Respirator Fit Testing
May 19, 2020
OSI offers both on-site and off-site respirator fit testing.
Respirator fit testing is necessary to determine if the respirator is properly donned (put on) to be effective. Particles can penetrate gaps of respirators that do not completely seal around the face. Many factors can influence the efficacy of the respirator such as the shape or size of the user’s face, facial hair, respirator material, and more. It is important to note that respirators vary in sizes from manufacturer to manufacturer. The fit test should be performed with the same make, model, style, and size that will be utilized. This is a Cal/OSHA requirement and can be found in Subsection 5144 - Respiratory Protection. A small 3M N95 may not fit the same as a small North N95 respirator. This also means that if a person is fit tested with a 3M N95 but switches to another manufacturer then a subsequent fit test must be performed.
How are fit tests conducted?
Fit tests must be conducted using either a Qualitative fit test (QLFT) or Quantitative fit test (QNFT). Qualitative fit tests are conducted using a pass/fail method based on the individual’s response to test agents. This type of testing can be thought of as a taste test.
Quantitative fit tests assess the adequacy of the respirator using numerical values. The respirator is evaluated by measuring particles on the outside of the respirator (environment) and on the inside of the respirator (what you breathe in).
Which test is preferred?
Quantitative fit tests are preferred as the test gives us a value on how well the respirator can filter particles when donned on the individual. Quantitative fit tests directly compare the concentration of particles on the inside and outside of the mask and do not rely on the individual’s ability to taste.
Qualitative fit tests rely on the individual’s ability to taste the selected solution, which is often a bitter or sweet solution. If an individual cannot detect the solution than the test cannot be performed. It also relies on the individual to report the detection of the solution.
Is fit testing required? What else is required?
Fit testing is required when employers require the use of respirators. If respirators are voluntarily used, then fit testing is not required unless the respirator is a half-face respirator or full-face respirator. In addition to fit testing, the following are necessary when respirators are required, or a half-face or full-face respirator is used:
- Medical clearance to wear a respirator
- A written respirator protection program
- Respiratory protection training (annually)
Respirators should still be fit tested even if they are used voluntarily. Using a respirator improperly can give the user a false sense of protection leading to an increased chance of exposure.