EN ISO 20345 Explained: Safety Classes and 2022 Updates

EN ISO 20345 Explained: Safety Classes and 2022 Updates

EN ISO 20345 is not a single test or a simple badge. It's a structured system of mandatory requirements, class markings, and test methods that build on each other in ways that matter enormously in practice. A failed shipment, a product recall, or a worker injured because the boots on site didn't actually meet the standard printed on the box — these are real consequences of misunderstanding the standard, and they can arise whenever documentation doesn't match actual product performance.

For UK distributors sourcing safety footwear from China, the compliance challenge is sharpened by one uncomfortable reality: documentation quality varies sharply between suppliers. Many factories can print the right markings on a boot. Far fewer can back them up with current Notified Body certificates, model-specific lab reports, and consistent production-level quality control. That gap is where liability exposure lives, and it sits entirely with the importer under UK PPE regulations. It's also why UK distributors increasingly prioritise manufacturers who treat certified product and clean documentation as part of the standard offering, not something to chase down separately.

This article breaks down what the standard requires, what each class marking actually means, what the 2022 revision changed, and how to verify compliance before you commit to a production run.

What EN ISO 20345 Actually Requires from Every Safety Boot

The mandatory baseline that applies to all safety classes

Before any class marking, from SB to S7, a safety boot must clear a set of mandatory baseline requirements. These cover non-toxic materials, ergonomic fit, defined upper and sole resistance properties, and labelling obligations. Under the 2022 revision, hydrocarbon (FO) resistance is now a mandatory baseline requirement for most classes, replacing its previous status as an optional performance marking. Passing this baseline is not optional. Even the most basic SB-marked boot must clear every foundational test before any class designation applies.

The 200J toe cap test: how it works and what it proves

The toe cap impact test drops a 20 kg weight from approximately one metre, delivering 200 joules of impact energy to the toe area. The boot must simultaneously withstand 15 kilonewtons of compression force without collapsing. Steel toe caps remain the traditional solution, but composite alternatives are fully permitted under the standard provided they demonstrate equivalent performance. What the test proves is not simply that the boot contains a toe cap — it proves the cap performs under the precise, standardised force conditions that define the protection claim.

Slip resistance, energy absorption and other baseline tests

Beyond toe protection, the baseline covers heel energy absorption, midsole abrasion resistance, and resistance to electrical hazards. Slip resistance is measured using a pendulum tester on a ceramic tile with a soap solution, simulating the heel strike and forepart push-off motion. Under the 2022 revision, this test shifted from optional marking territory into the mandatory baseline — a significant change covered in depth later in this article. The combination of tests at the baseline level ensures that even the most entry-level certified boot provides meaningful, verified protection across the conditions where failure is most costly.

Safety Class Markings Decoded: SB Through S7

SB and S1: the entry point for safety footwear

SB is the most minimal class: a protective toe cap and nothing else. There's no closed heel, no antistatic property, no energy absorption requirement, and no midsole. It's found primarily on safety clogs and open-backed footwear used in specific, controlled environments. S1 builds substantially on SB, adding a closed heel, antistatic properties, heel energy absorption, and hydrocarbon resistance. S1 is well suited to dry indoor environments where sharp objects underfoot are not a realistic hazard.

S1P, S2 and S3: where puncture and water resistance enter

S1P adds a puncture-resistant midsole to the S1 feature set while remaining unwaterproofed, making it the right choice for dry environments with sharp object hazards. S2 takes the full S1 specification and adds water penetration and absorption resistance, covering wet environments where a midsole isn't required. S3 combines everything: S2 protections plus a puncture-resistant midsole and a profiled, oil and acid-resistant outsole, designed for wet and contaminated environments where both water and underfoot hazards are present.

S4, S5, S6 and S7: the waterproof and extended classes

S4 and S5 are the fully waterproof equivalents of S1 and S3, constructed as polymer or rubber boots rather than leather or textile uppers. S6 and S7 were introduced in the 2022 revision, providing waterproof upper (WR certified) variants of the S1 through S3 range. These classes sit between the traditional upper-based classes and the fully moulded S4/S5 construction. They appear less frequently in standard UK procurement but are growing in relevance for construction, agriculture, and drainage environments where waterproofing is essential but a rubber boot isn't practical.

The Test Methods and Pass Criteria Behind the Markings

How slip resistance is tested: SRA, SRB and SRC under the 2011 standard

Under EN ISO 20345:2011, slip resistance was marked as SRA, SRB, or SRC, each corresponding to a specific test surface and contaminant combination. SRA used a ceramic tile with sodium lauryl sulphate soap solution. SRB used a steel plate with glycerol. SRC required passing both. Pass thresholds required a slip resistance ratio of 0.32 or above at the heel and 0.28 or above at the forepart. These markings still appear on products certified before the 2022 transition deadline, so buyers encountering existing stock need to understand what each one confirms and, critically, what it doesn't cover.

Puncture resistance: what the P marking requires

The penetration resistance test, conducted in accordance with EN ISO 20344 (the test method standard for safety footwear), drives a 4.5 mm diameter nail into the midsole at 1,100 newtons of force. The midsole must not be fully penetrated, with a maximum allowable penetration depth of 2 mm. Under the 2011 standard, this test applied specifically to metallic midsoles and was limited to the S1P, S3, and S5 classes. The 2022 revision introduced non-metallic alternatives at different force thresholds, creating new classification subtypes with direct implications for puncture-resistant footwear specification and boot weight.

What Changed in EN ISO 20345:2022

Slip resistance is now a mandatory baseline, not an optional marking

This is the most consequential change in the 2022 revision for anyone specifying or sourcing safety footwear. Passing the slip resistance test on ceramic tile with soap solution is now a basic requirement for all safety classes, embedded in the baseline rather than treated as an optional performance marking. The three-part SRA/SRB/SRC system no longer applies to products certified under the new standard. An optional enhanced SR marking is available for products that also pass a ceramic tile with glycerol test, but the baseline slip requirement is non-negotiable. A boot without demonstrable slip resistance does not qualify under the 2022 standard.

New classification subtypes: S3L, S3S and S7S

The 2022 revision introduced non-metallic midsole variants that give specifiers greater precision when matching footwear to specific hazard profiles. S3L (Type PL) uses a non-metallic midsole tested at 330 newtons, providing lower-level puncture protection where the hazard profile doesn't require full resistance. S3S (Type PS) delivers non-metallic midsole performance at 1,100 newtons, matching the original P standard without using metal. S7S combines Type PS midsole protection with full waterproofing, covering the most demanding wet environments. These subtypes allow lighter, more flexible boots in applications where a traditional steel midsole adds unnecessary weight or reduces wearer comfort over long shifts.

Transition timeline and what still counts as compliant

Notified Bodies could no longer issue new certifications under EN ISO 20345:2011 after 11 November 2024. Products already certified under the 2011 standard remain valid through their individual certificate expiry dates, which can extend to approximately November 2029 — buyers should verify exact expiry dates directly with the issuing Notified Body or accredited approval body. Buyers placing orders now that will be sold over the next several years need to know which version of the standard a product is certified under and what that version actually required the product to prove. The version of the certificate determines the scope of compliance, and those two versions are not equivalent in every respect.

How to Verify Compliance Before You Buy or Import

What to look for on the boot itself

Every EN ISO 20345-compliant boot must carry mandatory markings: manufacturer identification, size, the standard designation, safety class marking, and performance pictograms for specific features. The CE mark or UKCA mark must be present and visible. CE remains valid for EU market distribution and for products sold in Northern Ireland under the Windsor Framework. UKCA is the required conformity route for Great Britain. If you're selling into the GB market, confirm whether your supplier's certification supports UKCA, CE, or both — they are not interchangeable for this purpose.

Documents to request from your supplier

Three documents form the core compliance stack for Category II PPE under Regulation (EU) 2016/425 and its UK equivalent:

• EU-Type Examination Certificate — issued by a recognised Notified Body (or UK-equivalent certificate from an Approved Body for UKCA), confirming that a representative sample of the model was independently tested.
• Third-party lab test reports — from an accredited testing facility, detailing the specific tests conducted and the results achieved.
• Declaration of Conformity — signed by the manufacturer.

One distinction matters here: lab reports confirm that a tested sample met the standard — they do not guarantee that every pair produced to that design will perform identically in production. That gap is where production-level quality control becomes critical.

Why production-level QC matters beyond certification

Certification establishes that a design passed a test. It does not guarantee consistent factory output across a bulk production run. The questions worth asking any supplier include: Are toe cap insertions verified during production? Are sole adhesion tests conducted on bulk batches? Does the factory hold ISO 9001 certification, and what does the internal QC process actually cover? Certification is the entry requirement. Consistent production discipline is what makes that certification meaningful when the boots are on a worker's feet.

What UK Buyers Must Check When Sourcing from China

The compliance documentation gap and how it shows up

UK buyers importing safety footwear from China regularly encounter a specific problem: many factories can produce boots labelled with EN ISO 20345 markings but cannot produce a current, model-specific Notified Body certificate or a credible third-party lab report tied to the exact model being ordered. Under UK PPE regulations, the compliance burden rests with the importer, not the overseas manufacturer. That means the UK distributor carries the liability if a product doesn't meet the standard it claims. For distributors supplying trade buyers who resell into workplaces, that exposure is direct and serious.

How a certified manufacturing partner changes the equation

Working with a manufacturer that holds ISO 9001 certification, BSCI compliance, and a documented track record of supplying EN ISO 20345-compliant safety footwear to UK distributors is not a minor operational preference. It fundamentally shifts where compliance risk concentrates. Shoe-Tec's manufacturing operations span Zhejiang, Guangdong, and Fujian, with independent quality control built into every production stage and a working knowledge of EU and UK safety standards developed through years of supplying compliant product to international buyers. UK distributors who need clean documentation, certified product, and consistent bulk quality benefit from working with a single, accountable manufacturing partner who understands what that actually requires, rather than assembling those assurances across multiple unverified suppliers.

Building Your Sourcing Approach on Solid Ground

EN ISO 20345 is a rigorous, layered system. Each class marking carries a specific set of mandatory tests. The 2022 revision tightened requirements, expanded classification options, and made slip resistance a baseline rather than an optional feature. Understanding what the standard requires at each level, how the tests work, and what the 2022 changes mean in practice gives UK buyers the foundation they need to specify, audit, and source safety footwear with confidence.

The compliance burden is real. It's also manageable when the manufacturing side is handled by a partner with the right certifications, production discipline, and genuine familiarity with what UK distributors need. That's what Shoe-Tec is built to deliver. Contact the team to discuss your compliance requirements and request documentation for any model in the range.