Final answer:
Permissible exposure limits in the workplace are mandated by the Occupational Safety and Health Administration (OSHA), a United States Department of Labor agency tasked with ensuring worker safety and health.
Step-by-step explanation:
Permissible exposure limits are mandated by the Occupational Safety and Health Administration (OSHA), which is an agency of the United States Department of Labor. OSHA's role is to preserve the safety and health of workers by implementing health and safety regulations. This includes setting limits on hazardous chemical exposure and issuing standards for a variety of workplace hazards.
The Environmental Protection Agency (EPA) also plays a significant role in environmental protection and public health by ensuring safe drinking water and setting standards for environmental contaminants, but the primary agency responsible for regulating workplace exposure limits is OSHA.