What is the permissible exposure limit (PEL) for asbestos over an 8-hour time-weighted average (TWA)?

The permissible exposure limit (PEL) for asbestos is established to protect workers from the health risks associated with inhaling asbestos fibers. The correct limit is 0.1 fibers per cubic centimeter (f/cc) over an 8-hour time-weighted average (TWA). This value is determined based on research demonstrating that exposure to this level minimizes the risk of developing serious health issues, such as asbestos-related lung diseases and cancers.

Setting the PEL at 0.1 f/cc reflects a cautious approach to occupational safety, as even low levels of asbestos can pose significant health risks over time. Regulations are designed to ensure that workers are not exposed to harmful concentrations that could lead to adverse long-term health effects.

The other options represent levels that exceed the maximum acceptable limit, which does not align with current health standards and guidelines aimed at minimizing exposure risks. The designation of 0.1 f/cc as the PEL underscores the importance of maintaining stringent exposure limits in environments where asbestos is present.