Reusable respirator cartridges and filters purify the air in workplace environments that contain heavy dust, fumes, gases and vapors. Cartridges and filters are available in different types. Some cartridges filter out gas and vapors, while others filter out only organic vapors. Filters typically protect against dust particulates and non-oily mists. However, some protect against both oily and non-oily mists. Cartridges and filters must be replaced on a regular schedule because they become clogged and less effective over time.