A respirator cartridge or canister is a type of filter that removes gases, volatile organic compounds (VOCs), and other vapors from air through adsorption, absorption, or chemisorption. It is one of two basic types of filters used by air-purifying respirators. The other is a mechanical filter, which removes only particulates. Hybrid filters combine the two.
Workplace air that is polluted with fine particulate matter or noxious gases but that contains enough oxygen (in the US, this is ruled to be a concentration above 19.5%; in the Russian Federation, above 18%[citation needed]), can be rendered safe via air-purifying respirators. Cartridges are of different types, and must be chosen correctly and replaced on an appropriate schedule.[1][2]