Respirator fit testing is a safety procedure required by OSHA to ensure a respirator facepiece forms an adequate seal on the wearer’s face. The test determines if the respirator provides maximum protection from airborne contaminants by validating the seal and measuring potential leakage into the facepiece. A successful fit test qualifies an employee to use a specific brand/make/model and size of respirator.

A respirator fit test is conducted to validate the efficacy of a respirator or to determine the appropriate respirator for an employee’s protection on a work site or during a particular work activity. Because respirator sizing is not standardized across brands, a medium size in one model may not offer the same fit as a medium in another. It’s important to note that the OSHA respirator standard prohibits tight-fitting respirators from being worn by workers with facial hair that comes between the sealing surface of the facepiece and the face of the wearer, as this can interfere with the seal.

OSHA requires respirator users to be fit tested before use of a respirator in the workplace through two types of tests: Quantitative Fit Testing (QNFT) and Qualitative Fit Testing (QLFT).

Qualitative vs. Quantitative Fit Testing

Respirator fit testing is performed using two main methods:

• Qualitative Fit Test (QLFT): This is a pass/fail test that relies on the wearer’s senses (taste, smell, or a cough) to detect leaks in the mask’s seal. It is a common method for negative-pressure, air-purifying respirators.

• Quantitative Fit Test (QNFT): This test uses a special instrument to provide a numerical measurement of the exact amount of leakage in the mask’s seal. It offers an objective, data-driven result.

Medical Evaluations

OSHA states (1910.134(e)) using a respirator may place a physiological burden on employees that vary with the type of respirator worn, the job and workplace conditions in which the respirator is used, and the medical status of the employee. Before fit testing and use, an individual must provide a medical evaluation to gauge an employee’s ability to use a respirator. A physician or other licensed health care professional (PLHCP) must perform the medical evaluations.

How Often Should Fit Testing Be Done?

OSHA requires respirator fit testing to be conducted:

• Annually for all respirator users.
• Before a new hire begins using a respirator.
• When an employee changes to a new brand, model, or size of respirator.
• Whenever there are changes in an employee’s physical condition that could affect the respirator’s fit, such as weight change, dental changes, or facial scarring.

The necessity of these requirements has been confirmed by a NIOSH study. It is also important to note that OSHA has issued Temporary Enforcement Guidance for the Healthcare Industry that provides discretion for the annual fit test requirements as long as specific criteria are met.