Office of Security, Safety and Risk Management
Chemical Hygiene Plan
| B. | PROCEDURE-SPECIFIC SAFETY PROCEDURES All laboratory procedures must contain a written description of specific safety practices incorporating the applicable precautions described in this section. Employees should read and understand these practices before commencing a procedure. |
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B1. | Toxic Chemicals The Material Safety Data Sheets (MSDS)for many of the chemicals used in the laboratory will state recommended limits or OSHA-mandated limits, or both, as guidelines for exposure. Typical limits are threshold limit values (TLV), permissible exposure limits (PEL), and action levels. When such limits are stated, they will be used to assist the chemical hygiene officer in determining the safety precautions, control measures, and safety apparel that apply when working with toxic chemicals. | |
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1. | When a TLV or PEL value is less than 50 ppm or 100 mg/m3 the user of the chemical must use it in an operating fume hood or else in a glove box, vacuum line or similar device which is equipped with appropriate traps and/or scrubbers. If none are available, no work should be performed using that chemical. |
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2. | If a TLV, PEL or comparable value is not available for that substance, the animal or human median inhalation lethal concentration information, LC50, will be assessed. If that value is less than 200 ppm or 2000 mg/m3, (when administered continuously for one hour or less), then the chemical must be used in an operating fume hood or else in a glove box, vacuum line, or similar device which is equipped with appropriate traps and/or scrubbers. If none are available, no work should be performed using that chemical. |
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3. | Whenever laboratory handling of toxic substances with moderate or greater vapor pressures will be likely to exceed air concentration limits, laboratory work with such liquids and solids will be conducted in a working fume hood or in a glove box, vacuum line or similar device which is equipped with appropriate traps and/or scrubbers. If none are available, no work should be performed using that chemical. |