Which statement about BEI is correct?

• A. BEI measures ambient air concentrations.
• B. BEI is a legally enforceable limit for airborne concentrations.
• C. BEI is a recommended protective guideline for radiation exposure.
• D. BEI indicates biological monitoring limits to assess body burden.

Answer: (D)

Biological Exposure Indices are values used in biological monitoring to interpret how much of a chemical or its metabolite is present in a worker’s body. They serve as indicators of body burden and help decide when medical surveillance or exposure controls are needed, rather than measuring the air in the workplace. They’re recommended guidelines, not legally enforceable limits, and they apply to chemical exposures, not radiation dose.

The statement that BEI indicates biological monitoring limits to assess body burden is the best fit because it directly describes how BEIs are used: they reflect internal dose from exposure and guide actions based on that internal burden. For example, if a biological sample like blood or urine exceeds a BEI for a substance, it signals higher body burden and the need for further evaluation or intervention.