Buying guide
S1 vs S1P vs S3 vs S7: which rating do you need?
What is the difference between S1, S1P, S3 and S7 safety boots?
The short answer
For most UK work the answer is S1P or S3. Buy S1P if you work indoors on dry floors and need protection from nails or sharp objects underfoot. Buy S3 if you work outdoors or anywhere wet, because S3 adds a water-resistant upper and a cleated sole on top of everything S1P gives you. S7 is the newest class and is S3 plus whole-boot water resistance, for standing on wet ground all day. Plain S1 is only worth buying if nothing sharp is ever underfoot, because it has no midsole protection at all. Every one of these classes includes the same 200 joule toecap, so none of them is safer at the toe than any other.
What the letters actually mean
Every safety boot sold in the UK is certified to EN ISO 20345, the European and British standard for safety footwear. The S code tells you which bundle of protections the boot was tested against. The classes stack: each one includes everything below it and adds something. That is the whole system, and once you see it as a stack rather than a list of unrelated codes it stops being confusing.
The one thing every class shares
SB, S1, S1P, S2, S3, S5, S6 and S7 all carry a toecap tested to 200 joules of impact and 15 kN of compression. An S1 trainer protects your toes exactly as well as an S7 boot. The classes differ in what they protect underfoot and against water, not at the toe.
The comparison table
| Class | 200J toecap | Antistatic + closed heel | Water-resistant upper | Midsole protection | Cleated outsole | Whole-boot water resistant |
|---|---|---|---|---|---|---|
| SB | Yes | No | No | No | No | No |
| S1 | Yes | Yes | No | No | No | No |
| S1P | Yes | Yes | No | Yes | No | No |
| S2 | Yes | Yes | Yes | No | No | No |
| S3 | Yes | Yes | Yes | Yes | Yes | No |
| S4 | Yes | Yes | Moulded, fully waterproof | No | No | By construction |
| S5 | Yes | Yes | Moulded, fully waterproof | Yes | Yes | By construction |
| S6 | Yes | Yes | Yes | No | No | Yes |
| S7 | Yes | Yes | Yes | Yes | Yes | Yes |
S4 and S5 are the odd pair in that table. They are not leather boots with features added, they are moulded rubber or polymer wellingtons, waterproof because of how they are made rather than because a membrane was added. S5 is the wellington specification you want on a farm or in a wash-down area: waterproof, with midsole protection and a cleated sole.
So which one should you buy?
Construction, groundworks, civils
Nails underfoot and wet ground are both routine. S3 is the de facto site specification across the UK, and most site inductions ask for it by name.
Warehouse, logistics, distribution
Dry indoor floors mean the water-resistant upper is wasted money, but pallet nails and strapping are a real risk. S1P is lighter and cooler than S3 for the same underfoot protection.
Standing on wet ground all day
S7 is S3 with the whole boot tested for water resistance rather than just the upper. If your feet get wet in S3 boots by lunchtime, this is the class that fixes it.
Farms, food production, wash-down areas
A moulded wellington is waterproof by construction, takes a hosing down, and S5 adds the midsole protection that a plain S4 leaves out.
Light indoor work, driving, facilities
Only where nothing sharp is ever underfoot. You gain a lighter, cooler shoe. You give up the midsole, so if there is any doubt at all, pay the small difference for S1P.
Engineering, workshops, light industrial
S1P indoors, S3 if the job takes you outside or across a yard. Add HRO if there is hot swarf or contact with hot surfaces.
The suffix that trips people up: P, PL and PS
Midsole protection stops something sharp on the floor going up through the sole and into your foot. The 2022 version of the standard splits it into three, and the letters tell you what the insert is made of and how hard it was tested.
A steel plate. Long track record, the least costly to manufacture, and it covers slightly less of the sole area than a textile insert because it cannot flex around the shape of the foot.
A textile or composite insert tested against a 4.5mm nail. Lighter and more flexible than steel, covers the full width of the sole, and it does not conduct heat or cold.
The same kind of insert tested against a thinner 3.0mm nail, which is the harder test. This is the highest level of midsole protection in the standard. Worth specifying where fine debris is the hazard rather than big site nails.
You will see these written as S1P, S1PL, S1PS, or on boots as S3L and S3S. A boot carries one of them, never two. If your policy simply says S3, any of S3, S3L or S3S satisfies it. Our product pages shows the certification for each product, decoded into plain English.
What changed in the 2022 standard
EN ISO 20345:2022 replaced the 2011 version and changed four things worth knowing about as a buyer.
- SRA, SRB and SRC are gone. Slip resistance used to be an optional extra you looked for. It is now a basic requirement that every certified boot has to pass, so there is no longer an SRC marking to hunt for. An optional extra test on ceramic tile with glycerine earns the marking SR, which means better than the required minimum.
- S6 and S7 were added, for footwear where the whole boot is water resistant rather than just the upper. S6 is S2 with that added, S7 is S3 with it added.
- Midsole protection split into P, PL and PS, as above.
- Fuel and oil resistance became optional rather than automatic, and is marked FO when it is present. If your job involves standing in diesel, check for FO rather than assuming it.
Boots marked to the old standard are not illegal
Certificates issued against the 2011 version were still being granted into late 2024 and run for five years, so footwear marked EN ISO 20345:2011 is legitimately on sale and legitimately in use for some time yet. It is not a safety problem and you do not need to replace anything early. When you next buy, buying to the 2022 version keeps your PPE policy simple.
The extra letters after the class
The class is followed by any optional protections the boot was also tested for. These are the ones that matter most often in UK workplaces.
Passed the optional test on ceramic tile with glycerine, above the slip resistance every boot must now have.
Tighter control of static than the antistatic requirement built into S1 and above. Specified for electronics, cleanrooms and data centres.
Outsole tested against contact with a 300C surface for 60 seconds. Welding, foundries, roofing.
Insulates the foot from heat coming up through the sole.
Insulates against cold floors. Cold stores and outdoor winter work.
Protects the bones on top of the foot, not just the toes. Asked for on some quarry and heavy plant sites.
Padded protection around the ankle bone.
The test behind the S6 and S7 classes. Can also appear on its own.
Upper resists cutting. Forestry and glass handling.
Outsole tread designed to hold on a ladder rung. New in the 2022 version.
The rubber overlay on the toe survived 8,000 abrasion cycles. New in the 2022 version, and a genuine durability signal on kneeling work.
Outsole resists fuel and oil. Optional since 2022, so check for it rather than assuming it.
Three mistakes worth avoiding
- 1Buying S3 for a dry warehouse. You pay more, the boot is warmer and heavier, and the water-resistant upper does nothing indoors. S1P is the right specification for that job.
- 2Buying S1 to save money when there are nails underfoot. The midsole is the difference between S1 and S1P, and it is the protection most likely to actually be used in a warehouse or on a site.
- 3Writing SRC into a PPE policy. That marking no longer exists under the current standard, so a policy demanding it can no longer be satisfied by new footwear. Specify the class instead, and add SR if you want the enhanced slip test.
S3 boots available now
The default site specification: water-resistant upper, midsole protection and a cleated outsole.
Boots · SJ-BESTBOY
Bestboy
Boots · SJ-MODULOS3M
Modulo S3S Mid
Boots · SJ-DAKAREWS3
Dakar Ew S3
Boots · SJ-MODULOS3MT
Modulo S3S Mid Tls
Boots · SJ-SAFETYSTAR
Safetystar
Boots · COFRA-36386
Funk S3 SRC Safety Boot
S1P trainers and shoes available now
Midsole protection in a lighter build, for dry indoor floors.
Shoes · SJ-CADOR
Cador
Shoes · SJ-MODULOS1PS
Modulo S1Ps Sandal
Shoes · SJ-ECOFITZS1P
Ecofitz S1P Low
Shoes · SJ-MODULOS1PL
Modulo S1Ps Low Perf
Shoes · SJ-SAFETYRUN
Safetyrun
Shoes · SJ-AAKS1PLOW
Aak S1P Low
Common questions
What is the difference between S1P and S3?
S3 adds two things to S1P: a water-resistant upper and a cleated outsole. Both classes have the same 200 joule toecap and the same midsole protection against sharp objects underfoot. If you work indoors on dry floors, S1P gives you the same underfoot protection in a lighter, cooler boot. If you work outdoors or anywhere wet, S3 is the right choice.
Is S3 better than S1P?
S3 offers more protection, but better depends on the job. S3 is the correct specification for outdoor and wet work, and it is what most UK construction sites ask for. In a dry warehouse the water-resistant upper and cleated sole add weight and heat without adding useful protection, so S1P is the better buy there. Neither is safer at the toe, because both use the same 200 joule toecap.
What does the P in S1P stand for?
Penetration resistance, more usually called midsole protection. It means an insert in the sole has been tested to stop a nail or similar sharp object going through and into your foot. Under the 2022 standard the letter also tells you the insert type: P is a steel plate, PL is a non-metallic insert tested with a 4.5mm nail, and PS is a non-metallic insert tested with a thinner 3.0mm nail, which is the toughest of the three tests.
What is S7 safety footwear?
S7 is a class introduced in the 2022 version of EN ISO 20345. It is everything S3 gives you, which is antistatic protection, a water-resistant upper, midsole protection and a cleated outsole, plus a whole-boot water resistance test rather than a test of the upper alone. It is the class to look for if you stand on wet ground all day and find that S3 boots let water in over time.
Do I still need to look for SRC?
No. SRA, SRB and SRC were removed in the 2022 version of the standard. Slip resistance is now a basic requirement that every certified boot has to pass, so it is built into the class rather than added as a marking. A boot marked SR has passed an additional, tougher slip test on ceramic tile with glycerine. If your PPE policy currently demands SRC, it is worth updating, because new footwear cannot carry that marking.
Are steel and composite toecaps rated the same?
Yes. Both have to pass the same 200 joule impact and 15 kN compression tests to be certified, so neither is stronger in the terms the standard measures. The choice between them is about weight, temperature and metal detection rather than protection.
My boots say S3L. Is that different from S3?
It is S3 with a non-metallic midsole insert tested against a 4.5mm nail, rather than a steel plate. S3S is the same idea tested against a thinner 3.0mm nail. All three satisfy a policy that asks for S3, and the non-metallic versions are lighter and do not conduct heat or cold.
Keep reading
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