S1, S1P, S2, S3, four codes stamped inside almost every safety shoe sold in the UK, and four codes most buyers never actually decode.
Here's the short answer: S1 covers basic toe and static protection for dry indoor work, S1P adds a puncture-resistant midsole, S2 adds a water-resistant upper, and S3 combines both of those upgrades with a cleated outsole for rough, wet ground. These letters are not marketing flourishes, they are pass-or-fail results from EN ISO 20345:2022 lab tests, and wearing the wrong class can breach an employer's risk assessment.
This guide breaks down exactly what each rating tests for, which jobs need which class, and how Xnexz's current S1P footwear fits into that picture.
What Do S1, S1P, S2 and S3 Actually Mean?
S1, S1P, S2 and S3 are protection classes inside the EN ISO 20345 standard, the British and European standard for occupational safety footwear, most recently updated in 2022.
Every class builds on a shared base requirement called SB, safety basic: a toe cap that withstands 200 joules of impact and 15,000 newtons of compression, plus a slip-resistance test that became mandatory for every class in the 2022 revision. From SB, the standard branches upward through four everyday classes, S1, S1P, S2 and S3, each adding specific, testable features rather than vague marketing language.
The diagram below shows how each class actually builds on the last, including a branch most buying guides skip over.
Base level: 200J / 15,000N toe cap, plus mandatory basic slip resistance.
SB + anti-static properties + energy-absorbing heel + closed heel.
S1 + puncture-resistant midsole (P). No water-resistance testing.
S1 + water-resistant upper (WPA). No puncture-resistant midsole.
S2 + puncture-resistant midsole (P) + cleated outsole for uneven ground.
What Protection Does the S1 Rating Require?
S1 adds three features to the SB base: anti-static properties, an energy-absorbing heel that absorbs at least 20 joules of impact, and a fully closed heel area.
These additions guard against static discharge, heel-strike fatigue, and debris entering through an open back. S1 does not include a puncture-resistant midsole or a water-resistant upper.
Dry, controlled indoor environments, retail stockrooms, light assembly lines, and indoor facilities work, typically call for S1 as a minimum.
What Does the "P" Add in S1P?
S1P adds one feature to S1: a puncture-resistant midsole, marked P for a metal insert or PL and PS for a non-metal insert.
The metal P insert resists a minimum penetration force of 1,100 newtons, blocking nails, screws and sharp debris from reaching the sole of the foot. The 2022 revision split non-metal inserts into two grades: PL for a 4.5mm wide test point and PS for a stricter 3mm narrow point.
Xnexz's current Xnexz S1P safety shoes, PulseX and StrideX, carry EN ISO 20345 S1P certification, built around a Kevlar puncture-resistant midsole, a 200-joule aluminium toe cap, anti-static construction, a breathable mesh and microfiber upper, and a shock-absorbing heel, in UK sizes 8 to 10.
What Does S2 Add That S1P Doesn't Have?
S2 adds water penetration and absorption resistance to the S1 base — a treated upper that resists moisture soaking through during a shift. S2 does not include a puncture-resistant midsole.
This is the detail most buying guides get wrong: S1P and S2 are two separate branches from S1, not two steps on the same ladder. A shoe can be S1P without being water-resistant, and S2 without being puncture-resistant. S2 suits damp indoor floors, condensation-prone kitchens, or covered outdoor loading bays where standing water is a risk but sharp debris underfoot is not.
What Does S3 Add, and Does Xnexz Currently Offer It?
S3 combines the S2 water-resistant upper with the S1P puncture-resistant midsole, then adds a cleated outsole for grip on loose, muddy or uneven ground. This combination makes S3 the class most associated with groundworks, roofing, scaffolding, and general outdoor construction. Xnexz does not currently manufacture an S3-certified shoe.
PulseX and StrideX are certified to S1P and designed for suitable light-duty workplaces where S1P meets the site's risk assessment, not for muddy sites, standing water, or heavy construction.
Workers who need S3 should look at a specialist brand such as Portwest, Caterpillar or Amblers, and should always defer to their employer's PPE policy over any product description.
How Do S1, S1P, S2 and S3 Actually Compare?
The table below sets all four classes side by side across the features that actually change between them, so the branch structure above is easy to check at a glance:
| Feature | S1 | S1P | S2 | S3 |
|---|---|---|---|---|
| 200J / 15,000N toe cap | ✓ | ✓ | ✓ | ✓ |
| Anti-static properties | ✓ | ✓ | ✓ | ✓ |
| Energy-absorbing heel | ✓ | ✓ | ✓ | ✓ |
| Closed heel | ✓ | ✓ | ✓ | ✓ |
| Puncture-resistant midsole | – | ✓ | – | ✓ |
| Water-resistant upper (WPA) | – | – | ✓ | ✓ |
| Cleated outsole | – | – | – | ✓ |
What Changed in the 2022 Revision of EN ISO 20345?
The 2022 revision of EN ISO 20345 changed more than the paperwork. Fuel and oil resistance, once a mandatory part of the S1 class, is now an optional add-on marked separately as FO.
A new marking, LG for ladder grip, was introduced for outsoles tested against ladder-rung slipping. Every class, including base-level SB, must now pass a minimum slip-resistance test, closing a gap where some basic shoes previously carried no slip rating at all.
A shoe still labelled to the 2011 version of the standard is not automatically unsafe, but its markings may use older codes such as WRU instead of WPA.
Which Rating Does Your Job Actually Need?
Under the Personal Protective Equipment at Work Regulations, UK employers must assess workplace foot hazards and provide footwear that matches the result of that assessment. The correct class depends on that written risk assessment, not personal preference:
- S1 - dry indoor retail, light assembly or office-adjacent roles.
- S1P - safety shoes for warehouse workers, workshops, or sites with loose screws, nails or metal swarf on the floor.
- S2 - damp kitchens, covered loading bays, or condensation-prone plant rooms.
- S3 - outdoor construction, groundworks, or uneven wet terrain.
Job titles alone do not guarantee suitability, because two employees with the same title can face different underfoot hazards depending on the site.
Always check the risk assessment before choosing a class, and confirm with a safety officer whether a workplace accepts S1P.
How Do You Check a Safety Shoe's Rating Before You Buy?
- Locate the label sewn or printed inside the tongue or on the insole.
- Find the standard number, EN ISO 20345:2022, printed alongside it.
- Read the class code directly after that number: SB, S1, S1P, S2 or S3.
- Check for extra suffix letters such as WR, LG, SRC or CI, which add functions on top of the base class.
- Compare the label against the written risk assessment before adding any shoe to a basket.
A handful of suffix letters turn up on labels alongside the main class and are worth decoding on sight:
For the full pre-purchase checklist, see our UK safety shoe buying checklist.
Common Questions About Safety Shoe Ratings
Is S3 simply better than S1P?
Not automatically. S3 covers more hazards, but it is also heavier and built for wet, uneven ground. A dry warehouse role gains no extra protection from S3 and only carries the added weight.
Can S1P shoes be worn in wet weather?
Occasional splashes are common in most workplaces, but S1P has not been tested for water penetration resistance, so a genuinely wet or damp environment calls for S2 or higher instead.
What is the actual difference between S1 and SB?
SB is the base level with only the toe cap and basic slip resistance. S1 adds anti-static protection, a shock-absorbing heel, and a closed heel on top of that base.
Does a higher letter always mean a safer shoe?
No. S1P and S2 sit at the same level in the standard and simply protect against different hazards, so the right class is whichever one matches the actual risk on site, not the one further down the alphabet.
The Honest Verdict
Reading a safety shoe rating takes under a minute once you know what each letter tests for, and that minute is the difference between certified protection and a shoe that simply looks the part. Xnexz currently builds S1P-certified footwear, PulseX and StrideX, for workplaces where that class meets the site's requirements, not as a replacement for S2, S3 or any specialist boot a riskier role might require. If S1P is what a risk assessment calls for, and a lighter, more modern-looking option than a traditional boot sounds useful, try a pair on a real shift and share honest feedback on the fit, comfort and certification, so the next batch fits real working days a little better.
