Exposure Limits

An important aspect of the Lead Standard is the established maximum limits of exposure to lead for all workers, including a permissible exposure limit (PEL) and action level (AL). The PEL and AL will tell employers what levels of lead exposure are allowed in the workplace, and at what point to start taking actions to protect workers from lead overexposure.

PEL

The PEL is the maximum worker lead exposure allowed. The U.S. PEL is 50 micrograms of lead per cubic meter of air (50µg/m³). This exposure is for an average over an eight-hour period.

What happens if employees are exposed to lead for more than eight hours in a workday? In this case, their allowable exposure as a time-weighted average (TWA) for that day must be reduced according to this formula:

Employee exposure (in µg/m³) = 400 divided by the hours worked in the day

AL

The AL is the level at which an employer must begin specific compliance activities ("actions") outlined in the standard. The U.S. AL is an airborne concentration of 30µg/m³. The AL is averaged over an eight-hour period.

To learn more about Construction Lead Safety visit our Construction Lead Safety Online Training Certification web page.