Chemical Risk Chemical Risk ManagementManagement

Session 3Laboratory Safety Training

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Toxic effects of Laboratory Toxic effects of Laboratory ChemicalsChemicals

In order to minimize the hazards associated with chemicals used in the laboratory the researcher must investigate many sources of information to safely design the experiment. There are many ways to do this. The starting point should be with a review of the MSDS.

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Hazard CommunicationHazard Communication

Hazard Communication Standard 29CFR 1910.1200

– OSHA published in 1988, requires, chemical manufacturers or importers to evaluate the hazards of the products they supply and summarize this information on Material Safety Data Sheets (MSDS), shipping labels, and product warnings

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Hazard CommunicationHazard Communication

Employers must supply this information to their employees and provide training on:– The chemical hazards found in their work place. This

includes training on reading hazard labels and MSDS, physical and health hazards of the chemicals, how to detect releases, the use of any required personal protective equipment (PPE), and the details of the hazard communication program.

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Hazard CommunicationHazard Communication

Specific laboratory requirements include:– Ensuring all incoming chemical containers are

labeled,

– MSDS are received with incoming chemicals and are readily accessible to laboratory employees at all times, while working in their labs,

– Ensure all laboratory, employees are trained on the physical and health hazards associated with the chemicals used including:

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Hazard CommunicationHazard Communication

Methods and observations that may be used to detect the presence or release hazardous chemicals in the work area,

The measures employees can take to protect themselves from chemical hazards, such as work practices, emergency procedures, and PPE.

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Hazard CommunicationHazard Communication

Laboratories that ship hazardous chemicals are considered either a chemical manufacturer or distributor under this standard and must also comply with the shipping requirements, including labeling containers, using proper shipping names and preparing an MSDS to be provided to the recipients

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Each MSDS must contain the Each MSDS must contain the following information:following information:

1. Suppliers name, address, ph #, date,

2. Chemical name, CAS # of all hazardous ingredients if it is > 1% of the product,

3. Physical and chemical characteristics, vp., fp.,

4. Physical hazards, including reactivity,

5. Health hazards, including signs and symptoms of exposure, medical conditions that might be aggravated by exposure,

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Each MSDS must contain the Each MSDS must contain the following information:following information:

6. Primary routes of entry,

7. PELs, RELs, TLVs 10. Toxicity data,11. Storage and

handling data,

12. Emergency and first aid procedures,

13. Disposal considerations

14. Transportation information

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Additional sources of hazard Additional sources of hazard informationinformation

National Fire Protection Association NFPA 704 National Institute of Occupational Safety and

Health (NIOSH) RELs. American Council of Governmental Hygienists

(ACGIH) TLVs International Agency for Cancer Research,

(IARC)

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Additional sources of Additional sources of hazard informationhazard informationNational library of Medicine (NLM)Toxline, MedlineHazardous substance Data Base (HSDB)Registry of Toxic Effects of Chemical

Substances (RTECS)MSDS database e.g. SIRI

http://www.SIRI.org

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Other hazard classification Other hazard classification systemssystems

The NFPA 704 System is a means of providing hazard information for a material. Each of the four sections is associated with a particular hazard and the higher the number the more hazardous the material is for that particular characteristic. The fourth section is to give information on special hazards. Next are the four sections and an explanation of each.

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Red=FlammabilityRed=Flammability •

4-Materials with a flashpoint below 73 F (22 C) and a boiling point below 100 F.

3-Materials with a flashpoint below 73 F and a boiling point greater than or equal to 100 F (38 C) or a flashpoint above 73 F and less than 100 F.

2-Materials with a flashpoint above 100 F, but not exceeding 200 F (93.3 C).

1-Materials with a flashpoint above 200 F.

0-Materials which normally won't burn.

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Blue-Health HazardBlue-Health Hazard4-Materials with an oral LD50 of less than or equal to 5 mg/kg.

3-Materials with an oral LD50 above 5, but less than 50 mg/kg.

2-Materials with an oral LD50 above 50, but less than 500 mg/kg.

1-Materials with an oral LD50 above 500, but less than 2000mg/kg.

0-Materials with an oral LD50 above 2000mg/kg.

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Yellow=Reactivity HazardYellow=Reactivity Hazard

4-Material is capable of explosion or detonation at normal temperature and pressure.

3-Material is capable of explosion, but requires a strong initiating source, or the material reacts with water.

2-Material undergoes violent chemical changes at elevated temperature and pressure.

1-Normally stable, but can become unstable at elevated temperatures.

0-Normally stable.

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White = Special HazardWhite = Special Hazard

W Water Reactive

Ox Oxidizer

COR Corrosive

Radiation

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Routes of ExposureRoutes of Exposure

Inhalation - Most common route of exposure, lungs are designed for maximum transport and adsorption of vapors, large surface area (1000 sf)

Dermal – Second most common route of exposure, lipid (pass with greater ease) and water soluble chemicals can pass through the skin. Has 20 sf surface area.

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Routes of ExposureRoutes of Exposure

Ingestion – can occur through food contamination, eating drinking in lab, poor hygiene, mucociliary transport of vapors trapped in upper air ways,

Injection – Can occur through injury and needle sticks

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Lethal ConcentrationLethal Concentration

Lethal Concentration- LC-50, pertains to inhalation hazards. It is the concentration of a material in air that will kill 50% of the test subjects when administered as a single exposure (typically 1 to 4 hours). This value gives you an idea of the relative toxicity of the material. This value applies to vapors, dusts, mists and gases.

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Lethal DoseLethal Dose

An LD50 value is the amount of a solid or liquid material that it takes to kill 50% of test animals in one dose. The dose may be administered orally (by mouth), or injection into various parts of the body. The value is usually reported along with the administration method.

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Acute Toxicity LevelsAcute Toxicity Levels

 

Toxicity LD-50 (rats)

LD-50(rabbits)

LC- 50 (rats)

Probable lethal human dose

Extremely Toxic

<1mg <10ppm <10ppm A taste, 1 grain

Highly Toxic 

1-50 mg 10-100 ppm

10-100 ppm

1 tea, 4 cc

Moderately Toxic

50-500 mg

100-1000 ppm

100-1000 ppm

1 oz, 30g.

Slightly Toxic

500-5000 mg

1000-10,000

1000-10,000

1 pint, 250g

Mg//kg body weight

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Acute ToxinsAcute Toxins

Acute toxicity is the ability of a chemical to cause harm after a single exposure. They can cause local, or systemic effects or both. Chemicals that have a high level of acute toxicity (very low LD, LC-50s) are defined as particularly hazardous substances by the Lab Standard and require special handling procedures to be added to the lab CHP.

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Acute ToxinsAcute Toxins

These include: acrolein, arsine, chlorine, diborane, diazomethane, hydrogen cyanide,hydrogen floride, sodium cyanide, dimethyl mercury, etc.

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Chronic ToxicityChronic Toxicity

Harm occurs through repeated usually lower levels of exposure. Includes most carcinogens, reproductive hazards, some heavy metals. Many have a long latency period. Generally the longer the exposure the greater the hazard.

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Factors affecting toxicityFactors affecting toxicity

The potential for toxic effects is determined by the dose, the duration, the frequency and the route of exposure.

Synergistic effects - the combination of the toxic effects of two substances may be significantly greater than the toxic effect of either substance alone.

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Reproductive toxinsReproductive toxins

Reproductive toxins are those that have an adverse effect on reproduction including: fertility, gestation, lactation and general reproduction performance. Mutagens affect the genetic material. Teratogens effect the development of the fetus. Ethylene dibromide and dibromochloropropane are well known male reproductive toxins. Others include:

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Reproductive toxins cont.Reproductive toxins cont.

vacetaldehyde, acrylicacid, aflatoxins, aniline arsenic, benzene, benzo(a)pyrene, cadmium, carbondisulfide, chromic acid, chloroform, chloroprene, N,N-dimethylacetamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dinitrooctylphenol ,di-sec-octyl-phthalate, diphenylamine, dithane, estradiol, 2-ethoxyl ethanol, 2-ethoxyetyl acetate, ethyl thiourea, 2-ethylhexanol, formaldehyde, formamide, glycol ethers, halothane, hexachlorobenzene, hexafluoroacetone, hydrazine(s),

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Reproductive toxins cont.Reproductive toxins cont.

iodoacetic acid, karathane, lead compounds, mercury compounds, 2-methoxy ethanol, 2-methoxy- ethylacetate, methylchloride, N-methyl-2-pyrolidone, nitrobenzene, nitrousoxide, phenol, polychlorinated and polybrominated biphenyls, propylene glycol, monomethyl ether, propylene glycol, monomethyl ether acetate, propylene oxide, systhane, TOK(herbicide),toluene, trichloroethylene, vinyl- chloride, xylene

Additional information @ Reproductive Hazards

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Medical Surveillance Medical Surveillance programsprogramsUse of certain chemicals at particular

exposure levels require the participation a medical surveillance programs.

Medical Screening/Surveillance

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CarcinogensCarcinogens

Chemical capable of causing changes in the DNA resulting in uncontrolled growth of cells or cancer. They are insidious because no immediate harmful effects are felt. Latency period can be from 20-30 years

Usually results from chronic exposures

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CarcinogensCarcinogens

Defined in the Lab Standard as a chemical that is:– Regulated by OSHA as a carcinogen,

– It is listed by the National Toxicology Program,

– It is listed as a group 1 under IARC (international agency on cancer research),

– It is listed as a group 2A, or 2B under IARC probable and possibly carcinogenic to humans.

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CarcinogensCarcinogens

Examples of "Select Carcinogens“

Examples of “Classes of Carcinogens”

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ConclusionConclusion

Risk assessment for use of hazardous chemicals includes:

1. Identify chemicals to be used and circumstances of use,

2. Consult sources of information,

3. Evaluate type of toxicity,

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ConclusionConclusion

4. Consider possible routes of exposure,5. Evaluate quantitative information on toxicity,6. Select appropriate procedures to minimize

exposure following hierarchy of protection,a. Eliminate the hazardb. Substitute or reduce the hazard

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ConclusionConclusion

c. Engineering Controls – Fume Hood, Glove boxes

d. Administrative Controls – CHP, SOPs

e. Personal Protective Equipment – gloves, goggles

7. Prepare for contingencies.