Presumed Asbestos-Containing Material (PACM)

Presumed asbestos-containing material, or PACM, is OSHA's term for thermal system insulation and surfacing material in buildings built in 1980 or earlier. Building owners and employers must treat it as asbestos unless testing or other proof shows it is not.

Origin

OSHA introduced the PACM presumption in its 1994 revisions to the asbestos standards for construction and general industry. The same rules require resilient flooring and its mastic installed in 1980 or earlier to be treated as asbestos-containing unless shown otherwise.

Significance in Asbestos Context

The presumption puts the burden on building owners and employers to find out, rather than assume materials are safe. Owners must determine the presence, location and quantity of asbestos and PACM, tell workers and contractors who may disturb it, and post or label certain areas. A presumption can be rebutted by an inspection and testing by a qualified person. For someone exposed during later renovation or maintenance of an older building, the rule can help show that the owner or employer should have known asbestos was likely present and should have warned. Many products used before 1981 did contain asbestos, which is why the cutoff was drawn there.

Example Sentence

The school district had treated the pipe insulation as PACM for years, but when contractors removed it without warning, custodial staff were exposed.

Related Terms

Asbestos-Containing Material (ACM), OSHA Asbestos Standard, Thermal System Insulation (TSI), Surfacing Material, Vinyl-Asbestos Tile, OSHA Class I–IV Asbestos Work

Notes

• If you work in a building built before 1981, ask your employer whether an asbestos survey exists.
• Notices or labels about asbestos at your workplace are worth photographing and keeping.