Respirators | NIOSH | CDC
A Guide to Air-Purifying Respirators. DHHS (NIOSH) Publication Number 2018-176 (August 2018) Air-purifying respirators (APRs) work by removing gases, vapors, aerosols (airborne droplets and solid particles), or a combination of contaminants from the air through the use of filters, cartridges, or canisters. These respirators do not supply oxygen ...