Respiratory equipment protects users against insufficient oxygen environments, harmful dusts, fogs, smokes, mists, gases, vapors, and sprays. These wearable devices are used to filter airborne contaminants or to provide clean, breathable air to the user.

NIOSH-approved respiratory protection consists of two main types: air-purifying respirators (APRs) and atmosphere-supplied respirators (ASRs). It is crucial to identify all respiratory hazards within an environment before choosing a type of respirator.

APRs remove particles, gases, vapors, aerosols, or a combination of contaminants from the air using filters, cartridges, or canisters. APR types include:

• Particulate filtering facepiece respirators (FFRs) – Limited-use, multi-layer masks that filter out airborne particles. Available with or without an exhalation valve. 
• Half-mask and full-face respirators – Reusable masks that use filters, cartridges, or canisters to remove contaminants. See for product selection.
• Powered air purifying respirators (PAPRs) – Reusable systems that utilize a blower to force ambient air through a purifying element before it reaches the user. Used in conjunction with a tight-fitting facepiece or respiratory system hood or helmet, depending on application.

ASRs provide clean breathing air from a non-ambient source. These respirators protect workers from many types of airborne contaminants (particles, gases, and vapors) and, in certain cases, oxygen-deficient atmospheres. ASR types include:

• Supplied air respirators (SARs) – Use a remote air source such as a compressor or breathing cart to provide Grade D breathable air. Complete systems include a supplied airline hose, air regulating valve, breathing tube, and respiratory system hood or helmet.
• Emergency escape breathing apparatus (EEBA) – Typically consists of a small portable air cylinder to provide short-term protection from contaminated air so users can evacuate quickly from an unsafe area.
• Self-contained breathing apparatus (SCBA) – Feature back-mounted cylinders filled with breathable compressed air and are commonly used by firefighters or others who may be exposed to immediately dangerous to life or health (IDLH) atmospheres.

Face masks are single-use barriers that cover a user’s nose and mouth and should not be used in lieu of OSHA-standard respiratory protection.

Fit testing kits are designed to evaluate respirator fit, determine device suitability, and adhere to compliance requirements. Tight-fitting APRs and ASRs and particulate FFRs require initial and annual fit testing. EEBA, loose-fitting hoods, and face masks do not require fit testing.

Regulatory compliance details can be obtained at the individual product level.