FFP1 vs FFP2 vs FFP3: EN 149 mask classes and how to choose a dust mask

FFP1, FFP2 and FFP3 values side by side

The table sets the class limits in the standard next to the assigned protection factors that the UK Health and Safety Executive (HSE) uses for selecting masks in the field.

The real gap shows up in two columns. On filter penetration, FFP2 and FFP3 look only five points apart. On inward leakage, the FFP3 limit is a quarter of the FFP2 limit. Much of what makes a mask FFP3 is how well it seals, not only what the filter media can catch.

The assigned protection factor (APF) is the minimum factor by which a mask, used properly, can be expected to cut the dust a person breathes. A 2% leakage limit works out at 50 on paper, but HSE uses 20 for FFP3 in the field. The sum is simple. Divide the measured concentration by the workplace exposure limit and pick a class whose APF is higher than the result. Six times the limit is within FFP2 (APF 10) on paper. Fifteen times needs FFP3. At 25 times no FFP class is enough, and the next step is equipment with an APF of 40, such as a full face mask with P3 filters.

Higher classes are allowed more breathing resistance: at 95 L/min, up to 2.1 mbar for FFP1 against 3.0 mbar for FFP3. In heavy work on a hot shift the difference can be felt. That is the case for issuing FFP3 where the hazard calls for it, rather than everywhere by habit.

Reading the markings: NR, R and D

On the mask or its packaging you will usually find a line such as EN 149:2001+A1:2009 FFP3 NR D, giving the standard, the class and the use markings in that order. The CE mark and the notified body number are printed nearby.

The D marking earns its keep in the dustiest jobs: concrete cutting, breaking out, emptying bags, mixing mortar. On a bulk order for that kind of work, put D in the specification; a mask without it may share the class but has not passed the clogging test.

One trap to watch. In the US approval system the letter R means oil-resistant; in EN 149 it means reusable. Where stock from both systems ends up on the same shelf, the same letter can be read two different ways.

• NR (non-reusable): for a single shift; the mask is discarded at the end of it.
• R (reusable): can be used for more than one shift, but only by following the manufacturer's cleaning and storage instructions.
• D (dolomite): passed the dolomite dust clogging test, showing breathing resistance stays within limits under a heavy dust load. Optional for NR masks, mandatory for R masks.

Valved or unvalved?

An exhalation valve only acts on the air you breathe out. It lowers exhalation resistance and lets heat and moisture escape from inside the mask. Protection for the wearer is held to the same limits as an unvalved mask, because valve leakage is already counted in the total inward leakage test. A valved FFP3 still has to meet the 2% limit.

The trade-off is that exhaled air leaves unfiltered. In food production, pharmaceutical filling or clean rooms, where the product has to be protected from the worker, unvalved masks are used.

The picture flips for heavy work in a hot foundry or on a building site in midsummer, where a mask stays on for hours. A mask that fills with heat and damp gets adjusted and lifted, and a valve reduces that. The question is who needs protecting: the worker alone, or the product as well.

Face fit, beards and fit testing

The ten people in the test laboratory are not your crew. That is why HSE expects every tight-fitting mask to be fit tested on the individual wearer as part of selection. Face shapes vary widely from person to person, between men and women and across ethnic groups, and one model in one size rarely fits a whole team.

There are two kinds of test. In a qualitative test, a bitter or sweet tasting aerosol is introduced into the air the wearer breathes; if they can taste it, the mask is leaking. A quantitative test counts particles inside and outside the mask and produces a fit factor. HSE's operational circular for inspectors, OC 282/28, gives 100 as the minimum pass level for filtering facepieces. A repeat test is needed after changes such as weight loss or gain or new scarring.

Facial hair is not negotiable. HSE's guidance on disposable masks is blunt: a mask that depends on face fit is useless if you have a beard or thick stubble, and a fit test should not be carried out with hair under the seal. For bearded workers the answer is loose-fitting powered equipment with a hood or helmet.

If a hard hat, safety glasses or ear defenders press on the edge of the mask, the fit test is done wearing them. Each time the mask goes on, the wearer also runs a quick check: nose clip pressed down, both straps in use, no air escaping at the edges. If a seal cannot be achieved, the mask is not used. For bulk buying, that is the argument for asking for two or three shapes and sizes rather than a single model. When requesting a quote from Formasan, giving the class, NR or R, the D marking, the valve preference and the number of shapes in one go settles the specification in the first exchange.

How long a mask lasts and when to change it

An NR mask is good for one shift. HSE's guidance on respiratory protective equipment, HSG53, defines that as eight hours, and the mask is discarded at the end of it, or sooner if it is heavily contaminated. A mask that is damaged, visibly dirty or noticeably harder to breathe through is replaced straight away. In very high dust concentrations that point comes quickly.

Eight hours of life is not eight hours of continuous wear. HSG53 recommends that unpowered tight-fitting masks are worn for less than an hour at a stretch, followed by a break. The reason is practical: a mask worn too long becomes uncomfortable, gets loosened or removed in the work area, and protection ends at that moment. Where a mask has to be worn all day, the guidance points to powered respirators or air-fed equipment with a hood or helmet.

A reusable R mask lasts as long as the manufacturer's instructions allow, and cleaning and storage follow the same instructions. Two site habits undo the protection. One is hanging a mask on a nail in a dusty area to use again the next day, which HSE specifically tells workers never to do. The other is wearing two dust masks on top of each other. According to HSE's asbestos guidance, doubling up gives no extra protection.

Choosing by dust type: silica, wood, welding fume, asbestos

A mask does not replace control at source. Turkey's regulation on the use of PPE in workplaces sets the order: the employer gives priority to collective protection, and PPE is used where the risk cannot be prevented that way. For dusty work, the Dust Control Regulation and the site risk assessment apply. Wet cutting and on-tool extraction reduce the load on the mask before anyone puts one on.

Welding fume moved up a level in 2019. HSE's expert committee endorsed the reclassification of mild steel welding fume as a human carcinogen, and a February 2019 safety bulletin changed what HSE expects: local exhaust ventilation for indoor welding and suitable RPE for welding outdoors. HSG53 does not recommend P1 or P2 against fume unless the manufacturer says otherwise, so FFP3 is the starting point for welding. The arc also forms ozone and nitrogen oxides from the air. Those are gases, and they pass straight through a particle filter.

With asbestos, look at the job before the mask. In Turkey, removal of asbestos-containing material falls under the Regulation on Health and Safety Measures for Work with Asbestos: it is carried out by trained removal workers under the supervision of an asbestos removal specialist, and a work plan is prepared and notified before work starts. The eight-hour limit for airborne asbestos is 0.1 fibres/cm³. For short, non-licensed work, HSE accepts FFP3 or a half mask with P3 filters, with hooded equipment for bearded workers and powered equipment for longer jobs.

Gas and vapour: where FFP stops and half masks take over

An FFP mask captures particles. Solvent vapour, ammonia, chlorine and acid gases go straight through. In an oxygen-deficient well, tank or sewer no filtering device may be used at all; that calls for breathing apparatus. Spray painting exposes the operator to paint mist and solvent vapour together, and HSE notes that particle filters are not effective against mist or spray of organic solvents either. An FFP mask is the wrong choice for that job.

The usual answer is a half mask with replaceable filters. The facepiece is certified to EN 140, particle filters to EN 143 and gas filters to EN 14387. A P3 particle filter may let through no more than 0.05%, a twentieth of the 1% allowed for FFP3 filter media. Even so, HSE gives a half mask with P3 filters the same APF as an FFP3, which is 20, because the face seal sets the ceiling. With a full face mask and P3 filters it rises to 40.

Gas filters are colour-coded. Brown A covers organic gases and vapours with a boiling point above 65 °C, grey B inorganic gases, yellow E sulphur dioxide and other acid gases, and green K ammonia and its organic derivatives. White P marks a particle filter. A combined marking such as A2P3 tells you the same cartridge handles organic vapour and dust.

Gas filters have a finite capacity. Once saturated, the gas passes straight through and the mask no longer protects. HSG53 therefore recommends a change schedule: capacity class 1 filters at least every two days, or daily against carcinogens and respiratory sensitisers, and class 2 filters at least once a week. Where the manufacturer gives a different interval, follow it.

FFP2 vs FFP3 vs N95

N95 is a US approval class issued by NIOSH under 42 CFR Part 84. The letter describes oil resistance and the number the minimum filter efficiency: N is not resistant to oil, R is resistant and P is oil-proof, with efficiency levels of 95%, 99% and 99.97%.

On paper N95 and FFP2 are close, and they are often sold as equivalents. The difference is in how they are tested. FFP classes are also challenged with an oily aerosol and with a leakage test on people, while the N series is restricted to workplaces free of oil aerosols. On a machining line where oil-based cutting fluid forms a mist, an N95 is therefore not the right mask. FFP3 and N99 share the same 99% headline figure, but the leakage test means the two cannot be matched one to one.

In Turkey, any PPE an employer issues must carry the CE mark and instructions for use in Turkish (Regulation on the Use of Personal Protective Equipment in Workplaces, Article 6). If a batch arrives with only an N95 print, ask for both.