Guides

Respiratory protection: standards, rules and terms explained

Standards, regulations and technical terms around respiratory protection on one page: what each standard regulates, what codes such as NR, D or A1B1E1K1 stand for and where to find more. Every entry points to the matching guide or source.

As of 6 October 2026, DS SafetyWear Arbeitsschutzprodukte GmbH

Product standards for masks and filters

The test values are in the text of the standard. The instructions for use of the individual item name the version applied.
StandardSubjectMore
EN 149Filtering half masks against particles (FFP1, FFP2, FFP3, marking NR, R, D)EN 149 explained
EN 140Half masks and quarter masks as face piece for filters, for example the half mask AG360Half mask AG360
EN 136Full face masks as face piece for filters, for example the full-face mask AG700Full-face mask AG700
EN 143Particle filters for respiratory protective devices, for example P3Particle filters P3
EN 14387Gas filters and combined filters (types A, B, E, K and classes)Filter classes and colour codes
EN ISO 9001Quality management systems: requirements (certification of the company, not a product test)ISO 9001 explained

Regulations and rule sets

Rule setWhat it is aboutMore
Regulation (EU) 2016/425The PPE Regulation: requirements for manufacturers, categories, conformity assessment, CE markingEU type-examination explained
DGUV Rule 112-190Use of respiratory protective devices: protection level (multiple of the limit value), fit, wearing time, instructionRespiratory protection duties
German Hazardous Substances Ordinance (GefStoffV)Order of protective measures: technical and organisational measures before personal protective equipmentRespiratory protection duties
TRGS 900Workplace exposure limitsWorkplace exposure limit AGW
TRGS 528Welding workRespiratory protection for welding
TRGS 553Wood dustRespiratory protection for wood dust
TRGS 559Quartz-containing dust (assessment benchmark 0.05 mg/m³)Respiratory protection for quartz dust
TRBA/TRGS 406Respiratory sensitisers, for example flour dustFlour and feed dust
ArbMedVV, AMR 14.2, G 26Occupational health care, classification of respiratory protective devices in groupsG 26 and health care
PPE Use Ordinance (PSA-BV)Employer duties for selecting, providing and using PPERespiratory protection duties

Technical terms from A to Z

The entries on filters and limit values replace neither the safety data sheet nor the instructions for use nor the risk assessment.
TermMeaningMore
A1, A2 (type A)Gas filter against organic gases and vapours with boiling point above 65 °C, colour brown. The digit gives the class.Respiratory protection for solvents
Type B, E, KB: inorganic gases (grey), E: acid gases (yellow), K: ammonia and amines (green)Chlorine and acids, Ammonia
P3Particle filter with the highest retention level, colour whiteFilter classes and colour codes
Gas filter class 1Gas filter with small capacity, according to the AirGuard Pro instructions for use up to 0.1 vol.% (1,000 ml/m³). Higher classes: see the instructions for use of the filter.Filter classes and colour codes
AGW (workplace exposure limit)Concentration of a substance in the air that according to current knowledge generally does not harm with daily exposure. It is listed in TRGS 900.Workplace exposure limit AGW
Protection level, multiple of the limit valueHow many times the limit value a device is permitted for at most: FFP1 4, FFP2 10, FFP3 and half mask 30, full-face mask 400 (DGUV Rule 112-190)FFP1, FFP2, FFP3
NR, R, DNR not reusable, R reusable, D dolomite clogging test passedEN 149 explained
Category IIIHighest PPE category for risks of irreversible harm or death, for example respiratory protection against hazardous substances. Requires a notified body.EU type-examination explained
Notified bodyTesting and certification body listed by the European Commission with a four-digit identification number, for AirGuard Pro CCQS (2834). The list is in NANDO.Certificate after a change of address
Module B, C2, DConformity assessment procedures: B is the EU type examination, C2 and D add monitoring of production (category III)EU type-examination explained
EU declaration of conformityDeclaration of the manufacturer that the PPE meets the requirements of the regulation. It has to be kept up to date.Data sheets
Face seal, fit testTight fit of the face piece on the face. The fit test checks qualitatively (smell, taste) or quantitatively (instrument).Face fit testing
Wearing time, duration of useTime a device is used continuously, followed by recovery. Guide values are given in DGUV Rule 112-190.Wearing time and recovery
Bayonet, RD40Two filter connections: bayonet on the half mask AG360, round thread RD40 on the full-face mask AG700Bayonet or RD40

If you know which substance you need protection from, the respirator finder leads to the matching combination. All documents for the items are under Data sheets.

Frequently asked questions

What is the difference between EN 149 and EN 143?

EN 149 covers filtering half masks (FFP masks) in which the filter material forms the mask. EN 143 covers particle filters connected to a face piece such as a half or full-face mask.

What does EN 14387 stand for?

Gas filters and combined filters. It defines types (A, B, E, K) and classes, for example A1B1E1K1.

What does category III mean for PPE?

It is the highest PPE category under Regulation (EU) 2016/425. Respiratory protection against hazardous substances belongs to it. A notified body examines the design and production is monitored.

What is an AGW?

The workplace exposure limit, the concentration of a substance in the air that according to current knowledge generally does not harm with daily exposure. It is listed in TRGS 900.

Where do I find the full text of a standard?

Standards are paid for, for example at Beuth Verlag. Rule sets such as DGUV Rules and TRGS are free from DGUV and BAuA.

Sources

For purchasing and occupational safety

Not sure what suits your workplace?

Send us the activity and the substances per safety data sheet. We advise on selection and send samples for a wearing trial.

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