Respiratory Protective Equipment (RPE) — Choosing and Using Dust Masks the Right Way (2026)

RPE Is the Last Line of Defence — Not the First

The single most important thing to understand about RPE is that it is the last resort, not the first. Under the Control of Substances Hazardous to Health Regulations 2002 (COSHH), you are legally required to control exposure at source before you reach for a mask. The hierarchy of control puts RPE at the very bottom for a reason: masks fail, slip, clog and get left in the van, whereas engineering controls work whether the wearer remembers them or not.

Work through the hierarchy first:

• Eliminate: can the dusty task be avoided altogether — buying pre-cut materials, ordering boards cut to size?
• Substitute: swap a high-hazard material or process for a lower-hazard one — a low-silica product, a paste instead of a powder.
• Engineering controls: on-tool dust extraction (LEV) fitted to cut-off saws, grinders and sanders; water suppression to damp down silica when cutting blocks or paving; local exhaust ventilation and general ventilation for fumes and vapours.
• RPE: only once exposure is reduced as far as reasonably practicable does RPE fill the remaining gap.

In practice, on-tool extraction or water suppression plus a well-fitted mask is the standard approach for silica-generating tasks. The mask alone is never the plan. For the full picture of the law around hazardous substances, see our guide to COSHH regulations for tradespeople and the specific risks of construction dust and silica.

Adequate AND Suitable — Both Words Matter

HSE uses two specific words when describing RPE that does its job: it must be both adequate and suitable. They are not the same thing, and equipment can be one without the other.

Adequate means the RPE provides the right level of protection for the hazard and the concentration of contaminant in the air. This is measured by the Assigned Protection Factor (APF) — the number of times the mask reduces the wearer's exposure when worn correctly. An APF of 20 means the air inside the mask is twenty times cleaner than the air outside it. You match the APF to how much you need to bring exposure below the Workplace Exposure Limit (WEL) for that substance.

Suitable means the RPE is right for the wearer, the task and the environment. A mask with a high APF is useless if it doesn't seal on that particular person's face, if it's too hot and heavy for an eight-hour job, or if it can't be worn with the other PPE the task demands. Suitability is about the human and the work, not just the number on the box.

The Main Types of RPE

RPE splits broadly into tight-fitting masks (which rely on a seal against the face) and loose-fitting devices (which don't). Here are the types you'll actually use on site.

Disposable Filtering Facepieces (FFP1 / FFP2 / FFP3)

These are the moulded, throwaway masks most people picture when they hear "dust mask". They are graded FFP1, FFP2 and FFP3 by the protection they offer:

• FFP1 (APF 4) — low-level nuisance dust only. Not adequate for most construction hazards.
• FFP2 (APF 10) — moderate dusts.
• FFP3 (APF 20) — high-risk dusts. This is the level needed for respirable crystalline silica from cutting concrete, brick, block and stone, and it is the common minimum requirement on construction sites for dusty work.

A genuine valved FFP3 is single-shift kit. Cheap, unbranded masks that don't carry a CE/UKCA mark and the EN 149 standard are not RPE — they are not adequate and won't protect anyone.

Reusable Half Masks and Full-Face Masks

Reusable masks have a rubber or silicone facepiece with replaceable filters that screw or clip on. A half mask with P3 particulate filters gives an APF of 20 — the same protection level as an FFP3 — but is more comfortable for repeated use and cheaper over time because you only replace the filters. A full-face mask covers the eyes too, gives a higher APF (typically 40), and is the choice where eye protection and a better seal are both needed.

The key advantage of reusable masks is the filter options. For dust you fit P3 particulate filters. But a particulate filter does nothing against solvent vapours, isocyanate paint mist or welding gases — for those you fit gas and vapour filters, identified by a letter and a colour: A (brown, organic vapours / solvents), B (grey, inorganic gases), E (yellow, acid gases) and K (green, ammonia). Spray painters typically need an A2-P3 combined filter; welders and demolition crews must match the filter to what's actually in the air.

Powered and Air-Fed Respirators (PAPR / Powered Hoods)

Powered air-purifying respirators (PAPR) use a battery-powered fan to draw air through a filter and deliver it to a hood, helmet or loose-fitting visor. Because they don't rely on a tight seal against the skin, they are the answer in two important situations: long-duration work where a tight mask would be too uncomfortable to keep wearing properly, and wearers who cannot get a face-fit — most commonly those with beards or stubble. Powered welding helmets with integrated respirators are now common for exactly this reason. They cost more, but for full shifts in heavy dust or fume they pay for themselves in protection actually delivered.

Face-Fit Testing Is Not Optional

Any tight-fitting mask — disposable FFP3 or reusable half/full-face — only works if it seals against the skin. Because every face is a different shape, a mask that seals perfectly on one person may leak badly on another. The law (COSHH) therefore requires that tight-fitting RPE is face-fit tested to the individual wearer, on the specific make and model they will use, before first use.

The make-or-break factor is facial hair. Stubble breaks the seal. Even a day's growth at the seal line lets contaminated air bypass the filter entirely, and no fit test will pass on an unshaven face. Wearers of tight-fitting masks must be clean-shaven where the mask meets the skin every time they wear it. If someone won't or can't shave, that's precisely when a loose-fitting powered respirator becomes the suitable choice.

Fit tests should be repeated if the wearer loses or gains significant weight, has dental work or facial changes, or switches to a different mask. Keep the results on record. We cover the process, qualitative versus quantitative methods and record-keeping in detail in our face-fit testing guide for trades.

Understanding Filter Ratings

Getting the filter wrong is one of the most common — and most dangerous — mistakes, because a mask that feels protective can be doing nothing at all against the actual hazard. Two separate systems matter:

• Particulate (P) filters stop dust, fibres and mist. They are rated P1, P2 and P3, with P3 the highest. For respirable silica and most construction dust you want P3.
• Gas and vapour filters are rated by letter and colour for the type of chemical they absorb — A (organic solvent vapours), B (inorganic gases), E (acid gases), K (ammonia) — and by a number (1, 2 or 3) for capacity.

The crucial point: a dust filter will not protect you against solvent vapours, and a gas filter will not protect you against dust. A painter spraying solvent-based finishes through a P3 dust filter has no protection at all from the vapour. Where a task generates both dust and vapour — sanding then spraying, for example — use a combined filter such as A2-P3 that handles both.

Use, Maintenance and Storage

RPE that lives crushed in the bottom of a dusty toolbag is RPE you can't trust. Looking after it properly is part of the legal duty, not housekeeping.

• Pre-use check, every time: inspect the facepiece, straps, valves and filters for damage before you put it on. Then do a fit check (seal check) each time you don the mask — cover the filters and breathe in, or exhale gently, to confirm the seal holds.
• Replace disposables when due: a disposable FFP3 is single-shift. Bin it when it's clogged, damaged, wet or breathing becomes hard, and at the end of each shift.
• Clean reusable masks: wipe down the facepiece after use and clean it thoroughly to the manufacturer's schedule. Don't let dust build up inside.
• Replace filters on time: particulate filters when breathing resistance rises; gas/vapour filters when you can taste or smell the contaminant, or per the manufacturer's service life — whichever comes first.
• Store clean and dry: keep masks in a clean, dry, sealed container away from dust, sunlight and solvents — not loose in the van.
• Keep records: maintain records of maintenance, inspections and face-fit tests. For non-disposable RPE these records should be kept and available to show you're managing the kit.

Training the Wearer

A mask handed over with no instruction is a false sense of security. Anyone wearing RPE must be trained in how to fit it correctly, how to carry out the fit check each time, how to recognise when filters or the mask itself need replacing, and how to clean and store it. Training is a COSHH requirement, and it's also what turns expensive kit into actual protection. Supervisors should be checking that masks are worn correctly on site — a mask pulled down to the chin or worn over a beard protects no one.

Quick Reference: RPE Types vs Typical Use

The Bottom Line

RPE works only when it's the right type, sealed to the wearer's face, fitted with the correct filter, maintained, and worn properly every time. Control dust and fumes at source first, choose RPE that is both adequate and suitable, fit test every tight-fitting mask, train your wearers, and keep your records. Get those right and you protect the most valuable thing in your business — the people doing the work, and your own lungs.