A tight-fitting respirator only protects the person wearing it if air cannot get past the seal. Faces differ, masks differ, and the only way to know a particular mask seals on a particular face is to test it.
That is what face fit testing is, and it applies to every tight-fitting facepiece — disposable FFP masks included. It is not reserved for expensive equipment.
What respiratory protection do your people wear?
If it seals against the face, it needs fit testing
Where the requirement comes from
COSHH regulation 7 requires exposure to be prevented or adequately controlled, and where RPE forms part of that control it must be suitable for the wearer and the work. A mask that leaks is not adequate control, so the duty to ensure it fits follows directly.
Equivalent requirements apply under the Control of Asbestos Regulations 2012 and the Control of Lead at Work Regulations 2002.
The assigned protection factor of a mask — the figure that makes it look adequate in your assessment — assumes a good seal. Without a fit test, the number in your COSHH assessment is an assumption rather than a control.
When fit testing is required
- Before first use. Not after a few weeks — before the person relies on it.
- When the make, model or size changes. A pass on one mask does not transfer to another.
- After significant facial change — weight loss or gain, dental work, facial surgery or a scar affecting the seal area.
- Periodically, as a check that the fit is maintained and the wearer still dons it correctly. Many organisations retest every two years, and annually for higher-risk work.
Fit testing must be done on the wearer's own mask — the same make, model and size they will actually use. Testing on a sample from the training room and issuing something different afterwards invalidates the whole exercise.
Facial hair
This is the point that causes the most friction, and there is no way to soften it: stubble or a beard in the seal area prevents a tight-fitting mask from sealing.
It is not about grooming standards or appearance. Hair in the seal zone creates channels that contaminated air travels through, and no amount of tightening the straps closes them. Someone who shaved yesterday may already have enough regrowth to fail.
A mask worn over facial hair gives the wearer the confidence of protection without the protection. That is worse than no mask at all, because it removes the caution that would otherwise apply.
Where a seal cannot be achieved
A worker who cannot or will not be clean-shaven in the seal area is not a problem without a solution, and it need not become a disciplinary matter.
Loose-fitting powered RPE — hoods, helmets and visors — does not rely on a face seal. It requires no fit test, accommodates facial hair, and is often more comfortable for long wear. Where someone keeps a beard for religious reasons, this is the answer, and providing it avoids a discrimination problem as well as an exposure one.
Tight-fitting RPE
- •Disposable FFP, half masks, full face masks
- •Relies entirely on a face seal
- •Fit testing required for each wearer
- •Defeated by facial hair in the seal area
- •Cheaper per unit
Loose-fitting powered RPE
- •Hoods, helmets and visors with a blower
- •No face seal to defeat
- •No fit test required
- •Works with facial hair
- •Higher up-front cost, needs battery and filter management
Fit testing is not an RPE programme
Passing a fit test is one component. RPE only works in practice if the rest is in place:
- The right RPE selected for the substance and the exposure level
- Wearers trained to don, check and remove it correctly
- A pre-use seal check every time it is worn
- Maintenance, cleaning and filter changes on a defined schedule
- Storage that does not deform the facepiece
- Supervision confirming it is actually worn during the task
RPE sits at the bottom of the hierarchy of control. Before relying on it, the question is whether the dust or fume could be eliminated, substituted, or captured at source by extraction — see LEV and dust control.
Common mistakes
Assuming disposables are exempt. Any tight-fitting facepiece needs a fit test.
Testing once and never again. Faces change, and so do the masks you buy.
Testing on a different mask from the one issued. The result applies to that make, model and size only.
Tolerating stubble. A seal either exists or it does not.
Treating a fit test as the RPE programme. Selection, training, seal checks and maintenance all sit alongside it.
Where this fits
See HSG53 — Respiratory protective equipment at work for HSE's guidance on selection and use, COSHH for the assessment RPE sits inside, and workplace exposure limits for the figures your protection factor is measured against. Where exposure remains after controls, see occupational health for health surveillance.