What term is used for the maximum airborne concentration of a substance that should not be exceeded?

• A. TLV
• B. STEL
• C. PEL
• D. LD-50

Answer: (C)

The term used for the maximum airborne concentration of a substance that should not be exceeded is known as a Permissible Exposure Limit (PEL). PELs are established by regulatory agencies such as the Occupational Safety and Health Administration (OSHA) for various hazardous materials to protect workers from potential health risks associated with inhaling harmful substances over an 8-hour work shift.

These limits are concerned with occupational safety and are based on scientific research and exposure data, helping to ensure that employees are not exposed to harmful levels of chemicals that can affect their health. The importance of PELs lies in their role in maintaining a safe working environment, ensuring that concentrations are below levels known to cause adverse health effects.

In contrast, other terms such as Threshold Limit Values (TLVs) and Short-Term Exposure Limits (STELs) relate to exposure guidelines and recommendations, while LD-50 refers to a measurement used to indicate the median lethal dose of a substance, which is unrelated to airborne concentration limits.