Glossary
Class I Work
The most stringent category of asbestos work under OSHA 1926.1101: removal of thermal system insulation or surfacing material that contains asbestos.
Class I asbestos work is OSHA’s most stringent category, defined in 29 CFR 1926.1101(b). It covers the removal of thermal system insulation (TSI, the insulation on pipes, boilers, tanks, ducts, and equipment) and surfacing material (sprayed-on or troweled-on material applied to ceilings, walls, or structural elements) that is ACM (asbestos-containing material) or PACM (presumed asbestos-containing material).
Class I work requires the highest level of controls: a competent person on site at all times during the work, a Negative Pressure Enclosure for large projects, Decontamination Unit (three-stage), specific work practices (wet methods, glove bags, mini-enclosures depending on scope), and personal air monitoring of each worker.
The work also requires use of accredited workers and supervisors per OSHA, with state-issued licenses on top in jurisdictions that have asbestos licensing programs.