NASCLA Accredited Commercial General ContractorGeneral RequirementsHard

A general contractor is managing a commercial renovation project where asbestos-containing materials (ACMs) have been identified. According to OSHA regulations, what is the MAXIMUM permissible exposure limit (PEL) for airborne asbestos fibers averaged over an 8-hour workday?

  1. A0.2 fibers per cubic centimeter (f/cc)
  2. B0.1 fibers per cubic centimeter (f/cc)
  3. C0.01 fibers per cubic centimeter (f/cc)
  4. D0.05 fibers per cubic centimeter (f/cc)
Show answer & explanation

Correct answer: B. 0.1 fibers per cubic centimeter (f/cc)

OSHA's PEL for asbestos is 0.1 f/cc averaged over an 8-hour workday. Contractors must ensure worker exposure does not exceed this limit through engineering controls, work practices, and personal protective equipment.

Why the other options are wrong

  • A. This is above the current OSHA PEL for asbestos exposure.
  • C. This is below the current OSHA PEL and might be a short-term excursion limit or an older/different standard.
  • D. This is not the current OSHA 8-hour PEL for asbestos.

OSHA Asbestos PEL

The maximum concentration of airborne asbestos fibers that workers can be exposed to over an 8-hour workday, as established by the Occupational Safety and Health Administration (OSHA).

  • Current 8-hour Time-Weighted Average (TWA) PEL is 0.1 f/cc.
  • Also has an Excursion Limit (EL) of 1.0 f/cc over a 30-minute period.
  • Requires employers to implement protective measures to stay below these limits.

Memory trick: One tiny fiber per ten cubic centimeters is the limit for eight hours.

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