5. How long can a particulate respirator be used before it must be discarded ?

Respirators with replaceable filters are reusable, and a respirator classified as disposable may be reused depending upon the intensity of particulate matter in the atmosphere. All filters must be replaced whenever they are damaged, soiled, or causing discomfort to the wearer (e.g. increased breathing resistance). Before each use, the exterior of the filter material should be inspected. If the filter material is physically damaged or soiled, the filter should be changed (in the case of respirators with replaceable filters) or the respirator discarded (in the case of disposable respirators). Always follow the user instructions provided by the manufacturer. Employers must develop standard operating procedures for storing, reusing, and disposing of respirators that have been designated as disposable and for disposing of replaceable filter elements.