EN ISO 20345:2022 is the European standard for safety footwear fitted with a protective toe cap tested to 200 J impact and 15 kN compression. Its marking combines a safety class — SB, S1, S2, S3, S4 or S5 — with add-on codes such as SR for slip resistance, FO for fuel oil resistance and P for penetration resistance. Reading that string of letters correctly is the difference between boots that pass a site audit and boots that get rejected at goods-in.
Most buyers learn the codes the hard way: an order arrives, the label says S3, and nobody checked whether “P” was actually certified or whether the slip code on the certificate still uses the older SRC system. This guide breaks the marking into its two halves, shows what each add-on code protects against, explains what changed when the 2022 edition replaced the 2011 one, and gives you a four-step check for confirming any rating a supplier claims. For the specific models we hold under each class, see our EN ISO 20345:2022 certificates listed by model.
What EN ISO 20345:2022 covers — and where its boundary sits
EN ISO 20345 applies to safety footwear: footwear incorporating a protective toe cap designed to protect the wearer’s toes against impact and compression. The headline numbers are 200 joules of impact energy and 15 kN of compressive load. If the boot has no toe cap, it is not safety footwear under this standard.
That adjacent case is covered by EN ISO 20347, the occupational footwear standard. It looks almost identical in structure — classes OB through O5, the same add-on markings — but it carries no requirement for toe protection. Roles in food processing, cleaning, healthcare and light assembly often need occupational footwear rather than safety footwear, and specifying the wrong standard either over-engineers the boot or, worse, leaves a real impact hazard unaddressed.
One more detail worth reading on a certificate: the edition. Certificates issued under the current scheme cite EN ISO 20345:2022, and newer ones increasingly cite EN ISO 20345:2022+A1:2024 as the amendment is folded in. A certificate still citing the 2011 edition is not automatically invalid — but its slip code will be an older one, and the two code systems do not read the same way.
The safety classes at a glance: SB to S5
The class letter is the core of the marking. It tells you which combination of baseline protections the certified model actually carries. S1 and S3 boots can look identical on a shelf and differ in both insert and outsole, so the class on the label is the only reliable signal.
| Class | Toe cap 200 J | Closed seat region | Antistatic | Energy absorption of seat region | Water resistance | Penetration-resistant insert | Cleated outsole |
|---|---|---|---|---|---|---|---|
| SB | Yes | No | No | No | No | No | No |
| S1 | Yes | Yes | Yes | Yes | No | No | No |
| S2 | Yes | Yes | Yes | Yes | Water absorption and penetration of the upper | No | No |
| S3 | Yes | Yes | Yes | Yes | Water absorption and penetration of the upper | Yes | Yes |
| S4 | Yes | Yes | Yes | Yes | Whole boot (polymer footwear) | No | Yes |
| S5 | Yes | Yes | Yes | Yes | Whole boot (polymer footwear) | Yes | Yes |
S4 and S5 are the classes that matter most for polymer boots — the all-PVC and all-rubber styles used in food processing, agriculture, chemical handling, fisheries and wet industrial work. With a polymer boot the entire footwear is the waterproof barrier rather than just the upper, which is why the water requirement is written against the whole boot and why the cleated outsole is mandatory from S4 upward. If you are sourcing S4 and S5 PVC rain boots for wet and chemical work, these are the two classes to ask about by name.
The add-on markings buyers miss
The class letter is the headline; the suffix codes decide whether the boot survives your actual hazards. Add the ones your risk assessment requires to the purchase specification, then ask the supplier to point to each one on the certificate.
| Marking | What it covers | When to specify it |
|---|---|---|
| P | Penetration resistance of the sole assembly (1,100 N) | Demolition, scrap handling, sites with nail or rebar risk |
| SR | Slip resistance (2022 edition marking) | Wet floors, food plants, washdown areas, oily yards |
| SRA / SRB / SRC | Slip resistance under the 2011 edition: ceramic tile with a soap solution / steel floor with glycerol / both | Only when you are reading a certificate issued under EN ISO 20345:2011 |
| FO | Resistance of the outsole to fuel oil | Workshops, fuel depots, transport maintenance, mining |
| CI | Cold insulation of the sole complex | Cold stores, freezers, winter outdoor work |
| HI | Heat insulation of the sole complex | Foundries, hot surfaces, summer outdoor work |
| HRO | Heat resistance of the outsole in contact with hot surfaces | Asphalt and roofing work, welding, smelters |
| M | Metatarsal protection | Mining, heavy fabrication, foundries |
| AN | Ankle protection | Forestry, rough terrain, emergency services |
| ESD | Electrostatic dissipative properties | Electronics assembly, explosives handling, cleanrooms |
| A | Antistatic footwear | Included in S1 and above; check it separately on SB |
| C | Conductive footwear | Specialist explosive atmospheres only |
| WR | Water resistance of the whole footwear | Extended work in standing water |
| WPA | Water penetration and absorption of the upper | Included in S2 and S3; relevant for leather uppers |
| CR | Cut resistance of the upper | Chainmail and cut-protection applications |
| SC | Scuff cap abrasion resistance | Kneeling work, where the toe cap area wears through |
| LG | Ladder grip | Work on ladders and elevated platforms |
Read that table as a checklist, not a menu. A supplier catalogue that lists every code is not evidence of anything — only the codes that appear on your model’s certificate count.
What changed when 2022 replaced 2011
The revision is more than a renumbering, and three changes are worth knowing when you read a quote or a certificate:
- Slip resistance was consolidated. The 2011 edition offered three codes — SRA, SRB and SRC — depending on which surface and lubricant were tested. The 2022 edition moves to a single SR marking. If a supplier’s current certificate still shows SRC, check the edition it was issued against: on a 2011-era certificate that is legitimate; on a 2022 certificate it should not appear.
- New optional markings were added. Codes such as SC (scuff cap abrasion) and LG (ladder grip) have come into use with the newer edition. They are optional — a boot is not deficient for lacking them — but they are useful when a specific wear pattern is costing you replacement cycles.
- The amendment is now in circulation. Certificates increasingly cite EN ISO 20345:2022+A1:2024. Our own certification for the LT-102-22 design is issued against that consolidated version, which is a practical example of how the citation appears on a real document.
For a full comparison of the two code systems, see our slip resistance ratings guide covering SRA, SRB, SRC and SR.
The underlying performance thresholds buyers care about — 200 J toe impact, 15 kN compression, 1,100 N penetration resistance — remain the anchor points. The revision mostly changed how results are labelled and which optional features can be declared.
How to verify a claimed rating in four steps
1. Read the standard citation and the edition. Confirm the certificate says EN ISO 20345 (not 20347) and note whether it cites the 2022 edition or an earlier one. This determines which slip code is meaningful.
2. Match the model number exactly. Certification is granted per model. A sibling design that shares the same outsole is not the same certified product. Our CE certificates, for example, list specific model groups — the S4 FO certificate covers LT-102, 103, 104, 107 and 118H, while the S5 FO SR certificate for LT-601 is a separate document with its own number.
3. Check the class and every add-on separately. Do not accept “S3” as shorthand for “S3 plus everything you need”. If your risk assessment calls for penetration resistance and slip resistance, look for P and SR on the same certificate that carries the class.
4. Confirm validity and scope today. Check that the current date sits inside the certificate’s validity period and that the scope covers the colour, height and size range you are ordering. Variants are sometimes listed separately.
The full list of models, classes, certificate numbers and validity dates is on our certifications page. If you need the underlying test reports or the EU declaration of conformity for a specific model, request the certificate pack and we will send it with the model schedule attached.
Matching the code to the workplace
| Environment | Hazards driving the choice | Class to specify | Add-on markings to add |
|---|---|---|---|
| Construction and civil engineering | Falling objects, nails, uneven ground, standing water | S3 | P, SR |
| Food and beverage processing | Wet floors, washdown chemicals, hygiene, long shifts | S4 or S5 polymer boot | SR, FO |
| Agriculture and farming | Water, slurry, manure acids, long wear hours | S4 or S5 polymer boot | SR, FO |
| Chemical handling and cleaning | Splash exposure, degreasers, acids and alkalis | S5 polymer boot | SR, FO |
| Cold storage and logistics | Sub-zero surfaces, forklift traffic, condensation | S3 | CI, SR |
| Oil, gas and fuel handling | Hydrocarbons, static, hot surfaces | S3 or S5 | FO, HRO, ESD where certified |
| Mining and resources | Impact, crush, puncture, heat, fuel oil | S3 or S5 | P, FO, HRO, M where certified |
Use this as a starting brief, then validate it against your own risk assessment. Under EU rules, PPE sits at the end of the hierarchy of controls — the boot is the last line of defence, not a substitute for controlling the hazard. You can also browse the wider safety shoes and boots range to see which lines fit your programme. If you are specifying boots for a European site alongside an Australian one, our comparison of AS 2210.3 and EN ISO 20345 shows where the two systems diverge. For site-specific selection on construction work, see the construction safety shoes buying guide.
Frequently asked questions
What does S3 mean on a safety boot?
S3 means the footwear has a 200 J protective toe cap, a closed seat region, antistatic properties, energy absorption in the seat region, resistance to water penetration and absorption of the upper, a penetration-resistant insert and a cleated outsole. It does not automatically include slip resistance or fuel oil resistance — those are separate markings (SR and FO) that must appear on the certificate as well.
What is the difference between S3 and S5?
Both include the toe cap, antistatic properties, energy absorption and a penetration-resistant insert. The difference is the water requirement: S3 is tested on the upper, while S4 and S5 apply to all-polymer or all-rubber footwear where the whole boot is water-resistant. S5 is therefore the class used for waterproof polymer safety boots, with S4 the equivalent without the penetration-resistant insert.
Is SRC the same as SR?
Not exactly, and the distinction matters when you read a certificate. SRC comes from EN ISO 20345:2011 and means the footwear passed both slip tests available at the time — SRA on ceramic tile with a soap solution and SRB on a steel floor with glycerol. The 2022 edition replaced those three codes with a single SR marking. If you are buying against the current edition, ask for SR; if a certificate shows SRC, check which edition it was issued under.
Does a 200 J toe cap rating mean the boot is fully certified?
No. The toe cap is only one requirement. Full certification to a class such as S5 includes antistatic performance, energy absorption, water resistance of the whole boot, penetration resistance and a cleated outsole, plus every add-on marking the supplier claims. The certificate, not the catalogue, is where you confirm the complete package.
How long is an EN ISO 20345 certificate valid?
Product certification under the EU PPE Regulation typically runs for five years, subject to ongoing surveillance by the notified body, but validity periods vary and each certificate lists its own dates. Always check the validity window on the document you are given rather than assuming a standard term.
Further reading
- ISO 20345 – the international standard for safety footwear
- European Commission – PPE Regulation (EU) 2016/425 – the conformity route behind CE marking
- ISO 20347 – occupational footwear without a protective toe cap
