What are the OSHA requirements for Air Changes per Hour (ACH) in asbestos work areas?

The correct answer reflects the Occupational Safety and Health Administration (OSHA) standards, which state that for regulated asbestos work areas where the potential for airborne asbestos fibers is present, a minimum of four air changes per hour (ACH) is required to help ensure proper ventilation and reduce the concentration of airborne contaminants.

In practical terms, adequate air changes per hour help dilute and remove airborne asbestos fibers, thereby lowering the risk of inhalation exposure for workers. The requirement for four ACH is generally considered a baseline to maintain a safe environment in both active abatement sites and during the cleanup phase.

Other values such as 2, 6, or 8 ACH might not be aligned with OSHA regulations for asbestos control. Two ACH may not provide sufficient ventilation to significantly lower airborne concentrations of toxic fibers. Conversely, while six or eight ACH could be beneficial, they do not represent the minimum standard required according to OSHA guidelines.