Assigned Protection Factors By Country
How do assigned protection factors differ by country?
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Short answer: assigned protection factors (APFs) answer the same question everywhere — how many times cleaner is the air inside the facepiece than outside? — but the credited numbers differ by jurisdiction. OSHA's Table 1 rates every half-face device at 10 and a full facepiece at 50; the UK runs a five-rung ladder of 4, 10, 20, and 40 (plus 2000) that credits an FFP3 with twice the American half-face number; European selection starts from EN 529's laboratory-derived nominal protection factors with each member state assigning its own workplace APFs; and Australia's AS/NZS 1715 adds the rule that P3-level protection exists only on a full facepiece. Same physics, four rulebooks.
This guide is the cross-border companion to our US-focused Assigned Protection Factors Explained — read that one for the OSHA arithmetic (APF × exposure limit = maximum use concentration), and this one when a spec sheet, tender, or multinational program crosses a border. It is part of the international respirator standards pillar.
Why this matters.
The protection factor is the number that turns a measured exposure into a legal selection decision, and it does not travel. A half mask with 99.95%-class filters is credited 10× protection in Denver, 20× in London, and 30× under German DGUV rules — while the identical filter-and-facepiece combination in Sydney is credited only P2-level protection because AS/NZS 1715 reserves the top class for full facepieces. Copy a maximum use concentration across a border and the calculation is wrong before the worker ever dons the mask.
The APF concept in one paragraph
An APF is the minimum level of protection a properly functioning, correctly fitted respirator class is expected to deliver inside a complete program. APF 10 means the wearer breathes air at least ten times cleaner than ambient; multiply the APF by the occupational exposure limit and you get the maximum concentration in which that class may be used. The inputs on both sides of that multiplication are national: the APF comes from the jurisdiction's table, and the exposure limit from its list — OSHA PELs, UK WELs, or the ACGIH TLVs many programs adopt voluntarily, a distinction unpacked in the TLV-vs-PEL guide.
APF vs NPF: assigned versus nominal
Europe's system introduces a second number that trips up readers of EU spec sheets. The nominal protection factor (NPF) is laboratory arithmetic: 100 divided by the device class's maximum permitted total inward leakage under EN 149 or the facepiece standard. An FFP2's 8% leakage ceiling yields an NPF of 12.5; an FFP3's 2% yields 50. The NPF is a certification artifact, not a workplace promise — EN 529 and national authorities then assign workplace APFs at or below it, reflecting field reality the same way OSHA's 2006 APF table did for the US. The UK's HSG53 ladder (4, 10, 20, 40, 2000) is one national implementation; German DGUV rules credit an FFP3 at 30. When a European datasheet says "protection factor 50" for an FFP3, check which number it is quoting — nominal, almost certainly.
The master table: four systems, one device list
Values below are the workhorse air-purifying classes; atmosphere-supplying equipment extends every ladder upward. UK values follow HSG53; US values OSHA 29 CFR 1910.134 Table 1; Australian treatment follows AS/NZS 1715; European NPFs follow the EN-class leakage arithmetic with national APFs assigned beneath them.
| Device | US (OSHA APF) | UK (HSE APF) | EU (EN 529 NPF, lab) | Australia/NZ (AS/NZS 1715) |
|---|---|---|---|---|
| Disposable, 80% class (FFP1/P1) | — (no US class) | 4 | ≈4 | Protection factor 10 tier not credited — nuisance-dust use |
| Disposable, 94–95% class (N95 / FFP2 / P2) | 10 | 10 | 12.5 | 10 |
| Disposable / half mask, 99–99.95% class (FFP3 / P3 filter on half mask) | 10 (P100 half mask) | 20 | 50 (nominal; national APFs lower, e.g. 30 in Germany) | Credited as P2-level (10) — P3 requires full facepiece |
| Full facepiece, HEPA-class filters (P100 / P3) | 50 | 40 | Up to ~1000 nominal; national APFs far lower | P3 level credited; 1715 tables govern the figure |
| Loose-fitting PAPR hood/helmet | 25 (1000 with manufacturer evidence) | 20 (TH2) / 40 (TH3) | Class-dependent (TH1–TH3) | 1715 tables by PAPR class |
Three rows deserve a second look. The 94–95% disposable row is the world's most harmonized number — effectively 10 everywhere, which is why N95/FFP2/P2 programs translate so cleanly. The 99%-class row is the opposite: 10, 20, 30, or "P2-level" depending on the flag, the single biggest cross-border discrepancy in respiratory protection. And the full-facepiece row shows the US as the outlier on the generous side at 50 against the UK's 40. Device-level context for these rows lives in the N95 vs P100 guide, the PAPR guide, and the EN 149 guide.
Safety note: every ladder in this table stops at the same wall — no APF, in any jurisdiction, authorizes an air-purifying respirator in oxygen-deficient atmospheres or IDLH conditions, which are reserved for supplied-air and SCBA equipment selected by a qualified professional.
The three cross-border traps
Trap 1: same device, different credit
A half mask wearing HEPA-class filters — the classic 3M 6000 series with 2097 P100s build — is credited 10 in the US, and its FFP3/P3-class counterparts 20 in the UK and 30 under German rules. The hardware's capability didn't change; the regulatory philosophy did.
Trap 2: Australia's full-facepiece gate
Under AS/NZS 1715, that same half-mask configuration is credited only P2-level protection — the P3 class opens exclusively with a full facepiece, as our AS/NZS 1716 guide details. Translating "half mask + P100, APF 10" from a US program into "P3 protection" in an Australian tender is the classic error in both directions.
Trap 3: maximum use concentrations don't travel
MUC = APF × exposure limit, and both factors are national. Respirable-silica limits, lead limits, and solvent limits differ across OSHA PELs, UK WELs, and other national lists — so even where the APF matches, the MUC usually doesn't. Recompute per jurisdiction, per the worked method in APF Explained, with the silica case study in the OSHA silica guide.
Worked example: one exposure, four selections
A grinding task measures respirable dust at 12 times the applicable exposure limit. Selecting per jurisdiction:
- United States: APF 10 (N95 or half mask) fails at 12×; step up to a full facepiece (APF 50) — the route our full-face roundup and the full-face collection serve.
- United Kingdom: APF 10 fails; an FFP3 or half mask with P3 (APF 20) clears 12× — the UK reaches compliance one rung earlier, per the ladder in our UK RPE guide.
- Germany (EU): FFP3 at APF 30 clears it with margin; verify the member state's assigned table rather than the EN 529 nominal figure.
- Australia: half-mask configurations cap at 10 regardless of filter, so 12× forces a full facepiece with P3 or a powered system under the 1715 tables.
Four compliant answers, three different hardware tiers — from one measurement. That's the whole reason this page exists.
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Frequently asked questions
How do assigned protection factors differ by country?
assigned protection factors (APFs) answer the same question everywhere — how many times cleaner is the air inside the facepiece than outside? — but the credited numbers differ by jurisdiction.
What is the APF concept in one paragraph?
An APF is the minimum level of protection a properly functioning, correctly fitted respirator class is expected to deliver inside a complete program. APF 10 means the wearer breathes air at least ten times cleaner than ambient; multiply the APF by the occupational exposure limit and you get the maximum concentration in which that class may be used.
What is the difference between APF and NPF?
Europe's system introduces a second number that trips up readers of EU spec sheets. The nominal protection factor (NPF) is laboratory arithmetic: 100 divided by the device class's maximum permitted total inward leakage under EN 149 or the facepiece standard.
What is the master table?
Values below are the workhorse air-purifying classes; atmosphere-supplying equipment extends every ladder upward. UK values follow HSG53; US values OSHA 29 CFR 1910.134 Table 1; Australian treatment follows AS/NZS 1715; European NPFs follow the EN-class leakage arithmetic with national APFs assigned beneath them.
What is trap 1?
A half mask wearing HEPA-class filters — the classic 3M 6000 series with 2097 P100s build — is credited 10 in the US, and its FFP3/P3-class counterparts 20 in the UK and 30 under German rules. The hardware's capability didn't change; the regulatory philosophy did.
What is trap 2?
Under AS/NZS 1715, that same half-mask configuration is credited only P2-level protection — the P3 class opens exclusively with a full facepiece, as our AS/NZS 1716 guide details. Translating "half mask + P100, APF 10" from a US program into "P3 protection" in an Australian tender is the classic error in both directions.
What is trap 3?
MUC = APF × exposure limit, and both factors are national. Respirable-silica limits, lead limits, and solvent limits differ across OSHA PELs, UK WELs, and other national lists — so even where the APF matches, the MUC usually doesn't.
What is worked example?
Four compliant answers, three different hardware tiers — from one measurement. That's the whole reason this page exists.
Further reading on this site
- Assigned Protection Factors (APF) Explained — the US arithmetic this page internationalizes.
- International respirator standards: the complete guide — the pillar with all six certification systems.
- UK RPE and face fit testing — the 4/10/20/40/2000 ladder in its enforcement context.
- AS/NZS 1716 explained — the P3 full-facepiece gate in full.
- EN 149 and EN 143 explained — the classes behind the European NPF math.
- ACGIH TLVs vs OSHA PELs — choosing the exposure-limit input.
- Full face mask respirators — the hardware tier the higher rungs demand.
Why trust this guide? WC Safety is an independent industrial PPE review and research site. This guide was authored by our editorial desk with no manufacturer input and no paid placement. Every protection-factor claim is cross-referenced against the assigning authority's published table — OSHA 29 CFR 1910.134 Table 1, HSE HSG53 and the RPE selection sheets, EN 529's nominal-factor framework, and AS/NZS 1715 — and the German DGUV figure against its published rules. WC Safety earns Amazon affiliate commissions on outbound clicks; that relationship does not influence this guide.
Authored by Steven Eaton, WC Safety Editorial — independent, specification-based product research · international respiratory protection desk.
Last reviewed: · Reviewed by: Steven Eaton, WC Safety Editorial · Sources reviewed: OSHA 29 CFR 1910.134 Table 1 and the OSHA APF guidance document, HSE HSG53 and RPE selection sheets, EN 529, AS/NZS 1715:2009, DGUV respiratory protection rules.
Editorial standard: Zero sponsored listings. No manufacturer input. Every protection-factor figure verified against the assigning authority's published table.
Last reviewed: · Reviewed by: Steven Eaton, WC Safety Editorial · Sources reviewed: OSHA 29 CFR 1910.134 Table 1 and the OSHA APF guidance document, HSE HSG53 and RPE selection sheets, EN 529, AS/NZS 1715:2009, DGUV respiratory protection rules.
Editorial standard: Zero sponsored listings. No manufacturer input. Every protection-factor figure verified against the assigning authority's published table.
How this guide was researched
Primary sources: OSHA 29 CFR 1910.134 (Table 1) · OSHA 3352 — Assigned Protection Factors · HSE HSG53 · HSE RPE selection sheets (APF 20 series) · SafeWork SA — selecting appropriate RPE. Reviewed quarterly and on any change to the cited tables or guidance.
Primary sources: OSHA 29 CFR 1910.134 (Table 1) · OSHA 3352 — Assigned Protection Factors · HSE HSG53 · HSE RPE selection sheets (APF 20 series) · SafeWork SA — selecting appropriate RPE. Reviewed quarterly and on any change to the cited tables or guidance.
Disclosure
WC Safety is an independent industrial PPE review and research site and a participant in the Amazon Associates Program; we earn from qualifying purchases made through tagged links and sell nothing directly. No sponsorships, no paid placements. General information, not medical, legal, or regulatory advice — consult a Certified Industrial Hygienist or qualified safety professional for commercial respiratory protection programs.
WC Safety is an independent industrial PPE review and research site and a participant in the Amazon Associates Program; we earn from qualifying purchases made through tagged links and sell nothing directly. No sponsorships, no paid placements. General information, not medical, legal, or regulatory advice — consult a Certified Industrial Hygienist or qualified safety professional for commercial respiratory protection programs.
Related reference
Neighbouring references on this site: assigned protection factors explained, written respiratory protection program requirements, how to choose a respirator cartridge: complete selection guide, best respirator mask for asbestos — 10 niosh-approved masks ranked by, moldex 9000 vs 3m full-face respirator — 2026 apf 50 platform comparison, and when do you need a respirator? 7 signs you need one — hazards, tasks &.
Why trust WC Safety
WC Safety is an independent, affiliate-supported review site. It is not a retailer: it holds no inventory, takes no orders, and earns only from qualifying purchases through clearly marked links — which never changes what a product is rated to do. Standards language is taken from the regulation text directly, and ratings are reported as the manufacturer publishes them. We run no laboratory and perform no testing of our own. Where published sources disagree, we say so and plan on the conservative figure rather than the flattering one.
Our methodology
Figures come from the regulation and the published specification, in that order. Derated numbers are calculated, not estimated. Nothing here is presented as a measured result, because we measure nothing.
Researched and written by Steven Eaton, editor of WC Safety. Steven holds no safety certification and does not test products; this page compares what manufacturers and regulators publish, with the gaps in that record marked. Last reviewed August 2026.
Frequently Asked Questions
How do assigned protection factors differ by country?
assigned protection factors (APFs) answer the same question everywhere — how many times cleaner is the air inside the facepiece than outside? — but the credited numbers differ by jurisdiction.
What is the APF concept in one paragraph?
An APF is the minimum level of protection a properly functioning, correctly fitted respirator class is expected to deliver inside a complete program. APF 10 means the wearer breathes air at least ten times cleaner than ambient; multiply the APF by the occupational exposure limit and you get the maximum concentration in which that class may be used.
What is the difference between APF and NPF?
Europe's system introduces a second number that trips up readers of EU spec sheets. The nominal protection factor (NPF) is laboratory arithmetic: 100 divided by the device class's maximum permitted total inward leakage under EN 149 or the facepiece standard.
What is the master table?
Values below are the workhorse air-purifying classes; atmosphere-supplying equipment extends every ladder upward. UK values follow HSG53; US values OSHA 29 CFR 1910.134 Table 1; Australian treatment follows AS/NZS 1715; European NPFs follow the EN-class leakage arithmetic with national APFs assigned beneath them.
What is trap 1?
A half mask wearing HEPA-class filters — the classic 3M 6000 series with 2097 P100s build — is credited 10 in the US, and its FFP3/P3-class counterparts 20 in the UK and 30 under German rules. The hardware's capability didn't change; the regulatory philosophy did.
What is trap 2?
Under AS/NZS 1715, that same half-mask configuration is credited only P2-level protection — the P3 class opens exclusively with a full facepiece, as our AS/NZS 1716 guide details. Translating "half mask + P100, APF 10" from a US program into "P3 protection" in an Australian tender is the classic error in both directions.
What is trap 3?
MUC = APF × exposure limit, and both factors are national. Respirable-silica limits, lead limits, and solvent limits differ across OSHA PELs, UK WELs, and other national lists — so even where the APF matches, the MUC usually doesn't.
What is worked example?
Four compliant answers, three different hardware tiers — from one measurement. That's the whole reason this page exists.
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