What type of materials require a physical assessment under AHERA?

The rationale behind the requirement for a physical assessment under the Asbestos Hazard Emergency Response Act (AHERA) is centered on the management and identification of materials that may pose a risk due to asbestos content. The correct option emphasizes the need to assess all known friable materials and any assumed Asbestos-Containing Materials (ACM).

Friable materials are those that can be easily crumbled or reduced to powder when dry, which makes them more likely to release asbestos fibers into the air when disturbed. This presents a significant health risk to occupants and workers, necessitating thorough assessment and management strategies.

Additionally, assuming that certain materials contain asbestos, based on the context of their use or location, is a standard practice in hazardous materials management. This means that even if asbestos is not visibly identified, any material that is assumed to be ACM still needs to be physically evaluated to determine its condition and potential risk.

This systematic approach ensures that both existing risks (documented friable materials) and potential risks (assumed ACMs) are adequately evaluated, enabling appropriate actions to be taken to protect health and safety.