What percentage of asbestos by weight defines asbestos containing building material (ACBM)?

Asbestos containing building material (ACBM) is defined by the U.S. Environmental Protection Agency (EPA) as any material that contains more than 1% asbestos by weight. This standard is widely recognized and used in regulations concerning the management and abatement of asbestos in buildings.

The rationale behind this definition lies in the health risks associated with asbestos exposure. Materials containing more than 1% asbestos are considered significant enough to pose potential risks to human health and the environment, warranting careful handling and regulation. Thus, anything exceeding this threshold falls into the category of ACBM, necessitating strict compliance with safety guidelines and procedures during renovations, demolitions, or any activities that may disturb asbestos-containing materials.

In contrast, materials that contain 1% or less asbestos are typically not classified as ACBM, and while they may still contain asbestos fibers, they are generally viewed as posing a lesser risk unless damaged or disturbed in a way that releases fibers into the air. Therefore, choosing the definition that highlights "more than 1%" accurately reflects the established regulatory criteria for identifying asbestos containing building materials.