Under AHERA, when is a homogeneous area considered to not contain ACM?

Under the Asbestos Hazard Emergency Response Act (AHERA), a homogeneous area is considered not to contain asbestos-containing material (ACM) when all bulk samples taken from that area show asbestos present in concentrations of less than 1%. This is significant because the federal regulations define ACM as any material containing 1% or more asbestos by volume. Therefore, if all samples demonstrate that the asbestos concentration is below this threshold, it can be concluded that the area does not meet the criteria for ACM.

This understanding is crucial for compliance with AHERA regulations, as it guides decisions about how to handle materials in schools and other facilities. When sampling reveals asbestos levels below 1%, it also allows property owners to make informed decisions for management and potential remediation of materials, leading to more effective safety measures.

In contrast, if any sample shows asbestos in excess of 1%, this would classify the material as ACM, necessitating more stringent management or abatement actions. Meanwhile, the condition of the material and the nature of the materials tested would not solely determine the presence of ACM. Therefore, visible damage or deterioration and testing only for thermal system insulation (TSI) without broader sampling do not provide conclusive decisions regarding the presence or absence of ACM in homogeneous areas.