Glossary
Enclosure
Constructing an airtight, impermeable, permanent barrier around ACM to prevent fiber release into the occupied space.
Enclosure as a response action means constructing an airtight, impermeable, permanent barrier around asbestos-containing material so that fibers cannot reach the occupied space.
This is different from the temporary Negative Pressure Enclosure used during abatement work. An enclosure as a response action is a permanent solution: a sealed soffit around an asbestos-wrapped pipe, a sheetrock wall built in front of an asbestos-containing surface, with all penetrations sealed.
Like Encapsulation, enclosure leaves the ACM in place. It must continue to be managed through the building’s O&M program, with periodic inspection to verify the enclosure remains intact. Any future work that breaches the enclosure brings the asbestos work practices back into play.