Are worker exposure limits met?
Your facility must ensure that workers are not exposed to airborne asbestos concentrations in excess of either of the following limits, collectively referred to as permissible exposure limits (PELs):
• 0.1 fiber per cubic centimeter (f/cc) of air averaged over an eight-hour work shift. This PEL is called the time-weighted average (TWA) limit.
• 1.0 f/cc of air averaged over a sampling period of 30 minutes. This PEL is called the excursion limit.Courtesy of The EPA