Which term defines the maximum concentration of a substance to which workers may be exposed without adverse effects?

The term that defines the maximum concentration of a substance to which workers may be exposed without experiencing adverse health effects is referred to as the Permissible Exposure Limit (PEL). PELs are regulatory limits set by the Occupational Safety and Health Administration (OSHA) that specify the maximum allowable concentration of hazardous substances in the workplace air over an eight-hour workday and 40-hour work week. These limits are established to protect workers' health and are based on research into the toxic effects of various substances and their safe exposure levels.

While Threshold Limit Values (TLVs) are similar, they are guidelines recommended by the American Conference of Governmental and Industrial Hygienists (ACGIH) and do not have the same regulatory weight as PELs enforced by OSHA. Short Term Exposure Limits (STELs) apply to exposures that should not be exceeded during a short interval, typically a 15-minute period, and are used to manage acute exposure risks but are not the overall maximum limit like PEL. Immediate Danger to Life and Health (IDLH) refers to conditions that pose an immediate threat to life or health, indicating concentrations that are far above safe exposure limits, rather than a maximum allowable level.