Respirator Fit Tests

Safety Without Leaks 


A respirator fit test determines if a tight-fitting respirator can be worn without having any leaks. It should take place after an employee has been medically cleared to wear a respirator and before the employee wears it on the job. A respirator fit test is required for all tight-fitting respirators. Employees must complete the fit test using a respirator that’s the same make, model, and size as one they will wear on the job while also wearing any other required equipment (e.g., glasses).


    There are two kinds of respirator fit tests: qualitative and quantitative. Concentra® provides both.

    Qualitative Fit Testing (QLFT)

    • More common method
    • Normally used for half-mask respirators
    • Relies on the user’s senses 

    Quantitative Fit Testing (QNFT)

    • Uses a machine to numerically measure leakage into the facepiece

    Which fit test should be performed?

    Please answer the following questions.

    1. Is exposure greater than or equal to 10 times the permissible exposure limit (PEL)?
    2. Is the respirator for use in immediately dangerous to life or health (IDLH) environments (e.g., fires)?
    3. Is the respirator for exposures at unknown levels?
    4. Is fit testing for a fit factor of at least 500?

    A QNFT is required if the answer is “YES” to ANY of the questions above.

    A QLFT may be performed if the answer is “NO” to ALL four questions (even if the employee wears a tight-fitting, full-face mask).

    Other factors employers should consider include (but are not limited to):

    • Permitted if the respirator normally uses a powered/forced air supply and the powered/forced air is removed (i.e., the opening where the forced air connects to the mask is covered, normally with a filter)
    • Permitted to fit test negative-pressure, air-purifying respirators that must achieve a fit factor of 100 or less.
    • Required if assigned protection factor (APF) must be greater than 100
    • Required to test a full-face mask for a fit factor of 500 or more

    Concentra follows fit testing guidelines established by the Occupational Safety and Health Administration (OSHA) Respiratory Protection Standard 1910.134.

    Concentra recommends that employers follow the Small Entity Compliance Guide for the Respiratory Protection Standard to maintain OSHA compliance. 


    Concentra only conducts fit testing for employees wearing respirators certified by the National Institute for Occupational Safety and Health (NIOSH), such as N95 masks. N95 respirators are currently in full supply.

    Non-NIOSH certified respirators, such as KN95 masks, may be used for source control where respiratory protection is not needed, but they are not approved for fit testing.


    Respirator fit tests are a must for employees who are required to wear respirators to reduce exposure to hazardous chemicals or substances such as silica dust, welding fumes, paint spray mists, and solvents.