The Basic Types of Respirators - And How to Select the Right One for Your Workplace
Respirators are a last resort and should only be used if other control methods do not adequately mitigate respiratory hazards.
Airborne contaminants in the workplace can pose serious health hazards for workers. Contaminants can vary from the fine dusts produced during construction or mining to the toxic fumes found in chemical plants. Viruses and bacteria also pose significant airborne hazards, especially in the medical industry.
Respirators are a critical piece of personal protection equipment (PPE) for any worker facing these types of hazards. However, using the wrong type can leave the user underprotected. It is important, then, for both employers and front-line workers to be familiar with the various types of respirators available and understand which ones are suitable for which hazard.
The Employer’s Obligation
OSHA 1910.134 (a) (2) requires employers to protect the health of their employees by providing each of them with necessary respirators suitable for their tasks and work environments.
Employers are also required, according to OSHA 1910.134 (c) to "develop and implement a written respiratory protection program with required worksite-specific procedures and elements for required respirator use.”
The Two Basic Types of Respirators
The first step to selecting the right type of respirator for a particular job is to understand the types of respirators and their intended purposes. There are two basic types of respirators: supplied-air respirators (SARs) and air-purifying respirators (APRs).
Which type of respirator will be required depends on the level of respiratory protection needed, as well as ensuring the proper size and shape to fit a worker’s facial contours.
Supplied-Air Respirators (SARs)
Supplied-air respirators include airline respirators, self-contained breathing apparatus (SCBA), and combination respirators.
SAR systems must meet standards for purity and moisture content, and pressure must be regulated. SAR systems are available as tight-fitting full-face or half-face respirators. They provide air either through an airline that is fed from an uncontaminated air source located away from the hazards or through a compressed air tank.
- Airline respirators: These are used for extended periods in non-IDLH (immediately dangerous to life and health) atmospheres. It utilizes a hose (also called an airline) to deliver clean air from a stationary source of compressed air.
- SCBAs: These are the type worn by divers and firefighters. They have an open-circuit design that provides air rated for 30 to 60 minutes. The facepiece is tight fitting with a wearable clean air supply. They are used for short-duration work shifts or when entering atmospheres that are or may be IDLH.
- Combination SARs: These are airline devices used for extended periods in IDLH or non-IDLH atmospheres. An auxiliary self-contained air cylinder can supply air in case of failure of the primary air supply.
(Learn more in SCBA 101: Meet the Respirator That Will Save Your Life)
Air-Purifying Respirators (APRs)
Unlike SARs, air-purifying respirators do not supply air to the user. Instead, they filter out particulates and remove contaminants like dust, mists, and organic vapors.
These types of respirators are not to be used in IDLH atmospheres, oxygen deficient spaces, areas with hazardous levels of hydrogen sulfide (H2S), or the presence of other contaminants that are not suitable for an APR.
Air-purifying respirators are available in several types:
- Filtering Facepiece Respirators: These are disposable respirators that cover the nose and mouth to filter out dust, mist, and fumes. They do not protect against gases and vapors.
- Elastomeric Half Facepiece Respirators: These reusable respirators cover the nose and mouth. Their replaceable cartridges or filters can protect against gases, vapors, and particles.
- Elastomeric Full-Facepiece Respirators: These are reusable and protect the eyes, nose, and mouth. They provide a more effective face seal than other respirators. Their replaceable cartridges, canisters, or filters can protect against gases, vapors, or particles.
- Powered Air-Purifying Respirators (PAPRs): These have reusable components and replaceable cartridges, canisters, or filters. PAPRs protect the eyes, nose, and mouth from gases, vapors, and particles. These respirators are battery-powered and use a blower that pulls air through the filters or cartridges.
Selecting the Right Type of Respirator for the Job
When selecting a respirator, you may need to consult an industrial hygienist, an experienced safety professional, or a respirator manufacturer. The selection process, however, can be boiled down to two basic steps.
1. Assess the Hazards Workers May Be Exposed To
Identify all of the atmospheric hazards that a worker may encounter.
For example, if there is the potential for an oxygen deficient atmosphere or the presence of H2S, then a supplied air system will be required. If there are significant concentrations of dust, an air-purifying respirator will be required. In the case of vapors, workers may need to use a vapor cartridge.
An exposure assessment conducted by an industrial hygienist will determine exposure levels for the types of contaminants being tested. These levels are referenced against the ACGIH TLVs and BEIs booklets for the current year and the relevant OSHA requirements.
2. Determine the Level of Protection Required
Under OSHA, only respirators approved by the National Institute for Occupational Safety and Health (NIOSH) can be used in the workplace, and all NIOSH-approved respirators have an assigned protection factor (APF). The respirator's manufacturer or an industrial hygienist can help you determine the right level of protection.
Elements of Respiratory Protection in the Workplace
The following elements should be present in every workplace's respiratory protection program.
- Assess the hazards and evaluate other methods of controlling them
- Conduct an exposure assessment (if necessary)
- Develop a written respiratory protection program
- Conduct medical evaluations (where required)
- Perform qualitative or quantitative fit tests
- Provide the appropriate level of training to workers who will use respirators
To ensure optimal functioning, respirators must be used and maintained properly:
- All employees using respirators should be free of facial hair
- Employees must be encouraged to perform seal checks whenever they wear a respirator
- Respirators should be stored away from dust, sunlight, extreme temperatures, damaging chemicals, and excessive moisture
- Respirators must be cleaned and disinfected according to the manufacturer's specifications
- Respirators must be inspected for function, fit, the pliability of elastomeric parts, and the overall condition of the facepiece