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N95 Fit Testing Requirements for Healthcare Staff

Nurses, CNAs, and other staff who must wear an N95 at work fall under OSHA's respiratory protection standard, 29 CFR 1910.134. The rule says a worker needs a medical evaluation before a fit test, and a fit test before first use. For agency staff, OSHA says the staffing agency and the hospital share responsibility. This guide covers what the rule requires and what records to keep.

Updated October 3, 2026 · Checked against official CDC and OSHA sources

Who the rule covers

When respirators are needed to protect workers' health, or when the employer requires them, the employer must have a written respiratory protection program with worksite-specific procedures (1910.134(c)(1)).

Workers who use a tight-fitting facepiece respirator must pass a fit test (1910.134(f)(1)). OSHA defines a filtering facepiece (the type an N95 is) as a negative pressure particulate respirator where the filter is part of the facepiece or the whole facepiece is filter material. In a 2002 letter about filtering facepiece respirators, OSHA said the fit test must be done before the respirator is used at work.

Step 1: medical evaluation before the fit test

The employer must provide a medical evaluation to find out if the worker can use a respirator. This must happen before the worker is fit tested or required to use the respirator (1910.134(e)(1)).

A physician or other licensed health care professional (PLHCP) does the evaluation. They use a medical questionnaire, or an exam that gets the same information (1910.134(e)(2)).

The rule lists when an additional medical evaluation is needed (1910.134(e)(7)):

The worker reports medical signs or symptoms related to their ability to use a respirator.
A PLHCP, supervisor, or the program administrator tells the employer the worker needs to be reevaluated.
Program information, including what was seen during fit testing, shows a need for reevaluation.
Workplace conditions change in a way that may greatly increase the physical burden on the worker.

Step 2: when a fit test is required

Under 1910.134(f)(2), a worker using a tight-fitting respirator must be fit tested at these times:

Before first use of the respirator.
Whenever a different respirator facepiece is used. OSHA lists this as a different size, style, model, or make.
At least once a year after that.
Whenever the worker reports, or the employer, PLHCP, supervisor, or program administrator sees, changes in physical condition that could affect fit (1910.134(f)(3)). OSHA's training materials give examples: facial scarring, dental changes, cosmetic surgery, or an obvious change in body weight.
If the worker later says the fit is unacceptable, they must get a reasonable chance to pick a different facepiece and be retested (1910.134(f)(4)).

Qualitative vs. quantitative fit tests

The fit test must use an OSHA-accepted protocol. The accepted protocols are in Appendix A of the standard (1910.134(f)(5)).

A qualitative fit test is a pass/fail test. It relies on the worker's response to a test agent, such as a taste or smell. OSHA's training materials list isoamyl acetate, saccharin, Bitrex, and irritant smoke protocols.

A quantitative fit test uses an instrument to measure how much air leaks into the respirator. It gives a number called a fit factor.

Qualitative tests may only be used for negative pressure air-purifying respirators that must reach a fit factor of 100 or less (1910.134(f)(6)). A quantitative test is passed with a fit factor of at least 100 for a tight-fitting half facepiece, or at least 500 for a full facepiece (1910.134(f)(7)).

Fit test records

The employer must keep a record of each fit test (1910.134(m)(2)). Fit test records must be kept until the next fit test is given.

Medical evaluation records are different. They must be kept and made available under OSHA's medical records rule, 29 CFR 1910.1020 (1910.134(m)(1)). That rule generally requires keeping medical records for at least the length of employment plus 30 years. It has an exception for workers employed less than one year if the records are given to the worker when they leave.

Name or ID of the worker tested.
Type of fit test performed.
Make, model, style, and size of the respirator tested.
Date of the test.
Pass/fail result for qualitative tests, or the fit factor and test recording for quantitative tests.

Staffing agency vs. hospital: who does what

OSHA's Temporary Worker Initiative Bulletin No. 8 covers respiratory protection. It says the host employer and the staffing agency "are jointly responsible to ensure workers wear appropriate respirators when required." The two employers may decide to divide the work.

OSHA says the host employer will usually have primary responsibility for evaluating exposures and running the respiratory protection program, because it controls the worksite. The staffing agency "shares responsibility" and must take reasonable steps to protect its workers. That includes knowing the respiratory hazards at the site, the protections in place, and the site's respirator requirements.

OSHA also says neither the host nor the staffing agency can make workers provide or pay for their own respirators when they are required.

For medical evaluations, the bulletin says a written recommendation from an earlier host's or agency's PLHCP may be accepted only if the work conditions and type of respirator stay the same, it fits the new worksite, and it meets 1910.134(e)(1). The bulletin also says the two employers should agree on who keeps the medical records before work begins.

Put each party's duties (medical evaluation, fit testing, training, records) in the contract before the first shift.
Ask each facility which N95 make, model, style, and size it uses. A different facepiece means a new fit test.
Neither employer can shift its legal duties away by contract. OSHA says neither may avoid its ultimate responsibilities by requiring another party to perform them.

Training every year

Fit testing is only one part of the program. Workers must also be trained on why the respirator is needed, its limits, how to put it on and take it off, how to check the seal, and how to store it (1910.134(k)(1)). Retraining must be given every year, and also when certain changes happen (1910.134(k)(5)).

Common questions

How often does a nurse need an N95 fit test?

Before first use, at least once a year after that, whenever a different facepiece (size, style, model, or make) is used, and whenever a change in physical condition could affect fit. This is 29 CFR 1910.134(f)(2) and (f)(3).

Does a worker need a medical evaluation before a fit test?

Yes. OSHA requires a medical evaluation of the worker's ability to use a respirator before the worker is fit tested or required to use one (1910.134(e)(1)).

If a hospital uses a different N95 model than the worker was tested on, is a new fit test needed?

Yes. The rule requires a fit test whenever a different respirator facepiece (size, style, model, or make) is used. The fit test record must list the make, model, style, and size tested, so compare it to what the facility uses.

How long do we keep fit test records?

Until the next fit test is given (1910.134(m)(2)). Medical evaluation records follow OSHA's medical records rule, 29 CFR 1910.1020, which has much longer retention.

Is the staffing agency or the hospital responsible for fit testing?

OSHA says both are jointly responsible. The host usually has the main role because it controls the worksite, but the agency must take reasonable steps to protect its workers. The two can split duties in their contract.

Can a worker be charged for their N95 or fit test?

OSHA's temporary worker bulletin says neither the host nor the staffing agency can require workers to provide or pay for their own respiratory protection when it is required.

Sources

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