Which OSHA regulatory exposure limit indicates the maximum allowable concentration over a 40-hour workweek?

The Permissible Exposure Limit (PEL) is the correct answer because it defines the maximum allowable concentration of a hazardous substance that workers can be exposed to in a workplace over a standard 40-hour workweek. PELs are established by OSHA to protect workers from health hazards due to chemicals or other dangerous substances.

Understanding PELs is crucial for workplace safety, as they help ensure that exposure levels remain within a range that is considered safe based on current health standards and research. These limits take into account various factors, including exposure duration and frequency, which is why the 40-hour workweek is a significant measure for establishing these limits.

Other options represent different concepts related to exposure and safety practices. Threshold Limit Values (TLVs) are guidelines developed by the American Conference of Governmental and Industrial Hygienists (ACGIH) and are not legally enforceable like PELs. A Short-term Exposure Limit (STEL) refers to the maximum allowable concentration for a short duration—typically 15 minutes—while Action Levels (ALs) are set below the PEL and are used as triggers for additional investigation and protective measures. Understanding these distinctions emphasizes the importance of PELs as specific regulatory standards set by OSHA for safe workplace exposure.