Face Fit Testing for UK Trades — RPE, Tight-Fitting Masks and the Law (2026)

What Is RPE — and What Needs Fit Testing?

RPE is the category of equipment that protects the wearer's airways from harmful dust, fumes, vapours or gases. It splits into two broad types, and the distinction matters because only one of them needs a face fit test.

Tight-fitting RPE relies on a seal between the facepiece and the skin. This includes disposable filtering facepieces (FFP1, FFP2 and FFP3 masks — the throwaway moulded ones), reusable half masks that cover the nose and mouth, and full face masks. Because protection depends entirely on that seal, and because every face is a different shape, tight-fitting RPE must be face fit tested for each individual wearer.

Loose-fitting RPE does not rely on a tight seal. Powered hoods, helmets, visors and air-fed blouses deliver a flow of clean air into a loose enclosure, so a perfect skin seal isn't required. This equipment does not need a face fit test — which is one practical reason many trades with beards move to powered hoods.

Is Face Fit Testing a Legal Requirement?

Yes. Where tight-fitting RPE is used to control exposure to a hazardous substance, face fit testing is a legal requirement — not best practice or a nice-to-have. The duty sits under several sets of regulations depending on what you're exposed to:

• Control of Substances Hazardous to Health (COSHH) Regulations 2002 — the main regime, covering silica dust, wood dust, fumes and most hazardous substances.
• Control of Lead at Work Regulations 2002 — where work disturbs lead, such as old paintwork, leaded pipework or lead flashing.
• Control of Asbestos Regulations 2012 — for any licensed or non-licensed work that may disturb asbestos-containing materials.

Under all three, the employer must ensure RPE is suitable and that tight-fitting facepieces fit the wearer. A face fit test is the recognised way of demonstrating that fit. The Health and Safety Executive (HSE) treats it as a clear expectation, and inspectors routinely ask to see fit test records on site. If you're self-employed, the duty still applies to you — you're responsible for your own RPE being suitable and tested.

The Two Test Methods: Qualitative vs Quantitative

There are two accepted approaches to face fit testing, and the right one depends on the type of mask.

Qualitative testing (the taste test)

A qualitative test relies on the wearer's sense of taste. The person puts the mask on, a hood is placed over their head, and a bitter or sweet test agent — usually Bitrex (denatonium benzoate) or saccharin — is sprayed into the hood. While performing a set of exercises (normal breathing, deep breathing, turning the head, talking, bending), the wearer reports whether they can taste the agent. If they can, the mask is leaking and the fit has failed. The result is a simple pass or fail — there's no number.

Qualitative testing is only valid for disposable filtering facepieces and reusable half masks. It is not acceptable for full face masks, because the higher protection those masks claim cannot be confirmed by a pass/fail taste check. A failed sensitivity check beforehand (where the person can't taste the agent at all) means qualitative testing can't be used for that individual.

Quantitative testing (the particle counter)

A quantitative test uses a machine — most commonly a PortaCount — that measures the concentration of particles outside the mask versus inside it, while the wearer performs the same kind of exercises. The output is a numerical fit factor: a higher number means a better seal. The mask passes only if the fit factor meets the required threshold for that class of RPE.

Quantitative testing can be used for any tight-fitting mask, and it is required for full face masks. Because it produces an objective number rather than relying on the wearer's perception, many employers use it across the board for a more robust record.

The Clean-Shaven Rule

This is the one that catches people out. A tight-fitting mask cannot seal against facial hair. Even a day or two of stubble where the seal sits will break the seal and let unfiltered air leak in — and the leakage is significant, not marginal. For this reason the wearer must be clean shaven in the area where the mask seals, both at the time of the test and every single time the mask is worn afterwards.

A fit test passed on a clean-shaven face is meaningless if the person then turns up to work with three days' growth. If a worker won't or can't be clean shaven — for medical, religious or personal reasons — the answer is not to ignore it. The answer is loose-fitting RPE such as a powered hood or visor, which doesn't depend on a skin seal and doesn't require a fit test. Plan this in before the job, not on the morning of it.

Who Can Carry Out a Fit Test?

A face fit test must be carried out by a competent person — someone with the training, knowledge and experience to perform the test correctly and interpret the result. The HSE doesn't mandate a specific qualification, but the recognised benchmark across the industry is the Fit2Fit accreditation scheme. A Fit2Fit-accredited tester has been independently assessed as competent, and using one is the simplest way to demonstrate to an inspector or principal contractor that your testing is credible.

You can train an in-house person to test, or bring in a mobile testing provider who comes to your yard or site. On larger jobs, many principal contractors will only accept fit test certificates from a Fit2Fit tester, so it's worth asking before you turn up.

How Long Does It Take and What Does It Cost?

A single face fit test typically takes around 20 to 30 minutes per person, per mask model, including the exercises and the paperwork. Costs vary by provider, location and whether you're testing one person or a whole crew, but as a rough guide expect somewhere in the region of £25–£60 per person for a standard test, with on-site group bookings and quantitative tests usually toward the higher end. Treat these figures as indicative — always get a current quote, because rates differ between mobile providers and fixed testing centres.

When Do You Need to Retest?

A face fit test is specific to one person wearing one make and model of mask. You need a fresh test whenever anything changes that could affect the seal:

• A different mask model — switching brand, model or size means the previous test no longer applies. A pass on one FFP3 does not transfer to another.
• Significant weight change — gaining or losing a noticeable amount of weight alters the shape of the face and the seal.
• Facial changes — scarring, major dental work or anything that changes the contours where the mask sits.
• Good practice intervals — even with no changes, it's widely recommended to repeat fit testing periodically (many employers work to roughly every two years, or more often in higher-risk work) to confirm nothing has drifted.

Record-Keeping

Keep a record of every fit test. As a minimum it should show the name of the person tested, the make, model, type and size of the mask, the test method used, the result (and the fit factor for quantitative tests), the date, and the name of the tester. These records are what you produce when the HSE or a principal contractor asks for evidence that your RPE is suitable — and a clear, retrievable record is the difference between a quick check and a difficult conversation on site. Storing fit test certificates alongside your other compliance documents in Trade2Base keeps everything in one place, so when a tester's certificate or retest is due you're not digging through a glovebox or a phone gallery to find it.

Common Mistakes

• Testing on the wrong mask. A worker is tested on one model, then buys a cheaper or different one to use on site. The fit test is invalid the moment the model changes.
• Beards and stubble. Passing a test clean-shaven, then wearing the mask unshaven, defeats the entire purpose. The seal is broken and protection drops away.
• No records. A test that isn't documented can't be evidenced. If there's no certificate, as far as an inspector is concerned the test didn't happen.
• Treating qualitative as universal. Using a Bitrex taste test on a full face mask isn't acceptable — those need a quantitative test.
• Never retesting. A fit test from five years ago, after a weight change and a new mask, tells you nothing about today.

The Bottom Line

Face fit testing is one of the cheapest and most effective pieces of compliance a dust-exposed trade can do. It costs a few pounds and half an hour, and it's the only thing that proves the mask between your lungs and the silica actually works. Use a competent — ideally Fit2Fit — tester, match the method to the mask, stay clean shaven where the seal sits (or move to a powered hood), retest when things change, and keep the paperwork. Logging your testing and renewal dates in Trade2Base means the records are there when you need them, not lost when it matters most.