osceola district schools laboratory hygiene program

Osceola District SchoolsLaboratory Hygiene Program

Module 4: Standard Work

Practices

The Basis of Safe Science

Safety – Student Safety is always the highest priority.Awareness – Be aware of Florida Statutes regarding the use of

science equipment.Foreseeability – Anticipate potential safety problems and plan

interventions and solutions.Establish Rules – Post and discuss clear rules for science activities.Supervision – Carefully supervise students during hands-on

activities and labs.Caution – Inform students of any precautions that are necessary

for student safety.Instruction – Teach and review proper safety rules and techniques.Equipment - Use appropriate and safe science equipment.Notice -- Take note of potential hazards and take reasonable

precautions.Chemicals -- Use only approved chemicals and store them

correctly.Environment -- Maintain a safe and orderly classroom.

Generic Generic Standard Operating Standard Operating ProceduresProcedures

Common sense do’s and don’ts

Examples: Ordering, distribution

& storage of chemicals

Safe use of chemicals

SAFETY CHECKLISTGeneral Safety Practices

What follows is a safety checklist. It represents a good guide for the processes involved in teaching science. It is not intended to be all-inclusive and there may be other safety issues that must be addressed as well.

Do not leave hazardous materials exposed or in places where they may be knocked over.

Review material safety data sheets (MSDS) when you receive a chemical and before using one..

Before carrying out an activity or experiment, familiarize yourself with its possible hazards.

Do not use alcohol burners. Be familiar with the District’s Emergency Mgt. Plan

and your school’s emergency action guides, evacuation procedures, and the location and use of firefighting equipment.


At start of science activity, instruct students about potential hazards and the precautions to be taken.

Limit size of a group of students working on an experiment to a number that can perform the experiment safely.

Plan enough time for an experiment or activity and for securing the chemicals and by-products.

Clean up and properly store equipment and materials when finished.

Students are likely to use this time to horseplay if not supervised!


Instruct students to never taste, or place in their mouths, any substance used in a science laboratory setting. They should develop the habit of washing their hands after every experiment in which they handle chemicals.

Instruct students not to touch classroom substances or material without first obtaining instructions from you.

Instruct students to report all accidents or injuries, however small, to you immediately. Be sure they know that there is no penalty for this.


Instruct students that it is unsafe to touch their faces, mouths, eyes, and other parts of their bodies while working with plants, animals, or chemical substances and afterwards, until they have washed their hands and cleaned their nails.


SAFETY CHECKLISTWorking with Chemicals

Wear appropriate protective clothing and insist the students do the same. Safety is an attitude more than it is a behavior.

Teach students not to mix chemicals just to see what happens. Explain that the lesson is only an experiment to them, you know the result because of previous work.

With elementary students, use vinegar or lemon juice for activities calling for an acid. More one substitution in another module.

Place broken glass in a separate disposal container with rigid puncture resistant sides and bottom.

Warn students not to drink from glassware used in science experiments.

Use thermometers filled with alcohol, not mercury.

Allow no food in the laboratory. Make sure refrigerators for chemicals and compounds have signs indicating No Food to be Stored.

SAFETY CHECKLIST Glassware

Whenever possible, substitute plastic. Don’t heat hard glass test tubes from the

bottom. They should be tipped slightly, but not in the direction of another student.

Tell students to report sharp edges on mirrors or glassware.

Keep a whisk broom and dust pan available for sweeping up broken glass.


Remove sharp edges from mirrors, prisms, and glass plates by grinding or by having edges covered with nail polish.

When inserting glass tubing into a rubber stopper: End should be fire polished; do not insert tubing

with a jagged end Aim tubing away from palm of hand Lubricate glass with glycerin or petroleum jelly Do not let students do this!!!


Use of Electrical Devices

Do not grasp any electrical device that has just been used – it may be hot.

Do not “short circuit” dry cells or storage batteries. Connecting wire will become hot, can cause serious burns or fires. Store dry cell batteries in containers by themselves rather than in “junk” drawers.

Pull on plugs, not on power cords. Plug devices into nearest outlet; try not use extension cords.

Use of Optics and Light

Never permit students to look into direct or reflected laser beams.

Set up experiments at a low height, making it more difficult to look into the beam.

Holograms should be viewed with a beam greatly expanded (use firmly mounted diverging lens).

Beam intensity can be reduced by: Using beam splitters or spreaders Using neutral density filters Working at greater distances from the laser

Observing the Sun

NEVER look directly at the sun with unaided eye or camera, telescope, binoculars, etc.

NEVER use an eyepiece filter. To observe the sun, you CAN safely use:

Projected pinhole image. Projected telescope image Telescope with full aperture solar filter (1/100,000

intensity or less)

Use of Tools and Machines

If using hand tools, have a suitable work space and storage facility for tools.

Use tools only for the purpose for which they were designed.

Ties, gloves, or loose clothing should not be worn when using power tools.

Avoid contact with heating elements or moving parts.

Ensure that guards are in place and that appropriate protective clothing (eyes) is used.

Good Practice

Lesson plans: In any lesson plan that includes an activity, list all safety precautions and announcements.

Safety contracts: a good start to any school science class is to have the students and parents become aware of the standards of behavior and any consequences

Document! Get a signature.

Chemical and HazardousAcquisition and Storage

CHEMICAL ACQUISITION

One of the most important control measures that science teachers can participate in is the management of chemical inventories. Careful attention to which chemicals are purchased, their potential good (learning) vs. their potential risk (incompatibility and health hazard) must always be evaluated. Chemical inventories should precisely match lesson plans. We will look at four area of concern: Procurement, Receipt, Distribution and Storage.


Procurement - Chemicals for lab work or demonstrations must be ordered through the school. Acquiring chemicals through other means, including self-purchase by instructors or donations is strictly prohibited unless specifically approved by the Health and safety Specialist. Highly toxic chemicals of any nature cannot be used.

Purchase the minimum amount of chemicals necessary for short term use and distribution. If possible, purchase chemicals in class-size quantities only. Plan to use for no more than one or two years. Do not stockpile chemicals! It is expensive and can be hazardous.

Some chemicals are not allowed:

Some chemicals are not allowed:

For obvious reasons certain chemicals are restricted from use on school property. A list of these is available here and in the Chemical Hygiene Plan in Appendix B.

Teachers are sometimes tempted to enhance the laboratory experience by bringing in their own supplies or individual chemicals. According to the NSTA this is one of the leading problems associated with accidents in the laboratory classroom.

For obvious reasons certain chemicals are restricted from use on school property. A list of these is available here and in the Chemical Hygiene Plan in Appendix B.

Teachers are sometimes tempted to enhance the laboratory experience by bringing in their own supplies or individual chemicals. According to the NSTA this is one of the leading problems associated with accidents in the laboratory classroom.

Prohibited Chemicals

Some chemicals are not allowed

Some chemicals are not allowed

There are several reasons beyond the District prohibition for not bringing in your own chemicals and supplies. The first is that your lab classroom is already set up to accommodate lessons under the direction of the science department. The next reason is that when a teacher brings in these materials he or she accepts almost all of the liability for anything that happens should something go wrong. The teachers protection requires that he or she act as a reasonable person. Violating policy take the teacher out of that arena.


Receipt - Before a hazardous chemical is received review the Material Safety Data Sheets (MSDS) and any other manufacturer information for proper handling, storage and disposal. Make this information available to all staff involved in shipping, receiving, storage and distribution. Preferably, all hazardous chemicals should be received in a central location within the department and inspected.


If a chemical is received without a manufacturer’s label do not accept it. Send it back! Manufacturer labels must have the name and address of the manufacturer, name of the chemical, and hazard information. By law, it is the manufacturer’s responsibility to label containers.

Never open a reagent package until the label has been read and completely understood.

The receiving party should initial all incoming chemicals with the date received.


Distribution - Clearly label all chemical storage areas. Use labels or placards on access doors to warn occupants and emergency response personnel such as fire fighters or paramedics.

An inventory of all chemicals must be maintained and readily available for review.


Storage - Properly store flammable liquids in small quantities in containers with a provision for bonding vessels when the liquid is transferred.

Students should have limited access to the chemical storage area. Although chemical inventories aid in assuring that all the chemicals that are supposed to be present students have been known to substitute materials for desired chemicals. It is best to restrict their access.

Your chemicals should be stored in an area that is well illuminated and well vented to the outside. You should not store favorite or “special” stocks of chemicals in other places in the classroom or school.


The storage room should be kept at moderate temperature all year. Sunlight may also be an issue. The MSDS will tell you if the chemical is sensitive to ultraviolet light. If so the chemical should be inside a closed cabinet unless it is being used.

Avoid storing chemicals or empty containers on the floor in the storage room. A clear floor space makes it less likely that someone will have to reach to acquire a container.

Heavy containers, particularly those of glass should be store on lower shelves to avoid pulling them down on yourself and to promote proper lifting technique.

Stored chemicals must have specific information on the label.

When receiving chemicals and when returning them to the storage room, teacher should make it a habit to examine the container label. All labels must have the following information.1. The chemical name2. The supplier’s name3. The date of purchase or mix4. The concentration5. The associated hazards pertinent to the chemical

Chemical Storage

Storage

When storing chemicals that are some basic procedures that should be followed in order to limit the risk of cross contamination, amount of material involved in an accident and the severity of any accidents. They are:

Be sure to provide enough shelf space so there is no crowding.

Insist on bars or lips on the edge of shelving as it helps prevent items from falling off.

Store chemicals, large glassware, and heavy articles on lower shelves.

Storage Keep all toxic substances behind a locked door.

(Suggestion: use the same precautions you would with a small child in the home.)

Keep materials in easily handled containers appropriate and approved for the materials they contain. When using portable containers remember that they must be labeled appropriately. Federal and State regulations require this labeling.

Consider the volatility of chemicals when storing them. Flammables must be kept away from ignition sources. Light sensitive chemicals must be in opaque or amber glass containers and should be store in closed cabinets.

Storage

Know which of your chemicals react to others (MSDS) and store reacting materials away from each other.

Don’t store anything you don’t need. If you don’t have a plan for it this session, don’t keep it. Dispose of it properly.

Store only what you are going to use – a year’s supply is recommended.

For a one-shot activity, have on hand only what is needed for the activity.

Labeling When storing chemicals you should label both

storage area and individual items so that they can be easily replaced after use. This will ensure that you can find them when needed.

Use caution in accepting old material from another class, school, teacher, or other source. Many materials are altered by age and you have no idea how this material was treated or stored.

Every material you have in the classroom (other than household chemicals with the labels in place) must have a Material Safety Data Sheet (MSDS) in room and in school office. You must be able to locate these rapidly.

Labeling Chemicals should be identified by common name,

scientific name, formula, precautions, and antidote. Appropriately dispose of substances if they have

lost their labels. Always store acids, bases, and salts in separate

areas and advise students to do the same when these materials are being used.

Develop a system for moving materials from storage to classroom areas (e.g., rolling carts). Many chemical releases occur during movement.

Mercury – Under no circumstances is any form of MERCURY allowed in the School District of Osceola

RECORDS AND REPORTS

Accident reports – Accident reports serve several purposes. One is to provide the District and your school with viral information as to how to prevent accidents in the future. Another is to meet insurance, worker’s compensation and regulatory requirements. Accident investigation is therefore very important.

In the event of an accident the school administrator or the District may decide to involve the District’s Health and Safety personnel. This extra set of eyes can act as an neutral party that can offer accident investigation and prevention.

Student should be encouraged to report accidents and should understand that there is no punishment involved.

RECORDS AND REPORTS

Chemical inventory list – Each science area which uses chemicals is required to maintain a chemical inventory. This inventory should describe the material, amounts in stock and the location of the material.

The District will provide an inventory tool that allows the teacher to record this information in a uniform and consistent manner using the District intranet or other similar process.

RECORDS AND REPORTS

Training reports – Certain training, such as this and other modules, are required by the District or other body. You should ensure that this training is recorded and that you are up to date on any certifications that are required by you position.

Medical reports – Federal regulations discussed in Module 2 require that anyone working with chemicals have a baseline physical and an additional physical upon exposure to certain substances. These medical reports are required to be kept by the SDOC for thirty (30) years in most cases.

RECORDS AND REPORTS

Records of exposure – any time a teacher, staff member, student or visitor is exposed to any chemical where there is reason to believe that a health hazard exists an exposure report must be written.

When we talk about exposure, it means that you have come into contact with a chemical and it has gotten into your body. In order to understand whether or not this is serious it is important to evaluate the kind of exposure involved.

RECORDS AND REPORTS

You can be exposed to a chemical in three main ways:

Inhalation — breathing in chemical vapors or air with a chemical in it

Ingestion — swallowing a chemical in food, soil, or water

Dermal — a chemical soaking through your skin (the MSDS will identify dermal hazards).

Being close to a chemical source does not necessarily mean you have been exposed to the chemical. And even if you are exposed to a chemical, it may not make you sick.

RECORDS AND REPORTS A chemical can harm you ONLY if you can say yes to

ALL of the questions below: Source – Was there a chemical present with which

you could have contact? Exposure Route - Did you breathe in the chemical,

swallow it, or touch it? Toxicity - Is this chemical toxic by this particular

exposure route? Dose - Did enough of the chemical get into your

body to cause harm? Duration & Frequency - Did exposure happen

long enough and often enough to cause harm?

RECORDS AND REPORTS

Each of these questions must be considered to determine if a harmful exposure has occurred. For example, if someone swallowed some elemental mercury it may not have a serious effect because elemental mercury is not well-absorbed by the digestive system. However, if the mercury sat in a warm, enclosed room, turned into vapor, and you breathed in the vapor, it wouldn't take a large amount to make you sick since mercury vapor is absorbed readily through the lungs.

RECORDS AND REPORTS

Any exposure should be evaluated by asking the questions just covered. If there is any suspicion that an exposure has occurred it is better to report it than ignore it. Use the District’s exposure report process to record the event and your supervisor will take the steps necessary to process the event.

Proper Disposal of Chemicals

Teachers have two roles in handling chemicals at work. The first is obvious, teaching our students the joys and practice of science. Beyond that however teachers are also the stewards of the District’s property and the safety of the environment.

For this reason, proper disposal of chemicals and chemical waste is very important. Teachers and administrator must help protect the environment through accurate reporting of chemical inventories and proper disposal of unwanted chemicals and waste.

Proper Disposal of Chemicals - Guidelines

Laboratory wastes or discarded chemicals should be reused or recycled whenever possible. Before discarding unwanted chemicals, contact other schools to determine if your over-stock could be used at their location. Overstock is defined as unopened uncontaminated product.

The science teacher must ensure that laboratory chemicals are disposed of in compliance with appropriate regulations and in a manner which minimizes damage to people and to the environment.

Be aware of and respect expiration dates. Expired or obsolete chemicals must be properly disposed.


Chemicals must be disposed of properly via instructions obtained from the manufacturer or through a licensed chemical removal company. You should develop a plan for disposal procedures for chemicals before they are purchased.

First, prepare a complete list of chemicals of which you wish to dispose. Place the MSDS(s) with the chemical(s) to be disposed. Classify each of the chemicals on the disposal list into a hazardous or non-hazardous waste chemical.


Unlabeled bottles (a special problem) must be identified to the extent that they can be classified as hazardous or non-hazardous wastes. (Some laboratories will analyze a mystery bottle for a fee.)

When in doubt concerning the disposal of unwanted or waste chemicals, contact the School District of Osceola County Health and Safety Division of Risk & Benefits Management.


CAUTION – The “Flinn Scientific, Inc.” catalog describes ways to “treat” waste chemicals. The only disposal “treatment” permitted in the District is the evaporation of water, and the neutralization of small quantities of acids and bases. When in doubt concerning the disposal of unwanted or waste chemicals, contact the School District of Osceola County Health and Safety Division of Risk & Benefits Management. The Health and Safety Specialist will arrange for the disposal of unwanted chemicals through a licensed chemical removal company.

The Basis of Safe Science is how we prepare ourselves, our classroom laboratory and our students for the science experience. Teachers must make every effort to control the elements that go into the making of a safe science environment. Safety is not just about being careful, it is about being methodical in the way we practice science and how we acquire, store, handle and dispose of the chemicals we use to explore science with our students.

Summary

End of Module

Go to the QuizReferences

ASE (1996) Safeguards in the School Laboratory (10th ed..), Hatfield: ASE.

Borrows, P. (1992) ‘Safety in secondary schools’, in Hull, R. (ed.), ASE Secondary Science Teachers’ Handbook, Hemel Hempstead: Simon & Shuster. (This highlights the common accidents in labs most of which involve chemicals in the eye or mouth or on the body; and describes five ‘main danger areas’ such as burns from alcohol fires and alkali metal explosions.) More recently Borrows has written: ‘Safety in science education’, in Ratcliffe, M. (ed.) (1998).

DfEE (1996) Safety in Science Education, London: HMSO. Everett, K. and Jenkins, E. (1991) A Safety Handbook for

Science Teachers, London: John Murray. The MSDS Hyperglossary at

http://www.ilpi.com/msds/ref/index.html

References

29 CFR 1910.1450 – OSHA’s Laboratory Standard also known as Title 29 of the Code of Federal Regulations Part 1910, Subpart Z, Section 1450

Action Level – a concentration designated in 29 CFR part 1910 for a specific substance, calculated as an eight hour-time weighted average (TWA), which initiates certain required activities such as exposure monitoring and medical surveillance. Action levels are generally set at one half the PEL but the action level may vary from standard to standard.

Acute toxicity – is the ability of a chemical to cause a harmful effect such as damage to a target organ or death after a single exposure or an exposure of short duration.

American Conference of Governmental Industrial Hygienists (ACGIH) – a non-profit organization consisting of a community of professionals advancing worker health and safety through education and the development and dissemination of scientific and technical knowledge. The ACGIH develops and publishes recommended occupational exposure limits each year called TLVs for hundreds of chemicals, physical agents and biological exposure indices.

American National Standard Institute (ANSI) – a non-profit organization that administers and coordinates the US voluntary standardization and conformity assessment system.

Biological Materials – Biological or biohazardous materials include all infectious organisms (bacteria, fungi, parasites, viruses, etc.) that can cause disease in humans or cause significant environmental or agricultural impact.

Carcinogen - A substance capable of causing cancer. Carcinogens are chronically toxic substances; that is, they cause damage after repeated or long-duration exposure, and their effects may become evident only after a long latency period.

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CAS # - Chemical Abstracts Number – a unique number assigned to a chemical by the Chemical Abstracts Service.

CFR – Code of Federal Regulations – contains the listings of all US Federal regulations. The CFR, compiled by the Office of the Federal Register, is divided into 50 titles, which cover broad areas subject to Federal regulation.

Chemical Hygiene Officer – an employee designated by the employer who is qualified by training or experience to provide technical guidance in the development and implementation of the provisions of the Chemical Hygiene Plan. Note that these duties can be in addition to the other job functions the employee performs in the laboratory.

Chemical Hygiene Plan (CHP) – a plan that addresses specific hazards in the laboratory and is required by OSHA’s Laboratory Standard

Corrosive – a substance which causes damage to skin, eyes or other parts of the body on contact. Concentrated acids are examples of corrosive substances.

Embryotoxin – a substance which retards the growth or affects the development of an unborn child up to and including deformities and death. Mercury compounds, certain heavy metals, aflatoxin, formamide, and radiation are known embryotoxins.

Explosive – means a chemical that causes a sudden, almost instantaneous release of pressure, gas and heat when subjected to sudden shock, pressure, or high temperature.

Face velocity – the average velocity of air drawn through the face of a chemical fume hood and generally calculated as the total volumetric exhaust flow rate for the hood divided by the area of the open face, less an adjustment for hood air leakage.

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Irritant – a chemical which may cause reversible inflammation upon contact. Laboratory -Any facility where the "laboratory use of potentially hazardous chemicals"

occurs. It is a room where relatively small quantities of potentially hazardous chemicals are used during scientific experimentation.

Flammable – means a chemical that falls into one of the following categories: aerosol flammable is an aerosol that when tested by the method in 16 CFR 1500.45,

yields a flame protection exceeding 18 inches at full valve opening, or a flashback (a flame extending back to the valve) at any degree of valve opening

gas flammable is a gas that at ambient temperature and pressure, forms a flammable mixture with air at a concentration of 13% by volume or less or a gas that at ambient temperature and pressure, forms a range of flammable mixtures with air wider than 12% by volume, regardless of the lower limit.

liquid flammable means any liquid having a flashpoint below 100°F (37.8°C), except any mixture having components with flashpoints of 100°C or higher, the total of which make up 99 percent or more of the total volume of the mixture.

solid flammable means a solid, other than a blasting agent or explosive as defined in 1910.109(a), that is liable to cause fire through friction, absorption of moisture, spontaneous chemical change, or retained heat from manufacturing or processing, or which can be ignited readily and when ignited burns so vigorously and persistently as to create a serious hazard. A chemical will be considered a flammable solid if, when tested by the method described in 16 CFR 1500.44, it ignites and burns with a self-sustained flame at a rate greater than one-tenth of an inch per second along its major axis.

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FM 200 – a Halon replacement extinguishing agent which is a chemical blend (heptafluoropropane), stored as a liquid within the agent cylinder similar to that of Halon-type cylinders. It will not corrode sensitive electronic equipment, and contains no particulates or oily residues. In fact, it leaves very little residue and is a quite popular extinguishing agent in use today for the protection of computer rooms.

Fume Hood - a laboratory device, enclosed on five sides with a moveable sash or fixed partial enclosure on the remaining side; constructed and maintained to draw air from the laboratory and to prevent or minimize the escape of air contaminants into the laboratory; and allows chemical manipulations to be conducted in the enclosure without insertion of any portion of the employee’s body other than hands and arms.

Hazardous chemical – the OSHA definition is a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees. The term "health hazard" includes chemicals which are carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous membranes.

Hazard Communication Standard – 29 CFR 1910.1200 - was first enacted on November 25, 1983, by the OSHA. It was later modified with minor changes and technical amendments to take effect March 11, 1994. The purpose of the standard is to ensure that chemical hazards in the workplace are identified and evaluated, and that information concerning these hazards is communicated through MSDSs and labels. This standard is also known as the Right-to-Know Law.

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HEPA - high efficiency particulate air filter – is a filter that is manufactured, tested and certified to meet applicable construction and efficiency standards for high-efficiency filters. The filters are manufactured from an ultra-fine glass-fiber medium designed to capture microscopic particles that can easily pass through most other filters by a combination of diffusion, interception, and inertial impaction.

Health Hazard - means a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees.

Inergen - It is an inert gas used for fire extinguishment. It is a mixture of three naturally occurring atmospheric gases: 52% nitrogen, 40% argon, and 8% CO2. The Inergen gas curtails and extinguishes fire by lowering the oxygen content beneath the level that supports combustion. But it should be noted that due to the CO2 present in Inergen, the brain continues to receive the same amount of oxygen in an Inergen atmosphere as it would in a normal atmosphere, for reasonable periods of time.

Laboratory Scale - Working with substances in which the containers used for reactions, transfers, and other handling of substances are designed to be easily and safely manipulated by one person.

Laboratory Standard – a standard (29 CFR 1910.1450) issued by OSHA addressing occupational exposures to hazardous chemicals in the laboratory. All laboratories must comply with this standard.

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Laboratory use of Potentially Hazardous Chemicals - the handling or use of such chemicals in which all of the following conditions are met:

1) Use of laboratory scale. 2) Multiple chemical procedures or chemicals used. 3) Protective laboratory practices and equipment are available and in common

use to minimize the potential for student/teacher exposure to hazardous chemicals. LC50 or lethal concentration 50 – this is a measure of toxicity which corresponds

to the concentration in air that kills 50% of the test population. Note that most estimates of human toxicity are based on animal studies, which may or may not relate to human toxicity.

LD50 or lethal dose 50 – this is a measure of toxicity which corresponds to the dose required to kill 50% of the test population. Note that most estimates of human toxicity are based on animal studies, which may or may not relate to human toxicity. The LD50 is usually measured in milligrams of the material per kilogram of body weight of the test animal. To estimate a lethal dose for a human based on animal tests, the LD50 must be multiplied by the weight of an average person.

Material Safety Data Sheets (MSDS) – is a well-established document for disseminating health and safety information about chemical products to employees, customers, emergency responders, and the public. Information contained in the MSDS includes potential health, safety, and environmental hazards, safe handling practices, and applicable regulatory information.

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National Fire Protection Association (NFPA) private non-profit organization, is the leading authoritative source of technical background, data, and consumer advice on fire protection, problems and prevention

Organic peroxide - an organic compound that contains the bivalent -OO- structure and which may be considered to be a structural derivative of hydrogen peroxide where one or both of the hydrogen atoms has been replaced by an organic radical. Peroxides can be very dangerous materials and may be shock and thermal sensitive. They are also strong oxidizers. OSHA – Occupational Safety & Health Administration http://www.osha.gov is part of the US Department of Labor. Its mission is to save lives, prevent injuries and protect the health of America's workers.

Particularly hazardous substance – is defined by OSHA in the Laboratory Standard and includes “select carcinogens” (strongly indicative of causing cancer in humans), reproductive toxins, and substances which have a high degree of acute toxicity.

Permissible exposure limit (PEL) - which represents the maximum amount or concentration of a substance that a worker may be exposed to under OSHA regulations. There are ceiling values (at no time should this value be exceeded) and 8-hour time weighted averages (an average value of exposure over the course of an 8 hour work shift)

Personal Protective Equipment (PPE) – is all clothing and other work accessories designed to create a barrier against workplace hazards. Examples include safety goggles, respirators, lab coats, etc.

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Pyrophoric – a pyrophoric material is one that ignites spontaneously in air and is derived from the Greek word meaning “fire-bearing”. Many of these materials will also react vigorously with water or high humidity and ignite upon contact.

Physical Hazard – A hazard exhibited by certain chemicals due to their physical properties. These chemicals fall into the following classes: combustible liquids, compressed gases, explosives, flammable liquids or solids, organic peroxide, oxidizers, pyrophoric materials, and unstable (reactive) or water reactive materials.

Reproductive toxins – per OSHA any chemical that affects the reproductive chemicals which affect the reproductive capabilities including chromosomal damage/mutations and effects on fetuses (teratogenesis).

Select carcinogens – per OSHA any substance that meets one of the following criteria: regulated by OSHA as a carcinogen listed under the category, “known to be carcinogens” in the Annual Report on Carcinogens

published in the latest edition by the National Toxicology Program (NTP) listed under Group 1 (“carcinogenic to humans”) by the International Agency for Research on

Cancer Monographs (IARC) listed in either Group 2A or 2B by IARC or under the category, “reasonably anticipated to be

carcinogens” by NTP and causes statistically significant tumor incidence in experimental animals in accordance with any of the following criteria: after inhalation exposure of 6-7 hours per day, 5 days per week, for a significant portion of a lifetime to dosages of less than 10 mg/m3, after repeated skin application of less than 300 mg/kg of body weight per week, or after oral dosages of less than 50 mg/kg of body weight per day.

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Sensitizer – a chemical which may lead to the development of allergic reactions after repeated exposure.

Short term exposure limit (STEL) - which is the concentration employees can be exposed to continuously for a short period of time without suffering from irritation, chronic or irreversible tissue damage, or narcosis of sufficient degree to increase the likelihood of accidental injury, impair self-rescue or materially reduce work efficiency.

Standard Operating Procedures (SOP) – is a document that describes the operations, analyses, or actions that are commonly accepted methods or the laboratory prescribed procedures for performing certain routine or repetitive tasks.

Target Organ - indicate which bodily organs are most likely to be affected by exposure to a substance. Certain chemicals may bio-concentrate in the liver while other target the brain.

Threshold Limit Values (TLV) – are airborne concentrations devised by the ACGIH that represent conditions under which it is believed that nearly all workers may be exposed day after day with no adverse effect. TLVs are advisory exposure guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies when they exist. There are three different types of TLV's: Time Weighted Average (TLV-TWA), Short Term Exposure Limit (TLV-STEL) and Ceiling (TLV-C).

Tort Law – is the law of liability and negligence. It involves that plaintiff who allegedly has been wronged and the defendant who is claimed to have perpetrated the injustice. Tort law deals with issues of property and personal injury law. Mass tort is the process of suing a major defendant on behalf of a large number of plaintiffs. Law suits involving drugs such as Vioxx are examples.

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Toxicity Characteristic Leaching Procedure (TCLP) – is a procedure (Method 1311) performed on a sample within the laboratory to determine whether or not a waste is considered hazardous. A sample is extracted with a buffered acid and the resulting extraction fluid or leachate approximates the fluid that would leach from the sample if it were in a landfill.

Toxicity Characteristic (TC) – regulatory limits established for 39 compounds. If a waste analyzed via the TCLP procedure detects any of these compounds above the regulatory limits then the waste is said to exhibit the toxicity characteristic.

Water Reactive - these substances are dangerous when wet because they undergo a chemical reaction with water. This reaction may release a gas that is either flammable or presents a toxic health hazard. In addition, the heat generated when water contacts such materials is often enough for the item to spontaneously combust or explode.

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Prohibited Chemicals Aniline A4 Aniline hydrochloride B4 Antimony trichloride B4 Arsenic A4 Arsenic trioxide A4 Asbestos A4 Benzene A4 Benzoyl peroxide A4 Chlorine A3 Chloretone A4 Chloroform A4

Chromium B4 Chromium oxide B4 Chromium potassium

sulfate B4 Chromium trioxide A4 Colchicine A3 Dichloroethane/

Ethylene dichloride A3 p-Dioxane A4 Hydrobromic acid A4 Hydrofluoric acid A4 Hydrogen A3

Lithium metal A4 Mercury A4 Mercuric chloride A4 Nicotine B4 Phenol A4 Phosphorus, red, white A4 Phosphorus pentoxide A4 Picric acid A4 Potassium metal A4 Pyridine B4

Pyrogallic acid/pyrogallolB4

Sodium arsenateA4

Sodium arseniteA4

Sodium azideA4

Sodium cyanideA4

Sodium dichromate B4


KEY:A= Extremely HazardousB=Hazardous C=Somewhat Hazardous D=Relatively Non-Hazardous

1-Very Common (76-100%)2-Common (51-75%) 3- Infrequent (26-50%) 4- Very Infrequent (0-25%)

Sodium metal A3 Sodium nitrite B4 Stannic chloride B4 Stearic acidD4 Sudan IV B4 Thiourea B4 O-Toluidine B3-B4 Uranyl nitrate B4 Urethane B4 Benzone/Benzoin A4 Bromine A3

Cadmium chloride A4

Cadmium metal B4 Cadmium sulfate A4 Chromic acid/chromium

trioxide A4 Cyclohexane B4 Formaldehyde A4 Formalin B4 Hematoxylin B4 Hydrogen sulfide B4 Hydroquinone B4


Iso-amyl (or pentyl) alcohol B4

Mercuric iodide Red Powder A4

Mercuric nitrate Cryst. A4 Mercuric oxide A4 Mercuric sulfate A4 Mercurous chloride A4 Mercurous nitrate A3 Methyl ethyl ketone B4 Pentane B4 1-Phenyl-2-thiourea B4

Phenylthiocarbamide B4

Potassium periodateB4

Sodium chlorateB4

TrichloroethyleneB4

UrethaneB4

XyleneB4


KEY:A= Extremely HazardousB=Hazardous C=Somewhat Hazardous D=Relatively Non-Hazardous

1-Very Common (76-100%)2-Common (51-75%) 3- Infrequent (26-50%) 4- Very Infrequent (0-25%)

Quiz Four

1. Every science facility that stores chemicals must have an inventory which includes:

a. The manufacturer of the chemical.

b. The date is was received or mixed.

c. The storage location of the chemical in the facility.

d. All of the above.

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Quiz Four

2. As a matter of good practice and upon receipt of a chemical the teacher should:

a. Store the chemical only after it has “settled.”

b. Store the chemical in a temporary holding area.

c. Review the MSDS for the chemical.

d. Remove the factory label and replace it with a local label.


Quiz Four

3. Teachers should instruct students about the hazards of a science activity…

a. At the beginning of the school year.

b. Prior to any testing as a matter of course.

c. After the activity begins.

d. Before the start of any activity


Quiz Four

4. The teacher should use caution during after-activity cleanup since students are prone to:

a. Become involved in horseplay if not supervised.

b. Become contaminated with cleaning supplies.

c. Shy away from responsibility.

d. Work too hard before the entire class is finished.

e. All of the above.


Quiz Four

5. One very important habit that students should develop is:a. Doing homework prior to leaving school.

b. Testing materials using as many senses as possible.

c. Hand washing

d. Reclaiming waste chemicals following experiments.

e. Bringing chemicals in from home.


Quiz Four

6. Students should understand that reporting injuries is important and that:

a. There is no penalty for this.

b. Any violations in safe practices will be dealt with.

c. This is true no matter how small they are.

d. A and C are correct.

e. All of the above are correct.


Quiz Four

7. Before drinking from laboratory glassware the students must:

a. Make certain that the container is spotless.

b. Wash the container in hot water.

c. Use a litmus test to be certain it is safe.

d. Students must never drink from lab glassware.


Quiz Four

8. Before inserting glass tubing into a stopper the teacher should make certain that:a. The end of the tubing has been fire

polished.b. The tubing is aimed away from the palm of the

hand.c. The end is lubricated with glycerin of

petroleum jellyd. It is not a student performing this task.

e. All of the above


Quiz Four

9. When unplugging an electrical appliance the teacher should be careful to:

a. Pull on the plug rather than the cord .

b. Place one hand on the outlet to prevent removal.

c. Cover extension cords with rugs to prevent tripping.

d. None of the above.


Quiz Four

10. Before using any tools in the facility with moving parts the teacher must ensure:

a. That all guards are in place.

b. Power is left on all the time.

c. That every appliance is on a dedicated circuit.

d. That heating elements are cool to the touch.

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That’s Right!

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You have Finished Module Four.

Good Job!