Permissible Exposure Limit (PEL)
The Occupational Safety & Health Administration (OSHA) issues Permissible Exposure Limits (PELs), which are regulations applied to workplace environments intended to protect workers against the negative health consequences of hazardous substances. PELs limit the amount or concentration of a substance in the air (1).
For example, OSHA dictates that asbestos
particles cannot permeate the workplace atmosphere beyond a certain extent, measured in fibers per cubic centimeter of air. Specifically, environments containing asbestos must have no more than 0.2 fibers per cubic centimeter of air averaged over an eight-hour work shift, or one fiber per cubic centimeter of air if the employees' time at the environment is of a short duration (2). Employers who fail to comply with PELs are subject to fines and other penalties.