Respirator guide
Respirator fit testing
An assigned protection factor only applies if the respirator actually seals to the wearer’s face — which is what fit testing verifies.
When fit testing is required
OSHA 29 CFR 1910.134 requires that every employee using a tight-fitting respirator (half mask or full facepiece) pass a fit test before first use, at least annually, and again whenever the respirator model or size changes or the wearer’s face changes. Loose-fitting respirators such as PAPR hoods and helmets do not require fit testing.
Qualitative fit test (QLFT)
A pass/fail test relying on the wearer’s sensory detection of a challenge agent — irritant smoke, saccharin (sweet), Bitrex (bitter), or isoamyl acetate (banana odor). QLFT is permitted only for respirators with an APF of 10 or less (for example half masks and filtering facepieces).
Quantitative fit test (QNFT)
An instrument (ambient-aerosol condensation nuclei counter, generated aerosol, or controlled negative pressure) measures a numerical fit factor. QNFT is required for negative-pressure full-facepiece respirators and any time a measured fit factor is needed. Passing fit factors: ≥100 for half masks and ≥500 for full facepieces.
Facial hair and the seal
Facial hair that crosses the sealing surface prevents a reliable seal and will fail a fit test — no assigned protection factor can be claimed. Workers with facial hair typically need a loose-fitting PAPR or hood instead.
Related
Fit testing determines whether the respirator you selected will actually deliver its APF. Use the calculator to choose a respirator class, then compare types in APR vs PAPR vs SCBA. Reference only — follow your written respiratory-protection program and OSHA 1910.134 Appendix A.
How often is respirator fit testing required?
OSHA 29 CFR 1910.134 requires fit testing for tight-fitting respirators before first use, at least annually thereafter, and whenever there is a change in the respirator model/size or the wearer’s face (weight change, dental work, scarring).
What is the difference between qualitative and quantitative fit testing?
A qualitative fit test (QLFT) is pass/fail based on the wearer detecting a test agent by taste, smell, or irritation — allowed for respirators with an APF of 10 or less. A quantitative fit test (QNFT) uses an instrument to measure a numerical fit factor and is required for negative-pressure full-facepiece respirators or whenever a measured fit factor is needed.
What fit factor is a passing result?
Under OSHA’s protocols, a quantitative fit test passes at a fit factor of at least 100 for half-mask respirators and at least 500 for full-facepiece respirators.