“Face fit testing can feel like a mystery if you’ve never been through one.”

People often worry about whether they’ll “taste chemicals”, whether the machine will hurt, or whether they can fail because they’ve shaved badly that morning.

In reality, a face fit test is a straightforward, practical check that confirms whether a respirator actually seals to your face. It follows a recognised fit-testing protocol set out in HSE guidance and usually takes no more than 20–45 minutes.

This guide sets out exactly what happens before, during and after a face fit test – whether you’re having a qualitative (“taste test”) or quantitative (instrument-based) assessment.

Quick Answer: What does a face fit test involve?

A face fit test checks whether a specific tight-fitting respirator forms an effective seal on an individual wearer. The tester checks the mask, confirms the wearer is clean-shaven in the seal area and guides them through a series of breathing, talking and movement exercises while leakage is assessed using either a qualitative taste test or a quantitative instrument.

The result applies only to the exact make, model and size of mask tested.

Key takeaways

  • Face fit testing checks whether a tight-fitting respirator properly seals to an individual’s face.
  • Tests follow approved qualitative (“taste test”) or quantitative (instrument-based) methods under HSE INDG479.
  • Workers must be clean-shaven in the seal area for tight-fitting RPE; stubble, beards and some moustaches will cause a fail.
  • The mask used in the test must be the exact make, model and size worn on the job – changing any of these requires a new test.
  • A full test includes breathing and movement exercises, plus a pre-use mask check and a user seal check.
  • Qualitative tests use a bitter or sweet aerosol and give a simple pass/fail.
  • Quantitative tests use an instrument (e.g., Portacount) to produce a numerical fit factor and detect very small leaks.
  • Employers should keep clear fit test records identifying the wearer, facepiece, method, result and tester.
  • A passed test does not replace daily user seal checks or proper RPE maintenance.
  • Workers who cannot achieve a seal may need loose-fitting hoods or helmets instead of tight-fitting masks.

Jump to

Why a face fit test is needed

Tight-fitting RPE only works if the seal stays intact. Even small leaks let contaminated air bypass the filter and be inhaled.

Because people’s faces differ – and so do mask shapes, sizes and models – no respirator can be assumed to fit. A face fit test provides documented evidence that the chosen model is suitable for the wearer and that they can put it on correctly.

Loose-fitting hoods and helmets do not require face fit testing, because they rely on a flow of clean air rather than a tight seal. They still need to be correctly selected, used and maintained under your RPE programme.

Who should have a face fit test?

Any worker who relies on tight-fitting RPE as part of your control measures under COSHH and related regulations should be fit tested, for example:

  • Engineers using FFP2/FFP3 masks in dusty or contaminated areas
  • Maintenance staff using half masks with filters
  • Staff wearing full-face masks for higher hazard work

Agency staff and contractors who use tight-fitting masks under your control measures still need suitable fit testing; how you arrange it is a practical and contractual question.

What does a face fit test check?

A face fit test checks whether a specific tight-fitting respirator can form and maintain an adequate seal on the individual wearer’s face.

It does not test the worker’s lung function, diagnose a medical condition or prove that every mask will fit them.

The test looks for:

  • Facepiece suitability: Whether the make, model and size are compatible with the wearer’s facial shape.
  • Seal integrity: Whether contaminated air could leak between the face and the mask seal.
  • Fit during movement: Whether the seal remains effective while the wearer breathes, talks, turns their head, looks up and down and bends or steps.
  • Correct fitting: Whether the wearer can put the respirator on, adjust it and position the straps correctly.
  • Compatibility with other PPE: Whether glasses, goggles, helmets, visors or other equipment interfere with the seal or straps.
  • Mask-specific performance: Whether that exact make, model, size and configuration achieves the required result for that wearer.
Important: A face fit test is different from a medical FIT test used for bowel screening. In workplace safety, fit testing refers to checking the seal of tight-fitting respiratory protective equipment.

What happens before the test

A competent tester will go through several checks before the fit test begins.

1. A short health and suitability questionnaire

This confirms the worker is medically suitable for the mask type (for example, no unmanaged respiratory issues) and that they understand what will happen during the test.

If someone has a known allergy or asthma, the tester may need to adjust the method or use quantitative testing instead of a taste-based test.

2. Confirming the mask model, size and filters

The mask used during the test must be identical to the one the worker will actually wear at work:

  • Same make and model
  • Same size
  • Same filter or cartridge type

Using a different size, model or brand invalidates the result and means another test is required.

3. Clean-shaven requirement (tight-fitting masks only)

HSE is clear: stubble, beards and facial hair in the seal area prevent a reliable fit and will cause the test to fail.

For tight-fitting masks:

  • Workers must be clean-shaven in the seal area on the day
  • Beard nets, barriers or mask liners cannot be used to “get around” this
  • Workers who cannot shave normally need suitable loose-fitting RPE instead

4. Pre-use RPE check

The tester inspects the mask to make sure it’s safe and suitable:

  • Straps and buckles
  • Face seal condition
  • Valve condition (for half/full-face masks)
  • Filter compatibility and expiry

The wearer is also shown how to don the mask correctly and carry out a user seal check – the simple check they should perform every time they put the mask on.

Interaction with other PPE

Any PPE normally worn with the mask (for example safety glasses, visors or helmets) must be worn during the test. Eye protection that breaks the seal or interferes with strap placement will cause the test to fail, so compatibility is assessed at this stage.

5. Preparation rules for the wearer

To get a valid result, most qualitative test protocols ask the wearer to:

  • Avoid smoking or vaping for at least 1 hour before testing
  • Avoid eating, chewing gum, sweets, mints or flavoured drinks for 15–30 minutes
  • Avoid strong flavours (mints, coffee, spicy food) immediately before a taste test
  • Be well enough to take part (no acute respiratory illness)

For qualitative tests, the wearer also needs a normal sense of taste. If their sense of taste is significantly reduced (for example due to illness or medication), a quantitative method is usually more appropriate.

Qualitative “hood” testing may not be suitable for some people with asthma or certain respiratory conditions. If the wearer cannot tolerate aerosols, is pregnant, or has respiratory conditions that make hood testing unsuitable, a quantitative method is normally used instead.

What happens during a face fit test

There are two recognised methods – both valid under HSE INDG479.

Qualitative vs quantitative face fit testing

Both methods check whether a respirator fits the individual wearer, but they assess leakage in different ways and are suitable for different facepieces.

Fit Test Method How It Works Suitable For Result
Qualitative face fit testing A bitter or sweet aerosol is introduced inside a hood while the wearer completes the test exercises. Detecting the taste indicates leakage. Disposable filtering facepieces and reusable half masks, subject to the test method and required protection level. Pass or fail.
Quantitative face fit testing An instrument measures leakage or the concentration of particles inside and outside the facepiece while the wearer completes the exercises. Disposable masks, reusable half masks and full-face masks, depending on the quantitative method used. Numerical fit factor and pass or fail.

The appropriate method depends on the mask type, required protection and the wearer’s circumstances.

1. Qualitative face fit testing (QLFT) – “taste test”

This is a pass/fail test used for:

  • FFP1/FFP2/FFP3 disposable masks
  • Reusable half masks

It is not suitable for full-face masks.

The sensitivity test

  • Before the mask goes on, the wearer sits under a test hood without RPE.
  • A bitter or sweet aerosol solution (commonly Bitrex for bitter or saccharin for sweet) is sprayed into the hood.
  • The tester records how many sprays it takes for the wearer to taste it.
  • This establishes the wearer’s sensitivity level.

More detail on the solutions used

The solutions used in qualitative testing contain either:

  • Denatonium benzoate (“Bitrex”) – bitter
  • Saccharin – sweet

The sensitivity solution is a weaker concentration used to confirm that the wearer can detect the taste. If they cannot taste it even after 30 squeezes, a qualitative method is not suitable and a quantitative test is required.

The tester will also check the nebuliser is working by removing the intake/exhaust covers and confirming a visible mist before testing begins.

The fit test

The wearer puts the mask on correctly and repeats a standard sequence of exercises under the hood:

  • Normal breathing
  • Deep breathing
  • Turning head side to side
  • Moving head up and down
  • Talking (for example reading a short passage)
  • Bending or stepping
  • Normal breathing again (optional)

If the wearer can taste the solution at any stage, the test fails and the mask is unsuitable for them.

More detail on the exercise protocol

  • The qualitative protocol follows seven standard exercises lasting around one minute each.
  • Every 30 seconds the tester recharges the hood with additional aerosol to maintain a consistent concentration.
  • The talking exercise normally uses the Rainbow Passage (an industry-standard text) but counting backwards from 100 is an acceptable alternative.
  • If the nebuliser stops emitting a visible mist at any point, the test must be restarted for accuracy.

2. Quantitative face fit testing (QNFT) – instrument-based

Suitable for:

  • Disposable FFP masks
  • Reusable half masks
  • Full-face masks

This method uses an instrument such as a Portacount to measure the ratio of particles inside vs outside the mask.

How it works

  • The mask is connected to the instrument via a small sampling tube.
  • The wearer completes the same series of exercises as in the qualitative test.
  • The machine continuously samples air inside the mask.
  • It calculates a fit factor for each exercise and an overall fit factor.
  • The overall fit factor must meet or exceed the required level for the specific mask type.

Why employers choose QNFT

  • It provides objective, numerical evidence.
  • It is the recognised method for full-face masks.
  • It can detect small leaks that may not be picked up by taste tests.
  • It avoids reliance on the wearer’s sense of taste.

Mask variability and leak detection

A major advantage of quantitative testing is its ability to detect very small leaks – including those caused by:

  • Facial hair or stubble
  • Certain mask designs that fit inconsistently across face shapes
  • Hard or narrow face seals
  • Movement that disrupts the seal

Some masks can produce excellent fit factors on one wearer and very low scores on another. Quantitative testing prevents false “passes” that can happen with poorly fitted models.

What happens after the test

The fit test isn’t the end of the process – it’s the point where you finally find out whether the mask you’ve chosen actually works for that person. What happens next is simple: you get a clear pass/fail decision, a compliant report, and practical guidance to keep your team using their RPE correctly day-to-day.

1. Pass or fail explained clearly

The tester will explain the result straight away.

  • Pass: That specific make, model, size and configuration of mask is suitable for that wearer.
  • Fail: The mask does not seal adequately; another model or size is required.

It is common for some people to try more than one mask before finding a good fit. If a wearer fails repeated tests on a particular style, they may need to move to a different mask design or, in some cases, a loose-fitting system.

2. Issuing the fit test report

A compliant face fit test report normally includes:

  • Wearer’s name and role
  • Mask make, model, size and filters
  • Test method used (qualitative/quantitative)
  • Fit factor (for quantitative tests)
  • Pass/fail decision
  • Date of test
  • Recommended retest interval
  • Name of the fit tester and organisation

Employers should retain fit test records as part of their RPE management arrangements and in accordance with the applicable health and safety requirements.

3. Advice on daily use

A successful fit test does not remove the need for good day-to-day practice. Workers still need to:

  • Put the mask on correctly every time
  • Carry out a user seal check each time they don the mask
  • Store and maintain the RPE properly
  • Report any damage or issues immediately

4. Decontamination & hygiene

For qualitative tests, the hood and nebulisers must be cleaned between uses:

  • Disposable masks used during testing should be discarded afterwards.
  • Wearers should wash hands, face and (if applicable) hair to remove residual solution.
  • The hood interior should be wiped with a suitable disinfectant.
  • Nebulisers are usually rinsed or soaked to remove crystallised solution.
  • Equipment must be fully dry before the next test.

This helps prevent cross-contamination and ensures accurate results for the next wearer.

How long does a face fit test take?

Typical durations are:

  • Qualitative tests: around 20–30 minutes per person
  • Quantitative tests: around 30–45 minutes per person

Extra time may be needed if the wearer has to try more than one mask model or size.
For large teams, employers usually book half-day or full-day on-site sessions so several staff can be tested in sequence without disrupting operations.

How employers can prepare for a smooth session

You’ll avoid most delays and retests if you:

  • Ensure staff who use tight-fitting RPE are clean-shaven in the seal area on the day
  • Bring all mask models actually used on site, with the right filters
  • Standardise RPE models where possible, so fewer different masks need to be tested
  • Prepare health questionnaires in advance
  • Allocate a quiet, well-ventilated room with tables and chairs
  • Provide access to water, mirrors and any other PPE (goggles, helmets, visors) staff normally wear with their masks
  • Stagger appointment times to prevent queues and keep people on schedule

Well-prepared teams get faster tests, fewer failures and more reliable results.

Need Face Fit Testing for Your Team?

If you’d like support choosing the right masks, carrying out on-site face fit testing, or building a reliable RPE programme, our team can help. Velocity Safety test workers across construction, manufacturing, facilities management, logistics and more – including full-day workplace visits for larger teams.

📞 Call: 01254 933 486
📩 Email: info@velocitysafety.co.uk
🌐 Or book face fit testing online

Face fit testing FAQs

These are some of the most common questions about what happens during a face fit test, how the results are assessed and what workers need to do before testing.

What is a face fit test?

A face fit test checks whether a specific tight-fitting respirator forms an adequate seal on an individual wearer’s face.

The wearer completes a series of breathing, talking and movement exercises while leakage is assessed using either a qualitative taste test or a quantitative instrument.

What does a face fit test look for?

A face fit test looks for leakage between the respirator seal and the wearer’s face.

It also checks whether the mask remains correctly positioned while the wearer breathes, talks, turns their head, looks up and down and moves during the test exercises.

Why must RPE be face fit tested?

Tight-fitting RPE cannot provide the expected protection if contaminated air leaks around the face seal rather than passing through the filter.

Because facial shapes vary, an employer cannot assume that one make, model or size of respirator will fit every worker. Fit testing confirms whether the selected facepiece is suitable for the individual wearer.

Does a face fit test hurt?

No. Face fit testing is non-invasive.

Some people find the hood, aerosol taste or mask slightly uncomfortable, but neither qualitative nor quantitative testing should be painful.

Will the taste test make me ill?

The sweet or bitter solutions used during qualitative face fit testing are introduced at low concentrations and are used to indicate whether the mask is leaking.

Most people only notice the taste if the face seal is not effective. Anyone with asthma, respiratory sensitivities or concerns about the test solution should tell the tester before the assessment begins.

What do they spray during a face fit test?

Qualitative face fit tests use either a sweet saccharin solution or a bitter denatonium benzoate solution, commonly known as Bitrex.

The solution is introduced as an aerosol inside the test hood. If the wearer tastes it while wearing the respirator, the mask has leaked and the test is failed.

What happens during a qualitative face fit test?

The wearer first completes a sensitivity test without the respirator to confirm they can detect the test solution.

They then put on the mask and test hood before completing a sequence of breathing, talking and movement exercises. If the wearer detects the sweet or bitter taste during the test, the facepiece has not maintained an adequate seal.

What happens during a quantitative face fit test?

The respirator is connected to a fit-testing instrument using a sampling tube or suitable adaptor.

The instrument measures leakage while the wearer completes the required exercises and produces a numerical fit factor. The result must meet the required pass level for the type of facepiece being tested.

Do I need to be clean-shaven for a face fit test?

Yes, where facial hair would sit beneath or cross the seal of a tight-fitting respirator.

Stubble, beards, sideburns and some moustaches can prevent an effective seal. Workers who cannot be clean-shaven may need suitable loose-fitting respiratory protection that does not rely on a face seal.

What happens if someone fails a face fit test?

A failed result means the tested make, model, size or configuration did not provide an adequate fit for that wearer.

The tester may:

  • Check the wearer’s fitting technique and strap position.
  • Try another size in the same mask range.
  • Test a different make or model.
  • Recommend a loose-fitting hood or helmet if tight-fitting RPE cannot achieve a suitable seal.

The worker should not rely on the failed facepiece for respiratory protection.

Can one face fit test cover several mask types?

No. The result applies only to the exact make, model, size and configuration tested.

A separate face fit test is required if the worker changes to a different mask model, size or type of tight-fitting facepiece.

Can full-face masks be tested qualitatively?

No. Full-face masks require a suitable quantitative fit-testing method.

Qualitative taste testing is used for eligible disposable filtering facepieces and reusable half masks, subject to the required protection level and test protocol.

How long does a face fit test take?

A face fit test commonly takes around 20 to 45 minutes per person.

The exact time depends on the test method, mask type and whether the wearer needs to try more than one size or model before achieving a suitable fit.

How long does a face fit test remain valid?

There is no single expiry period that applies in every situation.

A repeat test should be arranged if the wearer changes mask make, model, size or material, or if facial changes could affect the seal. Employers may also set periodic retesting requirements within their RPE programme.

When should a face fit test be repeated?

Face fit testing should be repeated when:

  • The wearer changes to a different make, model, size or type of tight-fitting facepiece.
  • The wearer experiences significant weight change, dental work, facial surgery or scarring.
  • The wearer reports difficulty obtaining a seal.
  • The mask design or material changes.
  • The employer’s RPE programme or relevant sector guidance requires reassessment.

Does a passed face fit test replace a user seal check?

No. The wearer must still complete a user seal check every time the respirator is put on.

The face fit test confirms that the selected facepiece can fit the wearer. The user seal check helps confirm that it has been fitted correctly on that particular occasion.

What should a face fit test record include?

A face fit test record should identify:

  • The wearer.
  • The exact make, model and size of facepiece tested.
  • The test method used.
  • The test result.
  • The date of testing.
  • The tester and organisation completing the assessment.
  • The fit factor where quantitative testing is used.

Employers should retain these records as part of their wider RPE management arrangements.

Can I carry out my own face fit tests?

Face fit testing must be completed by someone competent in the test method, equipment, recognised protocol and interpretation of results.

Some employers train suitable staff to carry out internal testing. Others use a competent external face fit testing provider. Fit2Fit accreditation is a recognised way for a tester to demonstrate competence.

Can face fit testing be completed on-site?

Yes. Velocity Safety provides on-site face fit testing for individual workers and larger teams.

The employer should provide a suitable testing area, ensure workers are prepared and make sure the exact masks and other PPE used at work are available.

Next steps for UK employers

If you need support with fit testing, RPE selection or wider respiratory protection measures, see:

Resources & Legislation

If you want to check the formal rules behind face fit testing and RPE, here are the authoritative sources:

  • HSE INDG479 – Face Fit Testing Guidance (rev2, 2025) – The official guidance covering qualitative and quantitative methods.
  • HSE HSG53 – Respiratory Protective Equipment at Work – Detailed guidance on selecting, using and maintaining RPE.