A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres including fumes, vapors, gases, and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories of respirators: air-purifying respirators and air-supplied respirators.

• Air-purifying respirators draw in the surrounding air and purify it before it is breathed. They range from relatively inexpensive, single-use, disposable face masks sometimes referred to as a filtering facepiece respirator to a more robust reusable model with replaceable cartridges called an elastomeric respirator. Powered air-purifying respirators (PAPR) use a pump or fan to constantly move air through a filter and supply purified air into a mask, helmet, or hood.

• Air-supplied respirators provide clean breathing air from a source independent of the work area. These respirators will protect wearers from many types of airborne contaminants (particles, gases, and vapors) and, in certain cases, oxygen-deficient atmospheres. There are three types of air-supplied respirators: supplied-air respirators (SARs), self-contained breathing apparatus (SCBAs), and combination SARs/SCBAs.

Respirators should only be used when engineering control systems are not feasible or insufficient. Engineering control systems, such as adequate ventilation or scrubbing of contaminants, are the preferred control methods for reducing worker exposures.

Respirators can also contain droplets and particles you breathe, cough, or sneeze out so you do not spread them to others. They are made to protect you by filtering the air and fitting closely on the face to filter out particles, including the virus that causes COVID-19.