Maintenance & systems
Respirators sit below extraction, not beside it. Under COSHH, LEV and other controls come first, and RPE is the last line for the exposure left over - and a tight-fitting mask only works if it seals, which is why the law expects face-fit testing by a competent person, and a clean-shaven face, every time it is worn.
The short answer
Respirators sit below extraction, not beside it. Under COSHH, LEV and other controls come first, and RPE is the last line for the exposure left over - and a tight-fitting mask only works if it seals, which is why the law expects face-fit testing by a competent person, and a clean-shaven face, every time it is worn.
The detail
Respiratory protective equipment is not an alternative to LEV - it is what covers the exposure that engineering control cannot. COSHH sets an order: prevent exposure if you can, then control it at source with measures like extraction, and only then, for the residual risk that remains, reach for RPE. A respirator worn instead of fixing or fitting proper extraction inverts that order and leaves the workplace relying on the weakest link in the chain, worn on individual faces, rather than the strongest.
That matters because RPE is fragile in a way extraction is not. Regulation 7 requires RPE to be adequate and suitable, and for a tight-fitting mask 'suitable' means it actually seals to the individual wearing it. People's faces differ so much that no single mask fits everyone, and a facepiece that leaks provides a false sense of safety while letting contaminant straight into the breathing zone. The seal, not the filter, is usually where protection is lost.
This is why the law expects face-fit testing. The Approved Codes of Practice supporting COSHH require tight-fitting facepieces to be fit tested as part of selection, by a competent person - competence often evidenced through the Fit2Fit scheme. HSE guidance HSG53 covers selecting and maintaining RPE, and INDG479 sets out the fit-test methods: qualitative 'taste test' methods for disposable and half masks, and quantitative instrument-based testing, which is required for full-face masks. The test is specific to one make, model and size, and must be repeated if the mask or the wearer's face changes.
A good fit test is undone by a poor daily habit. Tight-fitting masks only seal on a clean-shaven face, so stubble breaks the seal however well the test went - which is why clean-shaven is required both at the test and every time the mask is worn. Where someone cannot shave, loose-fitting powered hoods that do not rely on a face seal are the alternative. And a pre-use seal check each time is expected, though it never replaces the formal fit test.
What it means for you
Set against LEV, RPE should be the smaller part of the control story, not the whole of it. If a workplace finds itself depending on respirators for routine work, that is usually a sign the extraction needs reviewing - a hood repositioned, a system repaired, or new LEV fitted - so that engineering control does the heavy lifting and RPE covers only what is genuinely left over, or short tasks where fixed extraction is impractical.
Where RPE is used, it carries its own duties: proper selection for the hazard and the wearer, fit testing at the start and on any change, training in how to wear and check it, storage and maintenance, and records of the fit tests kept and available for inspection. The employer meets the cost of all of it. These are real obligations, and they are lighter to carry when RPE is the exception rather than the frontline.
The clean way to think of it is layered: extraction captures the hazard at source, the residual is caught by a respirator that has been proven to seal on the person wearing it, and both are documented. Get the extraction right and RPE becomes a modest, well-run backstop. Lean on RPE instead of the extraction, and you are trusting the whole of control to a seal on a face - which is exactly what the hierarchy is designed to avoid.
The service behind the guide
Sibling guides
Keeping LEV working all year between tests · Daily and weekly checks staff can run · Why LEV quotes differ site to site
Questions
No. COSHH puts engineering controls like extraction first and treats RPE as the last line for residual exposure. Relying on respirators instead of proper LEV inverts the hierarchy and trusts control to a face seal.
Because it only protects if it seals to the individual's face, and faces vary. Regulation 7 requires RPE to be suitable, and the supporting Approved Codes of Practice require tight-fitting masks to be fit tested by a competent person.
Qualitative is a 'taste test' suitable for disposable and half masks; quantitative uses instruments to measure leakage and is required for full-face masks. INDG479 sets out both methods.
Yes. Tight-fitting masks only seal on a clean-shaven face, so stubble breaks the seal. Clean-shaven is required at the test and every time the mask is worn; those who cannot shave need loose-fitting alternatives.
The employer. Fit testing, suitable RPE, training and the associated records are all the employer's responsibility and cost under COSHH.
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