In brief
Under TS EN 149, the maximum total inward leakage for FFP1, FFP2 and FFP3 masks is 22%, 8% and 2%; in other words, FFP3 lets through about four times less dust than FFP2. The right class is found from the ratio of the measured dust concentration to the limit value and from the type of dust; FFP3 is preferred for carcinogenic dusts such as hardwood dust. A mask marked "NR" is for a single shift and is replaced sooner if breathing becomes difficult, or if it gets wet or damaged.
What do the FFP classes describe?
The protection class of disposable dust masks, known in the standard as filtering half masks against particles, is determined according to TS EN 149. To understand the difference between FFP2 and FFP3 and which class to choose for which dust, you first need to look at what the classes measure. The standard sets two separate limits for each class: how many particles the filter lets through, and how much air in total enters unfiltered while the mask is worn, including leakage between the face and the mask.
| Class | Particle penetration through the filter (max.) | Total inward leakage (max.) | Nominal protection factor (100 / inward leakage) | Assigned protection factor set by HSE |
|---|---|---|---|---|
| FFP1 | 20% | 22% | About 4.5 | 4 |
| FFP2 | 6% | 8% | About 12.5 | 10 |
| FFP3 | 1% | 2% | 50 | 20 |
The nominal protection factor is calculated from the worst acceptable leakage in the laboratory. In the field, a mask never fits as well as in the laboratory; that is why the HSG53 guidance of the UK Health and Safety Executive (HSE) uses lower assigned protection factors for selection: 4 for FFP1, 10 for FFP2 and 20 for FFP3. Turkish legislation has no separate table published for this purpose; the HSE values are a good reference for a cautious choice.
The markings on the mask are also informative: NR means single-shift use, R means reusable, and D shows that the mask has passed the clogging test with dolomite dust.
What does the difference between FFP2 and FFP3 mean in practice?
The difference between FFP2 and FFP3 is 8% versus 2% total inward leakage: a correctly fitted FFP3 lets through about four times less dust than an FFP2. A simple calculation is used to determine which will be sufficient:
Required protection factor = concentration measured in the workplace ÷ occupational exposure limit value
The measurement value in the calculation cannot be a guess. We plan workplace measurements with authorised laboratories and health institutions; the result is entered into the risk assessment and the mask is chosen accordingly.
Choosing a dust mask by type of dust
The table below is a practical guide that can be used as a starting point in the risk assessment until the measurement results arrive. The final choice is made through measurement and the risk assessment.
| Dust or job | Example | Recommended minimum class |
|---|---|---|
| Low-toxicity, coarse dust | Sweeping, packaging dust, short exposure to plaster and lime dust | FFP1 or FFP2 |
| Wood dust (softwood, MDF, chipboard) | Cutting, routing, sanding | FFP2; FFP3 for intensive sanding |
| Hardwood dust | Working woods such as oak, beech, walnut | FFP3 |
| Metal dust and grinding | Grinding, deburring | FFP2; FFP3 for grinding stainless steel |
| Welding fume | Electric arc welding | FFP2 or FFP3; powered air-purifying respirator for heavy fume |
| Dust containing crystalline silica | Cutting stone, concrete, ceramics | FFP3 |
There are two important limits. First, dust masks do not protect against gases and vapours: for paint, thinner, varnish and solvent vapours, a mask with a gas and vapour filter (e.g. type A) is needed. Second, a filtering mask does not increase the oxygen in the air; it is not used in tanks and similar confined spaces where there may be an oxygen deficiency.
When is a valved mask used?
The exhalation valve on a valved mask lets exhaled air out without passing through the filter. This prevents heat and moisture building up inside the mask, makes exhaling easier and keeps the mask comfortable for longer. The valve does not change the filtering of the air the user inhales; a valved and an unvalved mask of the same class protect the user to the same degree.
A valved mask is a good choice in the following situations:
- Heavy physical work, hot environments and prolonged use,
- Jobs where safety glasses fog up with an unvalved mask.
It is not suitable in the following situations:
- Places where exhaled air must be filtered, such as clean rooms, sterile production and some food work. The valve releases the user's breath unfiltered.
- Situations where a mask is worn to protect others against the risk of infectious disease.
Dust mask service life: when is it replaced?
Under Art. 6 of the Regulation on the Use of Personal Protective Equipment at Workplaces, the service life of PPE is determined taking into account the level of risk, the frequency of exposure, the characteristics of the workplace and the performance of the equipment. For a dust mask, this means:
- A mask marked NR is for a single shift; it is discarded at the end of the shift. It is not reused the next day.
- A mask marked R can be used over more than one shift if cleaned and stored according to the manufacturer's instructions.
- Whatever the type, the mask is replaced immediately when breathing becomes noticeably difficult, when the mask gets wet, dirty, crushed or misshapen, when the straps loosen and when it cannot be made to fit the face.
- A mask is not shared with anyone else; it is intended for use by one person only.
- A mask not in use is stored where it will not collect dust, in a closed box or bag; it is not left hanging around the neck or on the workbench.
Masks are provided free of charge by the employer, and employees are taught to use them hands-on (Art. 6 of the same regulation). The 2026 basic administrative fine for failing to provide employees with suitable, CE-marked PPE is 8,980 TL per employee.
Correct fitting and face fit
If even the best FFP3 mask does not fit the face, its protection factor collapses. When putting it on:
- Place the mask on the face so that it covers the chin, put the upper strap behind the head and the lower strap below the back of the neck.
- Shape the nose wire by pressing it against both sides of the nose with the fingers of both hands; do not pinch it with one finger.
- Carry out a user seal check every time you put it on: cover the mask with your palms and exhale and inhale sharply; if air leaks at the edges, readjust.
Beards, sideburns and a few days' stubble prevent the mask from fitting the face. For a bearded employee in a job requiring a dust mask, the solution is to shave the beard or to use a powered air-purifying respirator with a hood instead of a mask. If possible, have a face fit test carried out for each mask model and record which model fits each employee.
Control dust at source first
The mask is the last line of defence. Art. 5 of the PPE Regulation states that PPE is to be used only when risks cannot be prevented by collective protection, technical measures or work organisation, and that collective protection is to be given priority. The Regulation on Dust Control follows the same order: first substitution, work organisation, collective protection and engineering methods that prevent dust release; only when the measures taken are insufficient, PPE suited to the nature of the dust (Art. 5).
In the İnegöl Furniture and Woodworking Specialised OIZ in İnegöl and in the furniture workshops around it, sanding, panel sizing and CNC machining are the operations that should be addressed first as dust sources. A dust extraction system connected to the machines, filter maintenance, cleaning dust with a vacuum rather than compressed air and regular checks of the extraction system come before the mask.
For the general logic of mask selection, see our article how to select PPE, and for other risks in furniture workshops, the furniture workshop OHS checklist. You can calculate PPE fines with the OHS administrative fine tool. For assessing dust risk and choosing PPE, see our OHS specialist service, and for sector- and region-specific information, our furniture and İnegöl OSGB pages.
Frequently Asked Questions
What is the difference between FFP2 and FFP3?
Under TS EN 149, total inward leakage is at most 8% for FFP2 and at most 2% for FFP3; the particle penetration through the filter is also 6% versus 1%. A correctly fitted FFP3 lets through about four times less dust than an FFP2.
How many hours can a dust mask be used?
A mask marked NR is used for a single shift and discarded at the end of the shift. A mask marked R can be cleaned and reused according to the manufacturer's instructions. In both cases, it is replaced immediately when breathing becomes difficult, or when the mask gets wet, dirty or no longer fits the face.
Does a valved mask protect less?
No. The valve only makes it easier for exhaled air to escape; inhaled air passes through the same filter. A valved and an unvalved mask of the same class protect the user to the same degree. However, because exhaled air is not filtered, valved masks are not used in clean rooms and sterile environments.
Is a dust mask enough for paint and thinner?
No. FFP masks protect only against particles. A mask with a gas and vapour filter is needed for paint, thinner and solvent vapours; in spray painting, particle and vapour filters are used together.
A certified specialist matched to your hazard class: site inspections, approved logbook, training plan, annual plan and report follow-up.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.