Respiratory protection products are one of the largest categories of PPE, with three primary groups: Air purifying respirators (Gas masks, PAPR), Supplied air respirators (SCBA), and Escape hoods.
Gas masks are also known as “air-purifying respirators” because they filter or clean chemical vapors and aerosols out of the air as you breathe. The respirator includes a face piece or mask, and a filter/cartridge. Straps secure the face piece to the head and when the user inhales, air is pulled through the filter. Air purifying cartridges/canisters protect from broad-scope CBRN threats and applicable in unknown threat scenarios; these are included as accessories.
Powered Air Purifying Respirators (PAPR) use a fan to blow air through the filter to the user. They are easier to breathe through and need a fully charged battery to work properly. PAPR are used when the threat material identity AND concentration are known. They are used in tandem with purifying cartridges/canisters and should only be used if the oxygen levels are at or above 19%. PAPRs are most commonly associated with biological use.
Supplied air respirators include Self-Contained Breathing Apparatus (SCBA) and are used if the situation demands long-term (> 1 hour) exposure to an unknown threat at unknown concentrations or in oxygen deficient environments. They contain an air tank, are heavy (typically > 30 pounds), and require special training to use and to maintain. The air tanks typically last an hour or less depending upon rating and how fast the user is breathing.
Escape hoods are intended for temporary (< 30 minutes) single use to move to a safe area. Table 4 shows data fields specific to respiratory protection performance.