The Definition of Qualitative Fit Test (QLFT)

Definition of Qualitative Fit Test (QLFT)

A qualitative fit test is a pass/fail method of checking whether a tight-fitting respirator seals properly to a worker's face. The worker wears the respirator inside a hood or test area while a test agent is introduced. If they can taste, smell or react to the agent, air is leaking around the seal and the test fails. If they cannot detect it through a series of exercises, the respirator passes.

OSHA's Respiratory Protection Standard (29 CFR 1910.134, Appendix A) accepts four qualitative protocols: isoamyl acetate (banana oil, which can only test organic vapor cartridges), saccharin (sweet taste), Bitrex (bitter taste) and irritant smoke. Because the result depends on the wearer's response, a qualitative test can only be used for respirators that need a fit factor of 100 or less.

Key Facts About Qualitative Fit Testing

• QLFT is allowed for negative-pressure air-purifying respirators, such as half masks and N95 filtering facepieces, that must achieve a fit factor of 100 or less.
• Full facepiece respirators used in atmospheres that need more protection must be tested with a quantitative fit test instead.
• Workers must be fit tested before first use, at least annually and whenever the respirator model, size or the worker's face changes significantly.
• The test includes a sensitivity check first to confirm the worker can detect the agent at all.
• Facial hair that crosses the sealing surface prevents a valid fit test.

Example of a Qualitative Fit Test

A new construction worker will wear an N95 during concrete cutting. The fit tester first confirms he can taste a weak Bitrex solution. He then puts on the N95 under a hood and performs exercises such as normal and deep breathing, turning his head, moving his head up and down, talking and bending over, while the Bitrex is sprayed into the hood. He never tastes the bitter agent, so he passes for that make, model and size.

How to Run a Qualitative Fit Test Program

1. Include fit testing in your written respiratory protection program.
2. Make sure each worker has medical clearance before fit testing.
3. Choose an OSHA-accepted protocol suitable for the respirator type.
4. Run the sensitivity test, then the full exercise sequence for each respirator model and size.
5. Record the worker, respirator, protocol, date and result, and schedule the annual retest.

Related Terms

• Quantitative Fit Test (QNFT)
• Fit Testing
• Respiratory Protection
• N95 Respirator
• Assigned Protection Factor (APF)

Qualitative Fit Test Frequently Asked Questions

What is the difference between qualitative and quantitative fit testing?

A qualitative test is pass/fail and relies on the worker detecting a test agent. A quantitative test uses an instrument to measure leakage and produces a numerical fit factor, so it does not depend on the worker's senses.

Is a user seal check the same as a fit test?

No. A user seal check is a quick positive and negative pressure check the worker does every time they put on the respirator. A fit test is a formal test done before first use and at least annually.

Can someone with a beard pass a fit test?

Not with a tight-fitting respirator if facial hair comes between the face and the seal. Workers who cannot be clean-shaven in the seal area can use loose-fitting respirators such as some PAPRs.

Does a fit test pass for one respirator cover others?

No. A pass applies only to the specific make, model, style and size tested. Switching to a different respirator requires a new fit test.