The Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) is 0.02 ppm (0.05 mg/m3) as a time-weighted average (TWA) over an 8-hour work shift. This PEL also carries a "skin" designation, meaning that skin contact can contribute to overall exposure.
In simpler terms, employees should not be exposed to concentrations of the substance exceeding 0.02 parts per million in the air, averaged over an 8-hour workday. Exposure through skin contact must also be controlled to prevent exceeding this limit.
It's important to note that the National Institute for Occupational Safety and Health (NIOSH) has established an Immediately Dangerous to Life or Health (IDLH) value of 3 ppm for the substance. While the question specifically asks for the PEL, the IDLH is a related safety benchmark indicating a level of exposure that poses an immediate threat to life or health.
