Which statement correctly distinguishes permissible exposure limit (PEL) and biological exposure index (BEI)?

• A. PEL measures body burden.
• B. PEL sets workplace airborne concentration limits; BEI indicates biological monitoring limits to assess actual body burden.
• C. PEL is a legally enforceable limit for biological exposure.
• D. BEI is a publicly posted exposure level.

Answer: (B)

The main idea is distinguishing what each measure controls: air in the workplace versus what’s inside the worker’s body. A permissible exposure limit sets a maximum concentration of a chemical in the workplace air that workers can be exposed to. It’s a legally enforceable limit aimed at protecting workers from inhaling too much of the chemical. A biological exposure index provides guidance for interpreting biological monitoring results, such as urine or blood tests, to assess the actual internal dose or body burden. BEIs help determine whether exposure has led to higher internal levels and whether actions to reduce exposure are needed. They are not air limits and are not typically legal limits themselves.

That’s why the statement that PEL sets workplace airborne concentration limits and BEI indicates biological monitoring limits to assess actual body burden is the best fit. The other ideas mix up what PEL measures (air concentration, not body burden), misstate the enforceability regarding biological exposure, or imply BEIs are publicly posted exposure levels rather than interpretation guides for biological monitoring.