American Chemical Society (ACS) Laboratory Safety Practice Test

The term "Permissible Exposure Limit" (PEL) refers to a legal limit on the concentration of a substance in the workplace air, which is established by regulatory agencies such as the Occupational Safety and Health Administration (OSHA). PELs are important because they define the maximum allowable level of exposure to hazardous chemicals over a specified time, typically an 8-hour workday or a 40-hour workweek. These limits are designed to protect workers from harmful effects caused by inhalation and ensure safe working conditions.

Setting a PEL involves scientific research and risk assessment to determine the concentration at which exposure is unlikely to cause health issues for most adults. Compliance with PELs is mandatory for employers, making them a crucial component of workplace safety regulations. Understanding PELs is essential for laboratory personnel to ensure that they operate within safe exposure limits when handling potentially hazardous substances, thus mitigating the risk of adverse health effects.

The other options, while relevant to safety and laboratory practices, do not correspond to the definition of PEL. Recommendations for lab setup, exposure duration, and guidelines for personal protective equipment (PPE) each serve different roles in laboratory safety protocols but do not encapsulate the legal and health implications that PEL addresses.