A respirator fit test confirms that a tight-fitting respirator forms an adequate seal against the wearer’s face. This seal is necessary for the respirator to properly filter airborne hazards, such as dust, fumes, gases, or pathogens, and prevent them from leaking into the mask. Since respirator sizes and shapes are not universal across different models and manufacturers, the test ensures that the specific device selected provides the expected level of protection for the individual.
The Regulatory Requirement
The need for a fit test is a legal mandate for employees in occupations where respiratory hazards are present, including construction, healthcare, and manufacturing. These requirements are established by regulatory bodies, such as the Occupational Safety and Health Administration (OSHA) in the United States, to protect worker health.
OSHA’s Respiratory Protection Standard requires that any employee using a tight-fitting respirator must be fit tested prior to initial use in the workplace. Testing must be repeated at least once every 12 months. An additional test is necessary whenever a physical change occurs that could affect the facepiece seal, such as significant weight gain or loss, major dental work, or using a different make, model, or size of respirator.
Common Testing Facilities
Individuals seeking a fit test have several options depending on their employment status and employer size. Occupational health clinics and urgent care centers are the most common public avenue for obtaining a test. These facilities specialize in workplace health services and have the necessary equipment and certified personnel to conduct both types of fit tests. Searching for “Occupational Health Services” or “Safety Compliance Testing” locally will typically yield a list of appropriate clinics.
Many larger companies, especially those with internal safety departments, provide employer-provided programs where testing is conducted on-site by a trained staff member. This internal option streamlines the process for employees and simplifies compliance for the organization. For companies with numerous employees or multiple worksites, mobile testing units offer a convenient, on-site solution. These units travel directly to the workplace, reducing employee downtime and allowing for large-scale compliance testing.
Necessary Preparations
Before a fit test can be administered, several mandatory steps must be completed to ensure the user can safely wear a respirator. The first requirement is obtaining medical clearance from a physician or other licensed healthcare professional. This medical evaluation, often a questionnaire or a Pulmonary Function Test (PFT), determines if the user is physically capable of wearing a respirator without undue health risk. The evaluation must be completed before the individual is fit tested or required to use the device on the job.
A second prerequisite is the strict requirement for being clean-shaven in the area where the respirator’s seal contacts the skin. Any growth of facial hair, even stubble, can interfere with the tight seal and allow contaminants to leak into the mask, invalidating the test. The law mandates that the sealing surface must be free of hair, which often means being clean-shaven within the previous 12 hours. Finally, the person being tested must bring the specific make, model, and size of the respirator they intend to use at work.
The Fit Test Procedure
The fit test procedure itself is conducted using one of two primary methods to verify the integrity of the respirator’s seal.
Qualitative Fit Testing (QLFT)
Qualitative Fit Testing (QLFT) is a pass/fail method that relies on the wearer’s senses. During this test, the individual wears the respirator under a test hood, and a substance that produces a strong taste or smell is introduced into the hood. Common test agents include saccharin, which has a sweet taste, or Bitrex, which is bitter. If the wearer detects the agent, it indicates a breach in the face seal, and the respirator fails the test. This method is typically used for half-mask respirators.
Quantitative Fit Testing (QNFT)
Quantitative Fit Testing (QNFT) is a more objective procedure that uses specialized equipment to numerically measure the amount of leakage. Instruments, such as a PortaCount device, connect to the respirator and measure the concentration of microscopic ambient particles outside the mask versus the concentration inside. The result is a numerical “fit factor” that objectively quantifies the seal’s effectiveness. QNFT is required for full-facepiece respirators.