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A Guide on What to Expect When Having Face Fit Tests

If you work in an environment requiring respiratory protection, you may be familiar with the term ‘face fit tests’.

A face fit test ensures that the mask or respirator you are using fits your face properly, providing adequate protection.

If you’re new to the concept of a face fit test, here’s a step-by-step guide on what to expect during the process.

Trainer condusting face fit testing.

What is a Face Fit Test?

A face fit test is a method to determine if a particular mask or respirator fits the wearer’s face correctly.

It’s a legal requirement for employers to ensure employees’ protection from hazardous substances in the workplace.

The test is in place to ensure that the mask or respirator forms a tight seal around the face. This is to prevent any harmful substances from entering the wearer’s respiratory system.

Read our previous blog to learn what Face Fit Testing is.

Types of Face Fit Testing

The type of testing you require depends on the type of facepiece you have. The two types of tests that you could receive are:

Qualitative Fit Testing:

Qualitative testing assesses the effectiveness of a tight-fitting facepiece, such as a respirator, to ensure that it properly seals to the wearer’s face and provides the intended level of protection.

Unlike quantitative testing, qualitative testing relies on the wearer’s subjective response (taste) to the test agent, and it is a pass/fail test.

Quantitative Fit Testing (QNFT):

Quantitative face fit testing provides an objective numerical measurement of the fit of how well a facepiece seals against a wearer’s face.

This measurement is known as the ‘fit factor’. This is a ratio of the concentration of airborne particles inside the respirator to the concentration outside the respirator.

Quantitative fit testing is suitable for disposable and reusable half-masks and for full-face masks.

Examples of QNFT are:

  • Ambient particle counting
  • Controlled negative pressure (CNP)

The fit factor is calculated by the fit test equipment.

Arranging a Face Fit Test

Face fit testing needs to be carried out by a qualified tester.

It is important to make sure your tester is qualified by a reputable training provider. 3B Training has Fit2Fit accredited instructors to conduct Face Fit Testing and we even deliver Face Fit Train the Tester courses. This training course allows delegates to fit test within their organisations to comply with their legal requirements within the COSHH regulations.

You can also find out who is registered on the F2F Register.

The Fit Testing typically takes about 25 minutes per person to complete so it is important to allow time for the trainer to carry the test out. The test is easy to arrange you can do this by enquiring online. After enquiring, one of the team will then speak to you to schedule the test.

Pre-Test Preparation

Before the test, you will have to complete a questionnaire about your medical history and any previous experience with respiratory protection. This is to make sure that you are well enough to undergo the test and that there are no underlying health conditions that will affect the results.

Face Fit Pre Test Preparation

Testing Process

The test itself involves wearing a mask or respirator and performing a series of exercises to ensure that the mask fits correctly.

These exercises may include normal breathing, deep breathing, moving your head from side to side, up and down, bending at the waist and talking.

The tester will decide which tests to conduct based on what type of mask or respirator you have.

Here’s more information about each type of test:

Qualitative Fit Test

There are two common methods of qualitative tests, the Bitrex Test and the Saccharin Test.

  • Bitrex Test: This involves the introduction of a bitter-tasting aerosol (Bitrex) into the hood while the wearer performs a series of exercises. If the wearer can taste the bitter solution, it indicates that there is a leakage in the mask.
  • Saccharin Test: Similar to the Bitrex test, but it uses a sweet-tasting aerosol (saccharin) instead. If the wearer can taste the sweet solution, it suggests that there is a leak in the mask.

Quantitative Fit Test

  • Particle Counting (PortaCount) Test: This method uses specialised equipment, such as the PortaCount machine, to measure the concentration of microscopic particles inside and outside the respirator. The fit factor is calculated based on these measurements. This provides a numerical value for the fit and is more objective than qualitative testing.
  • Controlled Negative Pressure (CNP) Test: This method measures the pressure inside the facepiece during inhalation. The CNP test uses a specialised instrument to quantify the fit by comparing the pressure inside the mask to the ambient pressure.

To become a Face Fit Tester, book our Face Fit Train The Tester course.

Test Results

After the test, the tester will inform you if you have passed or failed.

If you pass, you will gain a certificate that confirms your mask’s suitability and the date of the test. This certificate is valid for two years and should be kept in a safe place.

If you have failed, the tester will provide you with guidance on how to improve the fit of your mask or recommend a different type of mask that may be more suitable for you.


Overall, face fit testing is an essential step in ensuring your safety in the workplace.

It is a simple and quick process that can provide peace of mind and protect you from harmful substances.

Following this guide gives you an idea of what to expect when having a face fit test, so you can confidently undergo the test.

Take a look at our Face Fit FAQs to learn more.

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