Glossary
PACM
Also: Presumed Asbestos-Containing Material
Material that, by virtue of its type and age, is presumed to contain asbestos unless tested and shown not to.
PACM stands for Presumed Asbestos-Containing Material. OSHA 29 CFR 1926.1101(b) defines PACM as thermal system insulation and surfacing material found in buildings constructed before 1981.
The PACM concept exists because surveying every square foot of an old building for asbestos is impractical. The rule presumes that pre-1981 TSI and surfacing material is asbestos-containing unless the building owner has rebutted the presumption through inspection by an accredited inspector and bulk-sample testing.
For abatement and demolition contractors, the practical consequence is that work on TSI or surfacing material in a pre-1981 building is performed under asbestos protocols by default. The owner can lift the presumption by providing inspection results showing the material is not asbestos-containing.
PACM and ACBM are not interchangeable: ACBM is material confirmed by testing to contain more than 1% asbestos. PACM is material presumed to be ACBM in the absence of testing.