A tight-fitting respirator — an FFP disposable mask, or a reusable half or full-face mask — only protects the wearer if it seals against their skin. Face fit testing is a check that a specific mask, on a specific person, achieves that seal. Under COSHH (and related regulations), it is expected wherever tight-fitting respiratory protective equipment is used.
Why faces and masks both vary
People have different face shapes and sizes, and masks are not one-size-fits-all. A mask that seals perfectly on one person may leak on another, letting unfiltered air bypass the filter entirely. Fit testing matches the right make, model and size of mask to each wearer before they rely on it.
The two test methods
- Qualitative — a pass/fail test relying on the wearer's sense of taste. A bitter or sweet solution is sprayed into a hood; if they cannot taste it, the mask passes. Suitable for disposable (FFP) and reusable half masks only.
- Quantitative — uses a particle-counting machine to measure leakage and produce a numerical "fit factor". Required for full-face masks, and usable for any tight-fitting mask.
Clean-shaven means clean-shaven
Facial hair where the mask seals breaks the seal — no amount of fit testing fixes stubble under the rubber. Wearers of tight-fitting masks must be clean-shaven at the seal on the day. Where that is not possible, consider loose-fitting powered respiratory protection, which does not rely on a face seal.
When to re-test
- When someone is issued a different make, model or size of mask.
- After significant facial changes — notable weight change, dental work or scarring.
- Periodically as good practice (many employers repeat roughly every two years).
General guidance only. Use a competent tester (the Fit2Fit scheme accredits providers) and follow current HSE guidance for your situation.