Personal Protective Equipment and Respiratory Protection
Respiratory Protection
Respirators are the last line of defense. Candidates must know the difference between negative-pressure (half-face and full-face air-purifying) and positive-pressure (PAPR and supplied-air) respirators. OSHA requires a written respiratory protection program, medical evaluation, fit testing, and training. Fit testing must be done before use and annually, and users must be clean-shaven where the seal contacts the face.
Selection and Assigned Protection Factors
Know that higher-exposure tasks require higher protection. Assigned protection factors (APFs) matter: a half-face APF is 10, a full-face is 50, a PAPR is higher, and supplied-air with a full facepiece is higher still. Filter selection matters: HEPA filters for particulates; organic vapor/acid gas cartridges where other hazards exist.
Traps to Watch
Common traps: (1) assuming a dust mask is acceptable (it is not); (2) forgetting that a PAPR still requires a fit test; (3) confusing filter type with cartridge type; (4) assuming a beard is acceptable; (5) assuming respirators eliminate the need for engineering controls. Also remember that disposable coveralls and other PPE are used with, not instead of, respirators.
Rule of Thumb
Match protection to exposure: if in doubt, move up the protection ladder - half-face to full-face to PAPR to supplied-air.
Worked Example
A worker in a containment with visible dust asks whether a half-face respirator is enough. If monitoring shows exposure above the half-face APF, the correct answer is to upgrade to a higher-protection respirator and improve controls - not to add a second cartridge.