Chemical Exposure Limits & Monitoring
Chemical Exposure Limits
The OSHA Laboratory Standard requires that laboratory employee exposures of OSHA Regulated Substances do not exceed the Permissible Exposure Limits as specified in 29 CFR Part 1010, subpart Z. The Permissible Exposure Limits (PEL) are based on the average concentration of a chemical to which workers can be exposed to over an 8-hour workday, 5 days per week, for a lifetime without receiving damaging effects. In some cases, chemicals also have a Ceiling © limit, which is the maximum concentration that cannot be exceeded. OSHA has established PELs for over 500 chemicals.
Another measure of exposure limits are Threshold Limit Values (TLV) which are recommended occupational exposure limits published by the American Conference of Governmental Industrial Hygienist (ACGIH). Similar to PELs, TLVs are the average concentration of a chemical that a worker can be exposed to over an 8-hour workday, 5 days per week, for a lifetime without observing ill effects. TLVs also have Ceiling (C) limit, which are the maximum concentration a worker can be exposed to at any given time. The ACGIH has established TLVs for over 800 chemicals. Both PELs and TLVs can be found on SDS. Another good resource for information is the National Institute for Occupational Health and Safety (NIOSH).
Chemical Exposure Monitoring
EHRS is available to monitor and evaluate exposures to chemicals in the workplace to measure the success of a hazard control programs or to assess level of exposure prior to design a program. Contact EHRS for additional information.
Exposure Monitoring Methods
Monitoring can be accomplished through the use of direct reading instruments such as portable photoionization detector which gives an instantaneous but sometimes nonspecific reading.
The OSHA-approved method for monitoring involves placing a sampling badge on an individual or by drawing air through tubes or filters over the course of a specified time lapse by using personal sampling pump, then having the samples analyzed by an independent environmental laboratory.
Exposure Evaluation
The results will be interpreted according to accepted industrial hygiene practices and compared to the OSHA Permissible Exposure Limits (PEL) and Action Level (AL).
If exposure levels require additional exposure prevention and control, EHRS will determine the appropriate modification to the work activity as described by section IV. Controlling Risk of Chemical Hazards.