3M Center for Respiratory Protection
Choosing the right respirator is key. No matter how well made your respirator is, it can’t filter out hazards that it’s not designed for. Once you have the results of your exposure assessment, you’re ready to select appropriate protection for your employees.
The only respirators OSHA allows for use in the workplace are those approved by the National Institute for Occupational Safety and Health (NIOSH). All NIOSH-approved respirators have an assigned protection factor (APF), which can range from 10 to 10,000.
The APF is the workplace level of respiratory protection that a respirator or class of respirators is expected to provide to employees when the employer implements a continuing, effective respiratory protection program as specified by 29 CFR 1910.134. For instance, an APF of 10 means the respirator can protect against exposure levels that are up to 10 times the PEL for that hazard.
To see what level of APF your workplace needs, divide your exposure levels by the exposure limit. (This is called the “hazard ratio.”) For instance:
Exposure level: 500 ppm
OEL or PEL: 50 ppm
Respirators are classified by the type of hazard they protect against, their APF and the specific substance(s) they’re approved for. There are other ways that you may also commonly see respirators classified as well, such as:
Negative-pressure respirators rely on the wearer to pull air in through cartridges or filter. This has the potential to put a strain on the wearer, which is why medical evaluations are important (and required).
Disposable respirators, also known as filtering facepieces, are used to help protect against some particulate hazards. They’re lightweight and require no maintenance since they’re discarded after use.
Reusable respirators can be used with particulate filters, gas and vapor cartridges or combination cartridges, which may need to be replaced on a schedule or as needed.
Half-face respirators cover the lower half of the face, including the nose and mouth.
Full-face respirators cover the eyes and much of the face, and can sometimes replace the need for safety glasses.
Positive-pressure respirators do the work of pushing air to the respirator headtop or facepiece; they can either be powered-air, using a battery-powered blower to pull air through a filter, or supplied-air, bringing clean air through a hose from a source outside of the contaminated work area.
Tight-fitting respirators must be fit-tested when use is required, and users must perform seal checks every time a tight fitting negative pressure respirator – a filtering facepiece or half facepiece respirator - is worn.
Loose-fitting respirators typically have a hood or helmet.
Self-contained breathing apparatus (SCBA) is classified as a positive pressure supplied air respirator, but is different from all other respiratory equipment in that the user carries the source of the clean air with them in a tank. This type is mainly used for conditions that are unknown or “immediately dangerous to life or health” (IDLH), such as oxygen-deficient atmospheres, when hazards are so concentrated or so toxic they can’t be brought to acceptable levels with other types of respiratory protection, or when you’ve been unable to definitively record the level of hazard in the workplace.
Understanding the different types of particulate filters and gas and vapor cartridges can help you select the right one. NIOSH categories and labels are useful systems to learn about.
For particulate filters, NIOSH has 10 different categories, nine for negative-pressure filters and one for for powered air-purifying filters [PAPRs]).
The negative-pressure categories are based on a combination of two factors:
Learn more about respirators that meet the needs of any work environment. Half or full facepiece reusable respirators help protect against both particles and/or gases and vapors.
Learn more about the extensive family of 3M disposable respirators (N95 – P100) that offer a full range of comfort, convenience and features that help you meet your needs.
Learn more about respirators that deliver a comfortable stream of clean air to the wearer either using a battery-powered motor blower (Powered Air Purifying Respirators – PAPR) or from a pressure pump (Supplied Air Respirators – SAR).
We have respirators that can help protect against chemicals as well as particulate hazards, including oily mists. We can also help you with your selection process:
The 3M Respirator Selection Guide provides respirator selection criteria for particulate hazards and a wide range of chemical compounds.
Our free 3M™ Select and Service Life Software can help make selecting the appropriate respirators faster and easier. Just enter contaminants and their concentrations and the software analyzes the data and profiles a record of your choices. The software can also help you estimate the service life of 3M™ Respirator Cartridges, which aid in maintaining you OSHA-required cartridge change schedule for gas and vapor cartridges.
For more information about respirator selection, go to our website or call 3M Technical Service at 1-800-243-4630.