Comparison · Respiratory protection
FFP2 filters at least 94% of test particles; FFP3 at least 99%. That five-point gap sounds small and isn't — in protection-factor terms FFP3 is roughly twice the mask, and for the dusts that end careers (silica, hardwood, welding fume) it's the specified answer, not the upgrade option.
The difference
Both are disposable filtering facepieces under EN 149; the rating is filtration efficiency against the standard's test aerosols — FFP2 ≥ 94%, FFP3 ≥ 99% — which translates in UK practice to assigned protection factors of roughly 10 and 20: worn correctly, the air inside carries a tenth or a twentieth of the contaminant outside. The choice is made by the hazard's toxicity, not preference: respirable crystalline silica (concrete cutting, chasing, quarry dust), hardwood dusts (a carcinogen — see the joinery sector guide), and welding fume (now treated as carcinogenic across the board) are FFP3 territory in almost every competent assessment. FFP2 holds the line for general nuisance-to-moderate dusts — plastering finish work, softwood offcuts, general sweeping.
The uncomfortable truth both ratings share: the number assumes a sealed fit. Stubble, the wrong size or a casually-donned mask leaks around the edges, and leakage doesn't care about filter grade — which is why face-fit testing is a legal expectation for tight-fitting RPE at work, and why an FFP2 that fits beats an FFP3 that doesn't.
The decision
| Hazard | Rating | Why |
|---|---|---|
| Silica dust (concrete, stone, brick) | FFP3 | Silicosis is dose-driven and irreversible — the assessment will say FFP3 |
| Hardwood dust | FFP3 | Carcinogen — sinonasal cancer risk |
| Welding fume | FFP3 minimum | Reclassified carcinogenic; extraction first, RPE with it |
| Plaster, softwood, general dusts | FFP2 | Moderate-hazard dusts at typical exposures |
| Composite/GRP sanding | FFP3 common | Fine respirable fibre — see the Hull composite trades |
The caveats
Questions
Meaningfully, yes: minimum filtration rises from 94% to 99%, and the assigned protection factor doubles from about 10 to 20. For carcinogenic and high-toxicity dusts — silica, hardwood, welding fume — FFP3 is the specified rating, not a luxury upgrade.
Whenever the risk assessment's exposure maths demands a protection factor of 20 — in practice, silica-generating tasks (cutting concrete, stone, brick), hardwood dust, welding fume and similar high-hazard aerosols. The assessment and any trade guidance name it; extraction and wet-cutting still come first in the control hierarchy.
No — FFP masks are tight-fitting and seal against skin, and even heavy stubble leaks enough to undo the rating. Facial hair points to loose-fitting powered RPE (hoods) instead. For clean-shaven wearers, face-fit testing verifies the seal the rating depends on.
Both sides of every comparison are one click away — or ask a human to settle it for your team.