1.2.2 Powered Air-Purifying Respirators (PAPR)
PAPRs have a battery powered motor that draw air through a filter (for
particles), catridges or canisters (for gases or vapours), then deliver
filtered air under positive pressure to a hood or face piece. This
positive pressure inside the facepiece reduces inward leakage of
potentially contaminated air.(67) They may have a tight fitting half or
full facepiece or a loose fitting facepiece, hood or helmet.