators includesthe following steps: Remove filters, cartridges,or canisters. Disassemble facepieces. Discard orrepair any defective parts. Wash components inwarm water with a mild detergent or with acleaner recommended by the manufacturer. Astiff bristle brush may be used to facilitate dirtremoval. Rinse components in clean, warm waterand drain. When the cleaner used does not con-tain a disinfecting agent, respirator componentsshould be immersed for two minutes in an appro-priate solution as outlined in 29 CFR 1910.134.Rinse components thoroughly in clean, warmwater and drain. Dry by hand with a lint-freecloth. Reassemble and test to make sure it isworking properly.

17. Close off the exhalation valve and exhale gentlyinto the facepiece. The face fit is considered sat-isfactory if a slight positive pressure can be builtup inside the facepiece without any evidence ofoutward leakage of air at the seal.

18. CNP test exercises include: Normal breathingfor one minute followed by 10 seconds of held



breath; deep breathing for one minute followedby 10 seconds of held breath; turning head sideto side for one minute followed by 10 secondsof held breath; moving head up and down, etc.;reading aloud a prepared passage or countingbackward from 100; grimace for 15 seconds; bendat the waist and touch toes for 1 minute.

19. Atmosphere-supplying respirators fall into threegroups: air-line respirators, self-contained breath-ing apparatus, and combination air-line andSCBA. Air-line respirators deliver breathing airthrough a supply hose connected to the wearer’sfacepiece or head enclosure. The breathing air issupplied through the hose from either a com-pressor or compressed air cylinders. The SCBAprovides respiratory protection against gases,vapors, particles in an oxygen deficient atmos-phere. The wearer is independent of the sur-rounding atmosphere because the breathing gasis carried by the wearer. The combination unitsare air-line respirators with an auxiliary self-con-tained air-supply combined into a single device.

20. The steps for hazard determination are as follows:a. If the potential for an oxygen-deficient atmos-

phere exists, measure the oxygen content.b. Determine what contaminants may be pres-

ent in the workplace.c. Determine whether there are Threshold Limit

Values® (TLVs), Permissible Exposure Limits(PELs) or any other available exposure limits.

d. Determine if the IDLH concentration for thecontaminants is available.

e. Determine if there is a substance-specifichealth standard for the contaminants. If so,there may be specific respirators requiredthat will influence the selection process.

f. Determine the physical state of the contami-nant. If the contaminant is an aerosol, deter-mine whether the vapor pressure is significantat the maximum expected temperature of thework environment. In these situations it maybe possible to have a significant portion ofthe contaminant concentration in the vaporphase, requiring respiratory protection forboth the particle and vapor phase of the con-taminant.

g. Measure or estimate the concentration of thecontaminant.

h. Determine whether the contaminant can beabsorbed through the skin, cause skin sensi-tization, or be irritating to or corrosive to the

eyes or skin. Respirators that provide skinor eye protection or air-supplied suits maybe required in addition to providing protec-tion from the inhalation hazard.

i. For gases or vapors, determine if a knownodor, taste or irritation threshold existsbecause these may provide a secondary indi-cation for cartridge breakthrough.


1. A written respiratory protection program mustbe established when respiratory protection is needed. It should include worksite-specificprocedures covering the following minimumprogram elements:• procedures for selection of proper respira-

tory-protective equipment including expo-sure assessment

• procedures for medical evaluation of respi-rator wearers

• procedures for fit testing of workers usingtight-fitting respirators

• procedures for proper respirator use duringroutine and reasonably foreseeable emer-gency situations

• procedures and schedules for cleaning, dis-infecting, storing, inspecting, repairing, anddiscarding respirators

• procedures to ensure adequate air quality,quantity, and flow of breathing air for atmos-phere-supplying respirators

• procedures for training workers on respira-tor use and respiratory hazards

• procedures for regular program evaluation

2. Each respirator user must be able to demonstrateknowledge of the following:• why the respirator is necessary and how

improper fit, usage, or maintenance can com-promise the protective effect of the respirator

• what the limitations and capabilities of therespirator are

• how to use the respirator effectively in emer-gency situations, including situations inwhich the respirator malfunctions

• how to inspect, put on and remove, use, andcheck the seals of the respirator

• what the procedures are for maintenance andstorage of the respirator

• how to recognize medical signs and symp-toms that may limit or prevent the effectiveuse of respirators

22 • Respiratory Protection


• the general requirements of the OSHA res-piratory protection standard

3. Employees should have follow-up training atleast once a year.

4. The respirators must be properly stored in orderto protect them from dust, sunlight, excessiveheat, extreme cold, excessive moisture, dam-aging chemicals, and physical damage fromthings such a vibration and shock. Tool boxes,paint spray booths, and lockers are not appro-priate storage locations unless they are pro-tected from contamination, distortion, anddamage. In addition, emergency and rescue userespirators that are located in the work areamust be readily accessible. Their location mustbe clearly marked.

5. The program administrator’s responsibilitiesinclude the following:• conducting exposure assessments of the work

area prior to respirator selection and peri-odically during respirator use to ensure thatthe proper respirator is being used

• selecting the appropriate respirator that willprovide adequate protection from all con-taminants present or anticipated

• maintaining records as well as the writtenprocedures in a manner that documents the respirator program and allows for theevaluation of the program’s effectiveness

• evaluating the program’s effectivenessthrough ongoing surveillance of the program

Chapter 23The Industrial HygienistANSWERS—Quiz 1

1. a

2. b

3. b

4. b

5. d

6. Industrial hygienists must be competent in avariety of scientific fields—principally chem-istry, engineering, physics, toxicology, andbiology.

7. Some examples of health and safety activitiesthat may be performed by Occupational Healthand Safety Technologists are (1) safety inspec-tions; (2) industrial hygiene monitoring; (3)organizing and conducting health and safetytraining; and (4) investigating and maintainingrecords of occupational accidents, incidents,injuries, and illnesses.

8. In an industry setting, the industrial hygienemanager supervises the technical and supportstaff in a health and safety department; preparesbudgets and plans; is familiar with governmentagencies related to the operation; relates indus-trial hygiene operations to research and devel-opment, production, environmental, and otherdepartment or functions; and prepares appro-priate reports.

9. CIHs can earn certification maintenance pointsby working as an industrial hygienist; partici-pating in professional associations; attendingapproved meetings, seminars, and short courses;participating on technical committees; publish-ing in peer-reviewed journals; teaching, whennot part of their primary practice; and otherapproved activities.

10. In 2001, the American Board of Industrial intro-duced Certified Associate Industrial Hygienist(CAIH) program.

11. The Education and Research Centers providecontinuing education to occupational health andsafety professionals; combine medical, industrialhygiene, safety, and nursing training so that grad-uates are better able to work effectively in com-plex and diverse conditions; conduct research;and conduct regional consultation services.

12. The Accrediting Board of Engineering andTechnology has accredited master’s level pro-grams in industrial hygiene since 1985 andcurrently also accredits baccalaureate levelprograms.

13. The American Industrial Hygiene Associationdefines industrial hygiene as the anticipation,



recognition, evaluation, and control of environ-mental factors arising in or from the workplacethat may result in injury, illness, or impairment,or affect the well-being of workers and membersof the community.

14. Candidates for the OHST certification need fiveyears’ experience in occupational health orsafety activities that comprise at least 35 per-cent of job duties, must pass the OHST exami-nation, and complete certification maintenancerequirements every five years. Candidates maysubstitute college courses in health and safetyor an associate degree or higher in certain dis-ciplines for up to two years of the experiencerequirement.

ANSWERS—Quiz 2

1. a

2. a

3. a, c

4. c

5. a

6. In the civil service sector, the senior industrialhygienist differs from the industrial hygienist inreceiving more complex assignments and acting in place of the industrial hygiene super-visor when the supervisor is absent.

7. The training program for OSHA compliancesafety and health officers, instituted in 1992, isdesigned to provide a series of training coursessupported by on-the-job training and self-instruc-tional activities to ensure that compliance per-sonnel are able to apply technical informationand skills to their work.

8. Before attending the initial compliance courseat the OSHA Training Institute, each OSHACSHO must complete three self-study program:(1) the OSHAct, (2) Chapter III of the Field Inspec-tion Reference Manual, and (3) Integrated Man-agement Information Systems forms 1, 1A, 1B,and 1B-1H.

9. Once the training period is completed, CSHOsare required, at a minimum, to attend a techni-

23 • The Industrial Hygienist

53

cal course once every three years at the OSHATraining Institute.

10. The American Conference of Governmen-tal Industrial Hygienists sets Threshold Limit Values and updates these values annually.

11. The mission of the OSHA Office of Training andEducation is to provide a program to educateand train employers and employees in the recog-nition, avoidance, and prevention of unsafe andunhealthful working conditions and to improvethe skill and knowledge levels of personnelengaged in work relating the Occupational Safetyand Health Act of 1970.

12. Specific responsibilities of the OSHA Train-ing Institute include: (1) conducting programsof instruction for federal and state complianceofficers, state consultants, other federal agencypersonnel, and private sector employers,employees, and their representatives; and (2)participating in the development of courseoutlines, detailed lesson plans, and other edu-cational aids necessary to carry out trainingprograms.


1. For industrial hygiene trainees, assignments areselected and designed to orient the newemployee into the field of industrial hygiene, todetermine areas of interest and potential, torelieve experienced industrial hygienists ofdetailed and simple work, and to develop thetrainee’s knowledge and competence. Specificassignments are carried out under direct super-vision of a qualified industrial hygienist, includ-ing recognition and evaluation of hazards,identification of controls, calibration of equip-ment, collection of samples, and initial prepa-ration of reports.

2. Because compliance safety and health officersmust be familiar with general concepts of safetyand health, each CSHO is required to completecrossover training during the developmentalperiod—that is, CSHOs on the safety or construction track are encouraged to attend theintroduction to health course, while industrialhygienists are encouraged to attend the intro-duction to safety course.


Chapter 24The Safety ProfessionalANSWERS—Quiz 1

1. a

2. b

3. a

4. b

5. a

6. d

7. a

8. c

9. b

10. a

11. c

12. The ASP designation is awarded to safety pro-fessionals who have passed the Safety Funda-mentals Examination.

13. In addition to the government, the manufactur-ing, service, construction, insurance, and con-sulting sectors are the largest employers of safetyprofessionals.

14. The decision about who should assume full staffresponsibility for safety activities is influencedby the size of the organization and the nature ofthe hazards involved in its operation.

15. The “four Ms” and the “three Es” of safety areexamples of accident investigation techniques.

16. Job safety analysis is an important part ofemployee training because it details all the nec-essary safety elements related to a task and, there-fore, can be used by supervisors to trainemployees in safe work practices.

17. The five steps are hazard identification, hazard

elimination, hazard protection, maximum pos-sible loss, and loss retention.

18. Supervisors are key players in any safety andhealth program because they are responsible fortranslating management’s policies into actionand for promoting safe and healthful work prac-tices among employees. Supervisors’ attitudestoward safety and health will be reflected by theemployees in their departments.

19. One trend that has emerged in the developmentof safety professionals is related to the increas-ing emphasis on analyzing the loss potential ofthe activity with which the safety professionalis concerned. This type of analysis requiresgreater ability to predict where and how eventsresulting in injury and loss will occur and to findways of preventing such events. Another trendinvolves the increased development of factual,unbiased, and objective information about loss-producing problems and reasons for accidents.This information enables those who have ulti-mate decision-making responsibilities to makesound decisions. A third trend is connected tothe increasing use of the safety professional’shelp in developing safe products. Applying theprinciple of accident causation and control toproduct design or production has become moreimportant because of product liability cases;legal issues in the field of safety and health,including negligent design; and the impact saferproducts have on the overall safety and healthof the environment.

20. There are many advantages to having a thirdparty conduct a safety inspection. For example,an independent inspection team is less likely tobe biased in its findings and reports. The resultsof third-party inspections generally are directedto a higher level of decision-making body and,therefore, are more likely to be acted onpromptly. Safety inspections can be more con-venient if they are conducted by a third partysince they are not dependent on the schedule oforganization staff. In addition, the safety pro-fessionals contracted for third-party inspectionsusually have extensive experience in a givenindustry.

ANSWERS—Quiz 2

1. a



2. a

3. b

4. b

5. a

6. c

7. a

8. d

9. b

10. a

11. a

12. The BCSP is responsible for establishing the cri-teria for professional certification, acceptingapplications, evaluating the credentials of can-didates, and issuing certificates to those who metthe requirements.

13. A loss control representative helps companiesthat are insured or seeking to be insured iden-tify risks within their operations and reducethe possibility of accidents, fires, and otherlosses.

14. The purpose statement is often followed by gen-eral requirements and a procedure, including thedesignation of individuals or positions alongwith their special tasks or action steps.

15. The number of safety professionals and inspec-tors needed for adequate safety inspection activ-ities primarily depends on the size of a facility,the complexity of a facility, and the type of indus-try involved.

16. The benefits of conducting a job safety analysisinclude training individuals in safe, efficient pro-cedures, instructing new employees on safetyand health procedures, preparing for plannedsafety and health observations, providing “pre-job” instructions on irregular jobs, and review-ing procedures after accidents occur.

17. Spot-checking, reporting by repair control cen-ters, and auditing are the three basic elements of

a damage control program.

18. An individual can qualify for the title of Cer-tified Safety Professional by applying to theBoard of Certified Safety Professionals (BCSP),meeting an academic requirement, meeting aprofessional safety experience requirement,passing the Safety Fundamentals Examina-tion, and passing the Comprehensive PracticeExamination.

19. One reason for the increased number of full-time safety professionals is the OccupationalSafety and Health Act (OSHA), which waspassed in 1970. The act requires that certainsafety standards be met and maintained. A sec-ond reason is related to a better understandingof the safety professional’s services and func-tions. The safety professional responsible foradministering a safety program must be highlytrained and/or have many years of experiencein the safety field.

20. Management can use safety inspections to showemployees that it is concerned about their safetyand health. Every time a safety professional orinspection team evaluates a work area, man-agement demonstrates its interest in employ-ees’ safety and health. If unsafe conditions areidentified during an inspection, managementcan show employees its concern for their well-being and its interest in accident prevention bycorrecting the situation immediately. Inspectionscan also help to bolster employee interest inmanagement’s safety and health program andencourage employees to inspect their worksta-tions regularly. Regular inspections enable safetyprofessionals to become familiar with employ-ees and more readily gather information fromthem. By acting on employee suggestions, man-agement also demonstrates that to employeesthat their cooperation is vital and appreciated.


1. A good record-keeping system gives safetyprofessionals the means for doing an objec-tive evaluation of the magnitude of occupa-tional illness and accident problems. It alsoprovides them with a measurement of theoverall progress and effectiveness of the safetyand health program. It helps identify high-hazard units, facilities, or departments, and

24 • The Safety Professional


problem areas so that extra efforts can befocused on those areas, and provides the dataneeded to analyze accidents and illnesses andpinpoint specific circumstances of occurrence,which can then be addressed using specificcountermeasures. A good system promotesinterest in safety and health among supervi-sors by furnishing them with informationabout the accident and illness history of theirown departments. In addition, it providessupervisors and safety committees with hardfacts about safety and health problems so thatthey can focus their efforts, and helps meas-ure the effectiveness of individual counter-measures and determine whether specificprograms are doing the job that they weredesigned to do. An effective record-keepingsystem can help establish the need for, andthe content of, employee and managementtraining programs that can be tailored to fitthe particular needs of an organization orfacility.

2. Safety professionals at Jackson Metals can helpthe purchasing department by providing it withspecific information about safety and healthhazards that can eliminated by changes indesign or by having the manufacturer installguarding. They can also provide informationabout equipment, tools, and materials that cancause injuries if misused and offer specific infor-mation about health and fire hazards at thefacility’s worksites. Safety professionals canserve as resources for information on federaland state safety and health rules and regula-tions, and on the accident history of machines,equipment, or materials that are about to bereordered.

3. When the cost-effectiveness method is used, thecost of system changes made to increase safetyand health measures is compared with either thedecreased costs of fewer serious failures or withthe increased effectiveness of a system to per-form its task, in order to determine the relativevalue of these changes. Ultimately, all systemchanges have to be evaluated, and this methodmakes such comparisons explicit. Cost-effec-tiveness analysis is often used to help make deci-sions concerning the choice of one of severalsystems that can perform the same task.

Chapter 25The Occupational Medicine PhysicianANSWERS—Quiz 1

1. a

2. b

3. b

4. b

5. a

6. a

7. c

8. The student may list three of the following: useof anesthesia, aseptic technique, development ofdiagnostic instruments such as the stethoscopeand ophthalmoscope, tests such as x rays andelectrocardiograms, identification of organismscausing diseases such as cholera and tuberculo-sis and development of vaccines for use againstthem, combined with standardized population-based tests for vision, height/weight, and IQ.

9. Occupational medicine is now a sub-specialty ofthe medicine division or its own department inmany large medical group practices, hospitals,and universities. Freestanding occupationalhealth clinics, often combined with urgent-carecenters, offer another practice setting. Privateconsulting firms and international work are twogrowing sectors. Academic, occupational, andenvironmental health departments are anothermajor development.

10. All physicians graduating medical school after1984 are required to take a formal occupationalmedicine residency or fellowship program inorder to become eligible to take the OccupationalMedicine Board Examination. The program istwo years, usually after a full or partial residencyin another field such as internal medicine.



11. The student will name one of the following:American College of Occupational and Envi-ronmental Medicine, American Public HealthAssociation, or The National Association of Occu-pational Health Professionals.

12. The student may write an essay touching onsome of these key factors: Clinics may be a sin-gle entity or part of a chain of clinics located nearindustry and may provide a wide range of serv-ices from preplacement examinations and drugtesting to acute care for work-related injuries andillnesses. These clinics do not usually have thesame access to specialized services as hospitalor multi-specialty group practice programs. Oftenpractitioners in these clinics are required to see30 or more patients per day. Doctors in these clin-ics may not be specialists in the field, and maynot focus on injury illness treatment or pre-placement and surveillance examinations. Mostly,physicians working in these clinics will have lit-tle time or training to deal with complex healthand safety issues.

ANSWERS—Quiz 2

1. a

2. b

3. a

4. a

5. d

6. c

7. a

8. A resident’s program will include significantpublic health training in toxicology, epidemiol-ogy, statistics and a practicum year of clinical,research, and corporate placements, and publicsector agency rotations.

9. This career choice allows a wide range of prac-tice opportunities, including consulting withcompanies, local government agencies, andunions, performing medical surveillance andother examinations, acting as expert witnesses,

and doing epidemiological research. Frequently,these specialists have close working relation-ships with industrial hygienists, epidemiologists,toxicologists, and occupational health nurses, orhave them on staff.

10. The student may answer with any of the ques-tions or statements from the Occupational His-tory Form found on pages 770-771 of the text.Sample statement: List hobbies and active sportsyou do such as painting, woodworking, weld-ing, hairdressing, scuba diving, etc.

11. Preplacement examinations are an importantpart of ensuring a safe and healthy workforceas hiring those physically unable to do the jobtasks places an added burden and risk of injuryof coworkers. Preplacement evaluations canrange from a simple drug screen, a medical his-tory review by a registered nurse to a completemedical and occupational history and physicalexamination with functional capacity testingand other tests.

12. The corporate medical department is an area ofoccupational medical practice that is shrinkingdue to organizations downsizing and contract-ing out. Today’s corporate medical director willlikely be a consultant to human resources, help-ing provide quality assurance over the contractclinics which actually provide the services, andaiding in reviewing and negotiation with healthplans, medical review for difficult workers’ com-pensation cases, ADA and fitness for duty issues,development of protocols for exposures, andmedical surveillance.


1. For this question, the student should demon-strate a thorough understanding of the job oppor-tunities for an occupational medicine physicianby listing four of the following eight practice set-tings: corporate medical department, multispe-cialty group practice/hospital based programs,freestanding occupational health clinic, privateconsulting firms, academic occupational medi-cine departments, government agencies, inter-national occupational health consulting, unionoccupational health physician. The student willback up their list with specific job tasks for each

25 • The Occupational Medicine Physician


practice setting.

2. All physicians graduating medical school after1984 are required to take a formal occupationalmedicine residency or fellowship program inorder to become eligible to take the OccupationalMedicine Board Examination. The programencompasses two years, usually after a full orpartial residency in another field, such as inter-nal medicine.

3. The program content includes significant pub-lic health training in toxicology, epidemiology,and statistics, and a practicum year of clinicalresearch and corporate placements, and publicsector agency rotations.

4. The test is offered once a year by the AmericanBoard of Preventive Medicine. Approximately200-300 physicians take the test annually.

5. Students must relate their answer to the formfound in their textbook. This form questionsan employee regarding the exposure to poten-tial physical, chemical, biological and psy-chological hazards; the type of personalprotective equipment worn on the job; sec-ondary work experiences; hobbies and activ-ities he or she may participate in; problemswith fertility; and if he or she has ever hadany work-related experience believed to havebeen harmful.

Chapter 26The Occupational HealthNurseANSWERS—Quiz 1

1. b

2. a

3. a

4. b

5. c


58

6. Occupational health nurses provide care toemployees with the goal to prevent work-relatedinjury and illness, prevent disability, and helpworkers achieve and maintain the highest levelof health throughout their lives.

7. The Certified Occupational Health Nurse(COHN) and the Certified Occupational HealthNurse Specialist (COHN-S) credentials areawarded by the American Board of OccupationalHealth Nurses.

8. Certification is awarded based on specific edu-cational preparation, current occupational healthwork experience, evidence of continuing occu-pational health and safety education, and suc-cessful completion of an examination.

9. Additional academic preparation as a manager,nurse practitioner, or clinical nurse specialist inoccupational health nursing is available at thegraduate level at university-based, NIOSH-funded educational research centers.

10. In addition to the OHN, other members of theoccupational health services team might includean industrial hygienist, occupational medicinephysician, safety professional, ergonomist, phys-ical therapist, employee assistance program per-sonnel, and rehabilitation counselor.

11. Secondary prevention is the early detectionand treatment of disease and injury so thatprogression is slowed or complications arelimited.

12. The OHN is licensed as a registered nurse andhas both independent and dependent nursingfunctions, as authorized by the state businessand professions code. Advanced practice nurs-ing roles are also licensed, state by state, andinclude those registered nurses prepared at thegraduate degree level in the roles of clinical spe-cialist, nurse practitioner, nurse midwife, andnurse anesthetist.

13. The scope of occupational health servicesdepends on the following key industry variables:(1) company size and demographics of the workforce; (2) geographic distance of a health carefacility in the community; (3) type of industry;(4) hazard profile; (5) risk management and


health benefit philosophy of company, percentof insured work force; (6) economic resources;(7) self-insurance status for workers’ compen-sation and personal health care; and (8) organi-zational climate.

ANSWERS—Quiz 2

1. b

2. a

3. b

4. b

5. c

6. a, d

7. Approximately 45,000 adults in the United Statesdie annually of complications from influenza,pneumococcal infections, and hepatitis B, the pri-mary vaccine-preventable diseases affecting adults.

8. Examples of OHN employee training activitiesinclude: (1) education on how to adjust work-stations and work flow to prevent cumulativetrauma disorders; (2) education on the long-termeffects of noise and the need for hearing protec-tion; and (3) education and demonstration onproper lifting techniques and back-strengthen-ing techniques.

9. Approximately 33 percent of all private, nona-gricultural worksites with more than 50 employ-ees reported having an EAP resource for theiremployees.

10. Practice guidelines are clinical practice recom-mendations based on a critical review ofresearch/evidence. Some are focused on the diag-nosis of a specific health condition, and otherfocused on the clinical management of a healthcondition, with the key aim to standardize care.

11. Occupational health surveillance is the processof monitoring the health status of worker pop-ulations to gather data about the effects of work-place exposures and to use the data to preventillness or injury. The goal is early identificationof biological markers or endpoints that may sig-

nify exposure.

12. Case management is the timely coordination ofquality health services with the goal to decreasefragmentation of care, enhance the client’s qual-ity of life, and contain health care costs.

13. New health and safety regulations, mental healthissues in the workplace, the continued increasein cumulative trauma disorders, chronic illnessand the aging work force, the increased num-bers of women in the work force, and the chang-ing health care delivery structures are only a fewof the current health issues facing employers andoccupational health services.

14. A 1988 survey of Fortune 500 companies notedthe four most frequent occupational health nurs-ing activities were (1) supervising the provisionof nursing care for job-related emergency andminor illness episodes; (2) counseling employ-ees about health risks; (3) providing case man-agement for employees with workers’compensation claims; and (4) performing peri-odic health assessments.


1. Establishment of an ergonomics programrequires knowledge, skills, and abilities in thefollowing areas:• the diagnosis and treatment options for

repetitive strain injuries (clinical and pri-mary care)

• program design with policy and procedures(management)

• the ability to educate workers regarding neu-tral wrist position and postural issues (edu-cation/training; health promotion anddisease prevention)

• knowledge of ergonomics legislation and theAmericans with Disabilities Act (regula-tory/legislative)

• a team approach to analyze the workstationsand institute engineering controls (workforce, workplace, environmental/research,and professionalism).

2. An ergonomics program consists of managementcommitment, worksite analysis, hazard preven-tion and control, medical management, and train-ing and education.

26 • The Occupational Health Nurse


Chapter 27The Industrial Hygiene ProgramANSWERS—Quiz 1

1. a

2. a

3. b

4. b

5. a

6. d

7. d

8. c

9. a

10. The four stages of the Demming cycle are plan,do, check, and act.

11. The requirements and procedures outlined in awritten industrial hygiene program identify whatshould be done, how it should be done, whoshould do it, and how often.

12. Employees are organized into SEGs so that mon-itoring data can be applied to individuals whowere not directly monitored, but who might berepresented by the samples collected.

13. It is important to determine whether training cansolve a problem because training can addresslack of knowledge or incorrect knowledge, butit cannot effectively address lack of motivationor attention to the job.

14. The documentation must be maintained to showthat the program has been conducted in accor-dance with professional standards. The data col-lected may also be useful for future industrialhygiene or medical evaluations.

15. A health professional needs to have a good

understanding of what is manufactured, howit is manufactured, the potential safety andhealth hazards associated with these manufac-turing processes, and the physical requirementsof the various jobs to run an effective medicalprogram.

16. An organization’s purchasing department con-tributes to workplace safety by ensuring thatonly equipment and material approved by theorganization’s industrial hygiene, safety, envi-ronmental, or other responsible reviewing teamsare purchased. The department also promotesworkplace safety by obtaining material datasheets for all chemicals purchased.

17. An audit generally begins with an opening con-ference between the auditors and the manage-ment of the facility. During the conference, thepurpose, scope, and schedule of the audit arediscussed. The second step in the audit processinvolves gathering the information. Then theinformation is analyzed, key facts are confirmed,and any contradictions are resolved. After ana-lyzing the data, the auditors can usually gener-alize from specific situations to underlyingprogram deficiencies. They then present theirconclusions to the facility’s management and dis-cuss any remaining concerns. As the last step inthe process, a report is issued detailing the audi-tors’ findings.

18. A safety and health committee is a forum forsecuring cooperation and coordination fromamong those groups involved in a safety andhealth program. It also is a forum for exchang-ing ideas on safety and health issues. The com-mittee provides a means of involving employeesin the program safety and health program. It isresponsible for examining company safety andhealth issues and recommending changes in prac-tices or policies to management. It also conductsperiodic inspections of the workplace in addi-tion to evaluating and promoting interest in acompany’s safety and health program.

ANSWERS—Quiz 2

1. a

2. b

3. a



4. a

5. b

6. c

7. b

8. d

9. a

10. A goal is a desired outcome; an objective is a spe-cific activity or means of achieving a goal.

11. Workers that should be included in SEGs arethose who can be expected to have the same orsimilar exposure profiles to an environmentalagent based on the information gathered duringworkplace, work force, and agent characteriza-tions.

12. It is important to have a written procedure forsampling methods to ensure that samples arecollected in a proper, consistent, and profes-sionally accepted manner.

13. Health and safety committees and employee sug-gestion programs address employee involve-ment in decisions that affect worker health andsafety.

14. Auditors prepare for an audit by researching therequirements of a program’s components anddeveloping a plan to evaluate compliance. Check-lists, including extensive lists for each programcomponent, frequently serve to guide the datacollection.

15. An agent characterization involves compiling aninventory of environmental agents and includesa description of their potential adverse healtheffects.

16. The remaining six components that an industrialhygiene program should address are: hazardrecognition, hazard evaluation and exposureassessment, hazard control, employee trainingand involvement, program evaluation, and doc-umentation.

17. The first step involves making a subjective deter-mination as to whether the exposure to each envi-

ronmental agent listed for an exposure group islow, moderate, high, or very high relative to anexposure limit. The determination should bemade using factors such as the frequency andduration of exposure, estimated exposure level,and the severity of the health effects that couldresult from exposure. The second step in theprocess is to monitor the exposures and comparethe results against established exposure limits.The potential exposures that were rated veryhigh in the first step should be monitored first,while those that were rated low should be mon-itored last.

18. A supervisor’s responsibilities begin with set-ting a good example for employees and ensur-ing that safety and health rules are followed. Asupervisor must also ensure that employeesreceive training in potential safety and healthhazards and the control measures associated withtheir jobs. Ensuring that all necessary personalprotective equipment is provided and used andthat employees receive all required medicalexaminations are two additional responsibilities.A supervisor also has the responsibility to reportpromptly any operation or condition that mightpresent a hazard to employees.


1. The policy statement included in an industrialhygiene program publicly states the following:• the company’s commitment to employee

health and safety• the purpose of the program and the require-

ment for the active participation of allemployees

• the importance that management places onthe health and safety of its employees, as wellas management’s commitment to occupa-tional safety and health. (This commitmentis demonstrated by management placinghealth and safety at the same level of author-ity and accountability as production.)

• the company’s pledge to comply with all fed-eral, state, and local occupational safety andhealth regulations

• a call for active leadership, direct participa-tion, and the enthusiastic support of the entireorganization

2. Training is an effective control measure becauseit provides employees with real-time under-

27 • The Industrial Hygiene Program


standing of the potential hazards in the work-place and the corrective actions to be taken toprevent adverse effects.

3. Training methods depend on the type and degreeof the hazard, both of which should be deter-mined by an industrial hygienist.

4. In terms of requirements for training programs,OSHA recommends beginning by determiningwhether training can solve a problem. Trainingcan address lack of knowledge or incorrectknowledge, but cannot effectively address lackof motivation or attention to the job. It is alsoimportant to determine what is expected of anemployee and what kind of training is neededto accomplish this goal. It may help to consultwith the safety and health committee to hear itssuggestions for tailoring training to employees’needs. OSHA also recommends that clear, meas-urable instructional objectives written in spe-cific, action-oriented language be establishedbefore training begins. Training sessions shouldsimulate the actual job as closely as possibleusing participatory techniques such as hands-on work or case studies. The training should bepresented so that its organization and meaningare clear to employees. An effective programenables employees to demonstrate they haveacquired the necessary skills and knowledge.To ensure a training program is accomplishingits goals, OSHA requires that an evaluation bedone using student surveys, a supervisor’sobservations, or tests. If any aspect of a trainingprogram is unsuccessful, it needs to be revisedand those steps of the process repeated. To doc-ument how training needs have been met, OSHAsuggests using attendance records, course out-lines, lesson plans, student exams, and handoutmaterials.

Chapter 28Government RegulationsANSWERS—Quiz 1

1. a

2. a

3. b

4. a

5. b

6. d

7. a

8. b

9. d

10. c

11. b

12. Each employer shall furnish to each employee aplace of employment free from recognized haz-ards that cause or are likely to cause death orserious physical harm to the employee. Eachemployer shall comply with occupational safetyand health standards under the act. Eachemployee shall comply with occupational safetyand health standards and all rules, regulations,and orders issued pursuant to the act that areapplicable to his or her own actions and conduct.

13. The significance of the General Duty Provisionis that it authorizes the enforcement of a recog-nized industry safety or health standard whenidentified hazards are not covered by an exist-ing OSHA standard.

14. As provided for under section 18 of OSHAct, astate agency can assert jurisdiction under statelaw over safety and health if a state plan thatmeets the criteria set forth in section 18(c) is sub-mitted for approval by federal OSHA. As of thisdate, there are 23 approved state plans as wellas plans for Puerto Rico and the Virgin Islands.

15. The OSHAstandards consist of the following cat-egories: design standards, performance standards,vertical standards, and horizontal standards.

16. In 1976, OSHA defined the action level as typi-cally one-half the permissible exposure limit(PEL). Where exposures reach or exceed theaction level, additional requirements apply,including medical surveillance and a full air-monitoring program. Exposures to an airborneconcentration above the PEL trigger still furtherrequirements, including reduction of exposures



to or below the PEL by means of engineeringcontrols supplemented by work practice con-trols, use of specified respirators, and use of otherappropriate protective clothing and equipment.

17. The essential elements of a visit are preinspec-tion planning, opening conference, walk-throughinspection, sample collection, and closing con-ference.

18. A failure to abate situation exists when an itemof equipment or condition previously cited hasnever been brought into compliance and is notedat a later inspection.

19. The standard requires the following employeetraining measures:• explanation of the requirements of the

standard• identification of workplace operations where

hazardous chemicals are present• knowledge of the methods and observations

used to detect the presence of hazardousworkplace chemicals.

• assessment of the physical and health haz-ards of those chemicals

• warnings about hazards associated withchemicals in unlabeled pipes.

• descriptions of hazards associated with non-routine tasks

• details about the measures employees cantake to protect themselves against these haz-ards, including specific procedures.

• explanation of the labeling system• instructions on location and use of material

safety data sheets (MSDSs)• details on the availability and location of

the hazardous material inventory, MSDSs,and other written hazard communicationsmaterial.

20. The student should demonstrate a completeunderstanding of the role of the secretary of laboras outlined in the text. In summary, the OSHActgrants the secretary of labor the authority topromulgate, modify, and revoke safety and healthstandards; to conduct inspections and investi-gations and to issue citations, including proposedpenalties; to require employers to keep recordsof safety and health data; to petition the courtsto restrain imminent danger situations; and toapprove or reject plans from states proposing toassume jurisdiction from federal OSHAover their

private sector industries and state and local gov-ernments. The act authorizes the secretary tohave the Department of Labor train personnelin the duties related to their responsibilities underthe act and, in consultation with the U.S. Depart-ment of Health and Human services, to providetraining and education to employers and employ-ees. The secretary may grant funds to the statesto identify program needs and plan develop-ment, experiments, demonstrations, adminis-tration/operation of programs. Along with theDepartment of Health and Human Services, thesecretary of labor is charged with developingand maintaining a statistics program for occu-pational safety and health

ANSWERS—Quiz 2

1. b

2. b

3. b

4. a

5. a

6. c

7. a

8. c

9. d

10. b

11. c

12. It has been determined that three key dutiesshould be triggered when an action level isreached—exposure measurement, medical sur-veillance, and employee training. All three actionsare considered necessary by OSHA beforeemployee exposures reach the PEL.

13. Getting Results and Improving Performance(GRIP) focuses on achieving the following objectives:• reducing injuries, illnesses, death• increasing assistance provided to employers

and employees in providing safe and health-

28 • Government Regulations


ful workplaces• addressing problems before they may result

in workplace incidents• concentrating limited resources on the worst

hazards and workplaces• delivering better public service in a more

prompt and efficient manner• creating a better place for OSHA field staff

to work by building joint labor-managementconsensus

14. The student will most likely name the broad cat-egories of Monitoring Program, Medical Pro-gram, Education and Training Programs, andRecord-Keeping Program. Also give credit ifhe/she names specifics of these programs, i.e.,even if a student does not specifically say“Record-Keeping Program,” give credit if theymention something about how long records aremaintained or the accessibility of records toemployees.

15. Regulated areas must be clearly identified andknown to affected employees. Regulated areasshall be demarcated and segregated from the restof the workplace in a manner that minimizes thenumber of people who will be exposed to a chem-ical. The regulated area designations must bemaintained according to the criteria of the stan-dard. Daily rosters of authorized personnel enter-ing and leaving the area must be maintained.Summaries of such rosters are acceptable.

16. The student must name one of the followingcriteria:• The violations resulted in a worker fatality,

a worksite catastrophe, or a large number ofillnesses.

• The violations resulted in persistently highrates of worker injuries or illnesses.

• The employer has an extensive history ofprior violations of the act.

• The employer has intentionally disregardedits safety and health responsibilities.

• The employer’s conduct taken as a wholeamounts to clear bad faith in the perform-ance of his or her duties under the act.

• The employer has committed a large num-ber of violations so as to undermine signifi-cantly the effectiveness of any safety andhealth program in place.

17. An “other than serious violation” is one that has

a direct relationship to job safety and health butprobably would not cause death or serious phys-ical harm, such as a tripping hazard.

18. The Comprehensive Environmental Response,Compensation, and Liability Act (CERCLA)established the Superfund Program to handleemergencies at uncontrolled waste sites, to cleanup the sites, and to deal with related problems.

19. The student essay should summarize the fol-lowing information:• The main purpose of the walk-through

inspection is to identify potential workplacehealth hazards.

• During the walk-through, the industrialhygienist becomes familiar with workprocesses, collects information on chemicaland physical agents, and observes workers’activities.

• The industrial hygienist obtains informationconcerning raw materials used, intermedi-ates (if any), and final products.

• The hygienist requests a list of raw materi-als received at the loading dock.

• He also checks for hazardous physical agentspresent in the facility such as noise and exces-sive heat.

• He observes work activity throughout thefacility, but concentrates particularly onpotential health hazard areas.

• The approximate number of workers in eacharea is written on the sketch of the facility.

• The hygienist observes and records the gen-eral mobility of the workers and indicateswhether they are engaged in stationary ortransient activities.

• Existing engineering controls are marked.• Ventilation measurements are made at strate-

gic locations.• The hygienist keeps alert for any imminent

dangers.• Photographs and employee interviews are

encouraged.

20. The student should demonstrate an understand-ing of the broad scope of the OSHAct, touchingupon many of the following key provisions:• Assure, insofar as possible, that every

employee has safe and healthful workingconditions.

• Require employers to maintain accuraterecords of exposures to potentially toxic mate-



rials or harmful physical agents that arerequired, under the various safety and healthstandards, to be monitored or measured, andinform employees of the monitoring results.

• Provide for employee walkaround or inter-view of employees during the inspectionprocess.

• Provide procedures for investigating allegedviolations at the request of any employee oremployee representative, issuing citations,and assessing monetary penalties againstemployers.

• Empower the secretary of labor (through theOccupational Safety and Health Adminis-tration) to issue safety and health regulationsand standards that have the force and effectof law.

• Provide for establishment of new rules andregulations for new or anticipated hazardsto health and safety.

• Establish a National Institute for OccupationalSafety and Health (NIOSH), with the sameright of entry as OSHA representatives, toundertake health studies of alleged hazardousconditions and to develop criteria to supportrevisions of health standards or recommen-dations to OSHA for new health standards.

• Provide up to 50/50 funding with states thatwish to establish state programs that are atleast as effective as the federal program inproviding safe and healthful employment.

• Provide funds to state governments and otherentities for the purpose of authorizing andenabling them to conduct onsite consulta-tions for employers upon request.


1. The essential elements of a visit are preinspec-tion planning, opening conference, walk-throughinspection, sample collection, and closing con-ference.

2. Ms. Greenley would like to examine the facil-ity’s monitoring program, medical program,education and training programs, and record-

keeping programs.

3. The main purpose of the walk-through inspec-tion is to identify potential workplace health haz-ards; during the walk-through, the industrialhygienist becomes familiar with work processes,collects information on chemical and physical

agents, and observes workers’ activities. Theindustrial hygienist obtains information con-cerning raw materials used, intermediates (ifany), and final products. The hygienist requestsa list of raw materials received at the loadingdock. He also checks for hazardous physicalagents present in the facility such as noise andexcessive heat. He observes work activitythroughout the facility, but concentrates partic-ularly on potential health hazard areas. Theapproximate number of workers in each area iswritten on the sketch of the facility. The hygien-ist observes and records the general mobility ofthe workers and indicates whether they areengaged in stationary or transient activities. Exist-ing engineering controls are marked. Ventilationmeasurements are made at strategic locations.The hygienist keeps alert for any imminent dan-gers. Photographs and employee interviews areencouraged.

4. An industrial hygienist makes sure that regu-lated areas meet the following standards: Theymust be clearly identified and known to affectedemployees. Regulated areas shall be demarcatedand segregated from the rest of the workplacein a manner that minimizes the number of peo-ple who will be exposed to a chemical. The reg-ulated area designations must be maintainedaccording to the criteria of the standard. Dailyrosters of authorized personnel entering andleaving the area must be maintained. Summariesof such rosters are acceptable.

5. Types of violations include the following: immi-nent danger, serious violations, and willful vio-lations. In addition, there are criminal/willfulviolations, repeated violations, egregious con-ditions, and other-than-serious violations.

Chapter 29History of the FederalOccupational Safety andHealth AdministrationANSWERS—Quiz 1

1. b

28 • Government Regulations


2. a

3. b

4. a

5. a

6. d

7. b

8. c

9. The Occupational Safety and Health Act wassigned into law on December 29, 1970.

10. The disagreement over the proposed creationof OSHA centered on the extent of the powersto be assigned to the secretary of labor. Gener-ally, Democrats favored a strong role for the secretary, while the Republicans felt the con-centration would not be balanced with a strongrole.

11. Two elements in the statutory structure aredesigned to constitute an incentive to employ-ers to abate hazards: (1) sanctions are imposedwhen violations are disclosed at the first inspec-tion, and (2) no advance notice is given of work-place inspections.

12. The Bureau of Labor Statistics in the Departmentof Labor was assigned the responsibility of devel-oping an effective program of collection, com-pilation, can analysis of occupational safety andhealth statistics.

13. George C. Guenther was the first head of OSHA,its first assistant secretary.

14. An administrative structure was established for OSHA that included 10 regional offices and49 area offices staffed with compliance officersresponsible for conducting workplace inspections.

15. In 1969, several factors contributed to a consen-sus that federal occupational legislation wasneeded, including: (1) the workers’ compensa-tion system had not provided sufficient finan-cial incentives for employers to improveworkplace safety and health; (2) the accident ratewas rising; (3) illness in the workplace was a seri-

ous and rapidly increasing problem; and (4) stateefforts had proven inadequate.

16. To the extent that a hazard is not covered by astandard, the employer must comply with thegeneral duty obligation to provide a workplacefree from recognized hazards likely to causedeath or serious physical harm.”

17. OSHA’s first priority for inspection (after deal-ing with imminent dangers) is to investigateworkplaces where fatalities or catastrophes haveoccurred; the second priority is response toemployee complaints; the third priority is thespecial hazard elimination programs, whichinclude target industries and health hazards; andthe fourth priority, to the extent resources areavailable, is to conduct inspections of all otherworkplaces to show that the act’s obligations areapplicable to all.

ANSWERS—Quiz 2

1. b

2. a

3. a

4. b

5. a

6. d

7. Many of OSHA’s start-up standards were takenfrom standards issued by the American NationalStandards Institute (ANSI) and the National FireProtection Association (NFPA).

8. The right of employees or their representativesto request an inspection and their right to par-ticipate in the physical inspection of the work-place are foremost in the OSHA program.

9. The source of Congress’s influence over OSHAis its ultimate authority to amend the OSHActand, on a continuing basis, its power to controlthe agency’s annual appropriations.

10. A lead standard issued in 1978 contained a novelprovision requiring employers to transferemployees who were at excess risk from lead



exposure to lower-exposure jobs, and to main-tain their wage levels and seniority, generally fora period of up to 18 months.

11. Under the OSHAct, criminal penalties can beimposed for willful violations of a standard caus-ing the death of an employee.

12. Two overriding issues have been argued andresolved in standards proceedings: (1) the PELnecessary to protect employees, and (2) the eco-nomic and technological feasibility of reachingthat level through engineering controls.

13. In September 1974, OSHA received a complaintfrom a former employee of Life Sciences Prod-ucts Company, a chemical manufacturer, alleg-ing his exposure to pesticide fumes and dust.Because of the complaint’s informality, the OSHAoffice did not conduct an inspection. About 10months later, it became known that Life Sciencesemployees had been massively exposed toKepone, a pesticide that caused serious illnessin seven employees. It was also discovered thatpervasive ecological damage had been causedby the company’s unlawful disposal of Keponein the James river. Soon thereafter OSHA revisedits field instructions on inspections.

14. OSHA started the “egregious” penalty policy in1986, when the agency directed its field staff to

impose separate penalties for different instancesof violations if the inspection disclosed flagrantand widespread violations at the workplace. Pre-viously, separate instances of the same violationwold be grouped together as one violation.


1. For several years there had been a significantincrease in injuries caused by repetitive motionand other ergonomic-related factors, cuttingacross a wide spectrum of industries and work-places.

2. In 1990, OSHA responded to this new and seri-ous problem by establishing a special-emphasisenforcement program for ergonomics. To coor-dinate and support agency activities in theergonomics area, OSHA established a new Officeof Ergonomic Support in its Technical SupportDirectorate.

3. In 1992, OSHA published an advance notice ofproposed rulemaking, requesting data and com-ments on ergonomic hazards in the workplacerelated to the absence of ergonomic safety andhealth programs. Although OSHA has stated thatpublication of an ergonomics standard is a highpriority, the future of the rulemaking is unclearin view of strong employer opposition and con-troversy in Congress over the standard.

29 • History of the Federal Occupational Safety and Health Administration


fundamentals of industrial hygiene

Documents

national safety councilchapter

safety professional

federal occupational

additional safety measures

industrial noise

industrial hygienist

industrial toxicology

industrial hygiene program