There is no law called “the face fit testing regulations”, and the Health and Safety Executive’s own fit testing guidance says following it “is not compulsory”. Yet for almost anyone who wears a tight-fitting mask at work, a face fit test is effectively mandatory. The duty is indirect: the law says respiratory protective equipment (RPE) must be “adequate and suitable”, and the Approved Codes of Practice that sit under COSHH, the lead, asbestos, confined spaces and ionising radiations regulations all state that tight-fitting RPE should be fit tested before it is used. A mask that has not been fit tested cannot be shown to be suitable, so skipping the test puts an employer in breach of the main duty. Loose-fitting hoods and powered helmets are the exception: they do not need fit testing at all.
At a glance: Nexis CPD’s £9 Respiratory Protective Equipment (RPE) course explains how RPE fits into the control hierarchy, the difference between tight-fitting and loose-fitting RPE, why fit testing matters and how to carry out a pre-use seal check. It is CPD accredited and 100% online with a verifiable e-certificate, and any three courses cost £18. It is awareness training, not a regulated qualification.
Is face fit testing a legal requirement in the UK?
In practice, yes, for tight-fitting RPE. No single regulation uses the words “face fit test”, but the obligation is built into the health and safety law that governs hazardous substances. Regulation 7 of the Control of Substances Hazardous to Health Regulations 2002 (COSHH) requires every employer to ensure that exposure to substances hazardous to health “is either prevented or, where this is not reasonably practicable, adequately controlled”. Where RPE forms part of that control, regulation 7(9) says the equipment “shall be suitable for the purpose”.
The word “suitable” is where fit testing comes in. A tight-fitting mask can only protect the person wearing it if it seals against their face, and faces vary enormously in shape and size. The HSE puts it plainly: RPE “can’t protect the wearer if it leaks”, and “a major cause of leaks is poor fit”. A fit test is the recognised way of proving that a particular make, model and size of mask actually seals on a particular person. Without it, an employer cannot demonstrate that the RPE is suitable, and the control measure fails the legal test.
The detailed expectation is set out in the HSE’s current guidance document INDG479, “Guidance on respiratory protective equipment (RPE) fit testing” (October 2025 edition). It confirms that the Approved Codes of Practice (ACOPs) supporting COSHH, the Control of Lead at Work Regulations 2002, the Control of Asbestos Regulations 2012, the Confined Spaces Regulations 1997 and the Ionising Radiations Regulations 2017 all “stipulate that tight-fitting RPE should be fit tested as part of the selection process”.
That ACOP status matters. Following HSE guidance is not itself compulsory, but an ACOP has a special legal standing: if you are prosecuted for a breach of the regulations and you did not follow the relevant ACOP, a court will find you at fault unless you can show you complied with the law in some other, equally effective way. For fit testing, there is no realistic alternative way to prove a tight-fitting mask seals. So although you can search the statute book without ever finding the phrase, face fit testing is, for tight-fitting RPE, a genuine legal expectation rather than a nice-to-have.
What is face fit testing and why does it matter?
Face fit testing, also called RPE fit testing, is a check that a specific model and size of tight-fitting facepiece matches a wearer’s facial features and seals adequately to their face. INDG479 describes it as “a method for checking that a specific model and size of tight-fitting facepiece matches the wearer’s facial features and seals adequately to the wearer’s face”, adding that it “will also help to identify unsuitable facepieces which should not be used”.
The reason it matters is that an ill-fitting mask gives a false sense of security. The HSE warns that inadequate fit “will significantly reduce the protection provided to the wearer”, and that “any reduction in protection may lead to immediate or long-term ill health or can even put the RPE wearer’s life in danger”. Respiratory disease is one of the biggest causes of work-related ill health in Britain, and much of it is slow and silent: conditions such as silicosis, occupational asthma and asbestos-related disease can take years to show. A mask that leaks does not announce the fact. The worker breathes in contaminated air believing they are protected.
It is worth being clear about where RPE sits in the order of controls. Regulation 7(3) of COSHH sets out a hierarchy: first design out the hazard through better processes and engineering controls such as local exhaust ventilation, then control exposure at source, and only “where adequate control of exposure cannot be achieved by other means” provide “suitable personal protective equipment in addition to” those measures. RPE is the last line of defence, not the first. Fit testing makes that last line as reliable as it can be, but it never replaces extracting dust at source or using a less hazardous material.
Which regulations require RPE fit testing?
Fit testing is expected wherever tight-fitting RPE is used as a control measure under health and safety law. The regulations whose ACOPs call for it, as listed in INDG479, are:
- The Control of Substances Hazardous to Health Regulations 2002 (COSHH) — the main set, covering dusts, fumes, vapours, mists, gases and biological agents. This catches most workplaces, from woodworking and welding to cleaning and healthcare.
- The Control of Lead at Work Regulations 2002 (CLAW) — lead is not covered by COSHH and has its own regime, relevant to work such as stripping old paint, some soldering and battery work.
- The Control of Asbestos Regulations 2012 (CAR) — any licensed or notifiable non-licensed work with asbestos relies on RPE, and fit testing is a core part of it.
- The Confined Spaces Regulations 1997 — where breathing apparatus is used to enter a space with a hazardous atmosphere.
- The Ionising Radiations Regulations 2017 — for work with radioactive contamination where RPE is required.
The common thread is simple: if the law requires tight-fitting RPE to control a risk, the law also expects that RPE to have been fit tested. Our guide to COSHH regulations and employer duties sets out the wider control framework these fit tests sit inside, and our guide to workplace exposure limits (EH40) explains the airborne limits that RPE is often used to help meet.
Who needs a face fit test?
Anyone who relies on a tight-fitting facepiece to protect them from a hazardous substance needs a face fit test for that facepiece. Tight-fitting RPE, often just called masks, includes:
- Disposable half masks — the moulded filtering facepieces graded FFP1, FFP2 and FFP3.
- Reusable half masks — a rubber or silicone facepiece covering the nose and mouth, fitted with replaceable filters.
- Full-face masks — covering the whole face, used where higher protection or eye protection is needed.
- Tight-fitting powered respirators and breathing apparatus — these still seal to the face.
There is a widespread myth that powered RPE does not need fit testing because air is blown into it. INDG479 is explicit that this depends on the facepiece. “Powered or constant-flow airline BA RPE with loose-fitting hoods or helmets do not require fit testing”, but “tight-fitting powered or constant-flow airline BA RPE under positive pressure still requires fit testing as studies have shown that during heavy exertion, inward leakage is possible”. In other words, it is the seal that decides, not the power.
This is also the practical answer for people who cannot be clean-shaven, for medical, cultural or religious reasons: they should be given loose-fitting RPE, such as a powered hood or visor, which does not rely on a seal to the skin and therefore does not need a fit test. Nobody should be excluded from protection because of a beard; the right answer is different equipment, not no equipment.
Do I need to be clean-shaven for a face fit test?
For tight-fitting RPE, yes. This is the single most common reason fit tests fail, and the most common way protection is lost on site. The HSE states that being “clean-shaven when wearing tight-fitting masks (those which rely on a good seal to the face) will help prevent leakage of contaminated air around the edges”, and warns bluntly that “stubble and beards make it impossible to get a good seal of the mask to the face”.
The contrarian point worth absorbing is that this is not about a full beard. Even a day or two of stubble can break the seal along the line where the mask meets the skin, letting unfiltered air bypass the filter entirely. A worker can pass a fit test clean-shaven on Monday and be inadequately protected by Thursday simply because they have not shaved. That is why a fit test must be done on a clean-shaven face, and why a pre-use seal check should be carried out every single time the mask is put on, before entering the hazardous area.
That seal check is not the same as a fit test and does not replace it. INDG479 is clear: “a pre-use wearer-seal check is not a substitute for fit testing”. The fit test is the one-off proof that the model suits the person; the seal check is the routine, everyday confirmation that this particular wearing is sealed.
What is the difference between qualitative and quantitative fit testing?
INDG479 sets out two basic types of RPE fit testing, and which one you can use depends on the mask.
Qualitative fit testing (QLFT) is a pass or fail test based on the wearer’s sense of taste. The wearer puts on the mask, usually inside a hood, and a bitter- or sweet-tasting aerosol is introduced. If they cannot taste it while carrying out a set of exercises, the mask passes. The HSE notes that QLFT “is a pass/fail test based on the wearer’s subjective assessment of any leakage through the face seal region”. It is suitable only for disposable and reusable half masks; it is “not suitable for full-face masks”.
Quantitative fit testing (QNFT) gives a numerical result, called a fit factor, that measures objectively how well the mask seals. Common methods are ambient particle counting and controlled negative pressure. QNFT can be used for half masks and full-face masks alike, which is why full-face respirators must be tested this way. The fit factor is the ratio of the contaminant concentration outside the mask to the concentration measured inside it, so a higher number means a better seal.
Whichever method is used, the test only proves the mask can achieve the protection its grade promises. That protection is described by an assigned protection factor (APF): the workplace level of protection the facepiece is expected to provide. Using the figures in HSE guidance, an FFP1 disposable mask has an APF of 4, an FFP2 an APF of 10 and an FFP3 an APF of 20. A reusable half mask with a P3 filter also has an APF of 20, and a full-face mask with a P3 filter an APF of 40. The APF tells you which mask is adequate for the exposure; the fit test tells you it is suitable for the wearer. You need both.
How often do I need a face fit test, and does it expire?
Here is a point that surprises many employers: there is no legal expiry date on a face fit test, and no fixed interval written into any regulation. The common belief that a fit test “lasts two years” is an industry convention, not a statutory deadline.
What the law effectively requires is a system for deciding when a retest is needed. INDG479 says a fit test “should be carried out as part of the initial selection of the RPE”, and “should be repeated whenever there is a change to the RPE type, size, model or material, or whenever there is a change to the circumstances of the wearer that could alter the fit of the RPE”. The examples it gives are:
- weight loss or gain;
- substantial dental work;
- any facial changes, such as scars, moles or the effects of ageing, around the face seal area;
- facial piercings;
- the introduction of, or a change to, other head-worn personal protective equipment (PPE).
Beyond those triggers, the HSE says “it is good practice to have a system in place to review when a repeat fit test may be required”, noting that “face shape will change through ageing alone”. This is where the two-year rule of thumb comes from: the Fit2Fit accreditation scheme recommends repeat fit testing at a suitable interval of around two years, and many employers adopt that as a simple review cycle. Higher-risk work, such as licensed asbestos removal or healthcare tasks involving airborne pathogens, often uses shorter intervals. The key is that two years is a sensible default, not a legal ceiling: a change in the wearer’s face or a change of mask triggers a retest whenever it happens.
Who can carry out a face fit test?
A fit test must be done by a competent person. INDG479 says fit testing “should be conducted by a competent person”, and the HSE describes that person as someone “appropriately trained, qualified and experienced” in the specific method being used. A qualitative test relies on the tester running the procedure correctly and the wearer reporting honestly; a quantitative test relies on the tester operating the measuring equipment properly. Buying a fit testing kit does not make someone competent to use it.
There is no statutory licence for fit testers, but there is a recognised route to demonstrating competence. The HSE points employers towards the Fit2Fit RPE Fit Test Providers Accreditation Scheme, run by the British Safety Industry Federation (BSIF) with industry stakeholders and supported by the HSE. INDG479 notes that competence “can be demonstrated by accreditation under the Fit2Fit RPE Fit Test Providers Accreditation Scheme”, while stressing that the scheme “is not compulsory and employers are free to take other action to comply with the law”. Using a Fit2Fit-accredited tester is the simplest way to show you have met the competence expectation; it is not the only lawful way.
One more medical point sits alongside this. INDG479 warns that “some pre-existing medical conditions (for example breathing disorders such as asthma, skin allergies, or even heart problems) may restrict or prevent some workers wearing any RPE, or certain types of RPE”. Where there is doubt, the employer “should arrange for appropriate medical assessment”. Fit testing checks the seal; it does not check whether the person is medically able to wear the mask in the first place.
What happens if an employer skips fit testing?
Because fit testing underpins the “suitable” requirement in COSHH and its sister regulations, skipping it is not a technicality. If an employer provides tight-fitting RPE that has never been fit tested, they cannot show the equipment is suitable, which means the control measure does not meet regulation 7. HSE inspectors routinely check fit test records on dusty trades, in asbestos work and in manufacturing, and the absence of records is an obvious and common finding.
Enforcement can range from verbal advice and an improvement notice through to prosecution where exposure has caused, or risked, serious harm. But the real cost is usually the health outcome. A fit test takes around twenty to thirty minutes and a record lasts for years; a missed one can underlie a lifetime respiratory condition that no certificate can undo. Training the workforce so that everyone understands why the mask must seal, and reports stubble or a poor seal check, is part of the same duty. Our guide to the PPE at Work Regulations explains how RPE fits into the wider duty to provide and maintain protective equipment.
Which courses cover RPE and fit testing?
These three £9 courses work well together for anyone managing or using respiratory protection, each with a verifiable certificate:
- Respiratory Protective Equipment (RPE) — how RPE fits the control hierarchy, tight-fitting versus loose-fitting masks, fit testing and seal checks.
- COSHH Awareness — identifying hazardous substances, assessing exposure and choosing the right controls before RPE.
- Silica Dust Awareness — one of the most common reasons RPE and fit testing are needed on construction and stone-working sites.
Any three courses cost £18 with the pay-for-2-get-3 offer. Add them to the cart and the discount applies automatically. These are CPD accredited awareness courses that explain the law and good practice; they are not a substitute for a hands-on fit test by a competent person, and they are not regulated qualifications.
Frequently asked questions
Is face fit testing a legal requirement?
There is no regulation that names face fit testing, but for tight-fitting RPE it is effectively mandatory. COSHH and its sister regulations require RPE to be suitable, and the supporting Approved Codes of Practice say tight-fitting RPE should be fit tested as part of selection. A mask that has not been fit tested cannot be shown to be suitable, so skipping the test breaches the law.
Do I need to be clean-shaven for a face fit test?
Yes, for any tight-fitting mask. The HSE says stubble and beards make it impossible to get a good seal, and even a day or two of growth can let contaminated air leak past the filter. Workers who cannot be clean-shaven should be given loose-fitting RPE, such as a powered hood, which does not rely on a seal to the skin and does not need a fit test.
How often should a face fit test be repeated?
There is no legal expiry and no fixed interval in the regulations. A fit test is done at initial selection and repeated whenever the mask changes or the wearer’s face changes, for example through weight change, dental work, facial scarring, piercings or ageing. The Fit2Fit scheme recommends reviewing roughly every two years as good practice, with shorter intervals for higher-risk work.
What is the difference between qualitative and quantitative fit testing?
Qualitative fit testing (QLFT) is a pass or fail test based on whether the wearer can taste a bitter or sweet aerosol; it suits disposable and reusable half masks but not full-face masks. Quantitative fit testing (QNFT) gives a numerical fit factor using equipment such as a particle counter and can be used for half masks and full-face masks alike.
Does powered RPE need fit testing?
It depends on the facepiece. Loose-fitting powered hoods and helmets do not need fit testing. Tight-fitting powered respirators still do, because the HSE says inward leakage is possible during heavy exertion even under positive pressure. The seal decides, not the power supply.
Who can carry out a face fit test?
A competent person who is appropriately trained, qualified and experienced in the method used. There is no statutory licence, but the HSE points employers to the Fit2Fit accreditation scheme run by the BSIF as a recognised way to demonstrate competence. It is not compulsory, and employers may show competence another way.
Make sure the mask actually seals
£9 per course. CPD accredited, 100% online, verifiable e-certificate. Pay for 2, get 3 — any 3 courses for £18.
This article is general information, not legal advice. It summarises the Control of Substances Hazardous to Health Regulations 2002, the Control of Lead at Work Regulations 2002, the Control of Asbestos Regulations 2012, the Confined Spaces Regulations 1997, the Ionising Radiations Regulations 2017 and HSE guidance, in particular INDG479 “Guidance on respiratory protective equipment (RPE) fit testing”, as they apply at the time of writing. A fit test must be carried out in person by a competent person; an online course cannot replace it. For advice on a specific workplace or substance, consult a competent occupational hygienist or your enforcing authority. A Nexis CPD course is CPD accredited but is not a regulated qualification.