Glossary
Decontamination Unit
Also: Decon unit, Decon
A staged enclosure attached to an asbestos work area where workers shower and change clothes when leaving the work area to prevent fiber transport.
A decontamination unit (commonly “decon”) is a multi-stage enclosure attached to an asbestos work area where workers progressively remove contaminated clothing and shower before leaving to clean areas.
For Class I asbestos work under OSHA 1926.1101, the decon unit must have three connected rooms: an equipment room (where workers remove their work clothes and protective equipment), a shower room (where workers shower before changing back to street clothes), and a clean change room (where street clothes are kept).
The unit is connected to the negative-pressure work area such that workers always pass through the shower when moving between contaminated and clean spaces. Air flows from clean to dirty.
Mini-decon units may be used for smaller Class I jobs and for Class II and III work, with reduced staging based on the work scope.