Safety Footwear Ratings Explained: SB, S1, S1P, S3 and the 2022 Codes

SB to S7: the categories in one table

The categories build on each other: every step keeps what the one below it had and adds more. The standard also splits footwear by construction. Class I is made from leather and other materials. Class II is entirely vulcanised rubber or entirely moulded polymer, which on most sites means wellingtons. S1, S2, S3, S6 and S7 apply to Class I; S4 and S5 to Class II.

The L and S suffixes arrived in 2022, and both describe a non-metal puncture-resistant insert. On a category that includes an insert (S1P, S3, S5, S7), no suffix means a metal plate. Do not confuse the trailing S with the one at the front: S3S reads as “category S3, insert type S”.

The 200 J toecap: steel, composite and no toecap at all

Every toecap under EN ISO 20345 is tested to at least 200 joules of impact and 15 kilonewtons of compression. In plain terms, 200 J is roughly a 20 kg mass dropped from just over a metre onto the toe, and 15 kN is a load of about one and a half tonnes. After the test there must still be room for the toes. The threshold does not change with the category, so an SB and an S7 share the same toecap test.

Steel and composite toecaps have to pass the same 200 J and 15 kN test, so the standard treats neither as the safer option. They differ in weight, in how much heat or cold they pass to the foot and in how they behave at a metal detector. To reach the same strength a composite cap is usually a little thicker, which people with broad feet sometimes notice at the fitting.

Two neighbouring standards cause most label mix-ups. EN ISO 20346 covers protective footwear with a toecap tested at 100 J and 10 kN; its categories start with P (PB, P1, P2, P3… and, since 2022, P6 and P7). That P has nothing to do with the puncture-resistance symbol. EN ISO 20347 covers occupational footwear with no toecap requirement at all; its codes start with O (OB, O1, O2, O3… plus O6 and O7 from 2022). In a laboratory or a hospital ward with no falling or crushing hazard, a closed-heel, slip-tested O-class shoe may be enough. That call belongs to the risk assessment. Where toe protection is needed, a 20347 shoe is no substitute.

Puncture-resistant midsoles: P, PL and PS

A puncture-resistant insert sits between outsole and insole and stops nails, screws or broken glass reaching the foot. Under the 2011 edition, metal and non-metal inserts carried the same P. The 2022 edition separates them: P now means a metal plate only, and non-metal inserts are marked PL or PS.

The difference is the test nail. P and PL are tested with a 4.5 mm nail, and the insert must hold at least 1,100 newtons without being pierced. For PS the nail drops to 3.0 mm. A finer tip concentrates the load on a smaller point, which makes it a harder test for a non-metal insert. The user information in the standard reaches the same conclusion: where the hazard is thin, small-diameter objects, PS is likely the better fit than PL.

A metal plate's resistance depends less on how thick or sharp the object is. The catch is coverage: because of the way shoes are built, the plate often stops short of the edge of the sole. Non-metal inserts are lighter and more flexible and protect more of the sole, but how well they hold varies more with the diameter, shape and sharpness of the object. On a formwork strip-out, where thin nails are everywhere, S3S or a steel-plated S3 makes sense. At a plant with metal detectors at the gate, a steel plate and a steel cap both cause trouble; ask for a composite cap with an L or S suffix, and S where thin nails are also a risk.

A lab value is a limit, not a guarantee. A thinner object or a heavier load raises the chance of penetration.

SRA, SRB, SRC and the new SR slip marking

“S3 SRC” is written in the 2011 language. SRA meant the sole had been tested on ceramic tile wetted with a soap solution (sodium lauryl sulphate), SRB on a steel plate with glycerine, and SRC meant it passed both. Because it covered both surfaces, SRC was the most complete slip marking a 2011 label could carry.

The 2022 edition dropped all three and took the steel surface out of the test. The ceramic tile and soap test is now a basic requirement for every shoe and carries no symbol. Heel forward slip must reach a coefficient of friction of at least 0.31, forepart backward slip at least 0.36. Footwear that also passes on ceramic tile with glycerine is marked SR, with thresholds of 0.19 and 0.22. Special soles on which the test cannot be run, such as spiked ones, are marked Ø.

So an SRC label on the shelf today tells you the shoe was certified to the 2011 edition. It does not map one-to-one onto the 2022 SR, because the test surface and method changed. For floors with oil or grease on them, such as commercial kitchens or lines where lubricant drips, ask for SR. And keep in mind that the coefficient was measured in a lab. A tread packed with mud, a worn pattern or the wrong floor cleaner will pull it down on site.

Additional symbols: A, E, HRO, WR, CI and the rest

The S code is the base package. Site-specific hazards are covered by the letters added after it, and one shoe can carry several. For someone working the loading dock of a cold store, a line such as “S3 CI SR” reads well: a puncture-resistant, water-resistant S3 with cold insulation in the sole and extra grip on oily floors.

Do not read the A symbol as electrical protection. The user note in the standard is explicit: “Antistatic footwear is not suitable for work on live electrical installations.” The requirement for electrically insulating footwear was removed from this standard in 2022; insulating footwear is certified separately under EN 50321.

What changed between EN ISO 20345:2011 and 2022

The 2022 edition was published in March 2022 and replaced the 2011 text. It entered the EU list of harmonised standards in May 2023, and the 2011 edition was withdrawn from that list on 11 November 2024. A good deal of 2011-marked stock is still in stores and on sites, so anyone buying footwear needs to read both languages.

S3 causes the most confusion. A 2011 S3 may have a non-metal insert, usually textile; tested to 2022, the same boot would be marked S3L or S3S. In the 2022 language a plain “S3” means a metal plate, so if you need metal-free footwear, write the full code with its suffix.

The main changes:

• Slip: SRA, SRB and SRC are gone. The ceramic tile and soap test is mandatory for all footwear, and the extra glycerine test is marked SR.
• Midsoles: P now means metal only. Non-metal inserts split into PL (4.5 mm nail) and PS (3.0 mm nail), which is where S1PL, S1PS, S3L, S3S, S5L and S5S come from.
• Water: WRU became WPA. The whole-shoe WR test got stricter; 2011 allowed a wetted area of up to 3 cm², 2022 allows no water inside.
• New categories: S6 (S2 + WR) and S7 (S3 + WR).
• Fuel oil resistance (FO) left the categories and became an optional symbol.
• New optional tests: ladder grip (LG) and scuff cap abrasion (SC).
• The electrical insulation requirement was removed from the standard.
• Manufacturers must give an obsolescence date or period in their information, and the marking shows at least the year and month of manufacture.

S1P vs S3: matching the rating to the site

Both have a 200 J toecap, a closed heel, antistatic properties, an energy-absorbing heel and a puncture-resistant insert. They part ways in two places. The S3 upper is tested for water penetration and absorption (WPA); S1P has no such requirement, which is why some S1P models use breathable mesh uppers. The S3 outsole is also cleated, with tread deep enough to bite into mud and loose ground. On dry, level floors S1P is lighter and cooler. Outdoors, in wet or muddy conditions, S3 is the one to pick.

The pairings below are a starting point, not a decision. The category rests on the employer's risk assessment and the rules that apply where the work is done; in the EU, safety footwear is placed on the market with a CE mark under Regulation (EU) 2016/425. The rating should answer the hazards that assessment lists.

• Construction and civil works: S3 or S3S, usually as a boot. Formwork strip-out brings thin nails, excavation brings water and mud. Floor layers who spend the day kneeling can look for SC; crews on scaffolds and ladders for LG.
• Warehousing and logistics: S1P handles most work on dry concrete. Add S3 and CI where the dock takes rain or the cold store runs with condensation. For pickers who walk all shift, weight decides, and a composite cap with a non-metal insert (PL or PS) takes some of it off.
• Commercial kitchens: puncture risk is low, slip risk high. Where heavy pans and dropped knives are a hazard, an S2 with SR is a sensible choice. In permanently wet areas such as the pot wash, look at Class II (S4). The reason is in the user note: leather Class I footwear left in the wet for long stretches soaks up moisture and can turn conductive, whereas rubber or polymer Class II stands up to wet conditions. If the risk assessment rules out a toecap, a slip-tested O-class shoe under EN ISO 20347 is an option.
• Welding and metalwork: look for HRO, because hot spatter should not melt the sole. Mesh uppers do not belong here. S1P HRO suits dry floors indoors, S3 HRO outdoor or wet areas. Plan the shoe together with the trousers: a flap or quick-release closure and a hem that falls over the boot. Foundry and welding risks have their own series, EN ISO 20349; where molten metal splashes, check against that standard.

Fitting, and the signs that a pair is finished

The right rating in the wrong size protects nobody, because the shoe ends up unworn or half-laced. Fit in the afternoon, with the socks worn at work, and try both feet. Standing, the toes must not touch the toecap; a rigid cap will not give the way leather does. The heel should not lift as you walk. A winter boot gets fitted with the thick socks it will be worn with.

The insock supplied with the shoe was part of the certified test. The standard's user note says it should only be replaced with an equivalent from the original manufacturer or an insole shown to work with that shoe. A random insole can eat into the space under the toecap and change the electrical resistance. For workers who need orthotics, the 2022 edition added Annex A, which covers safety footwear adapted to an individual.

On bulk orders the specification does most of the work. When you ask Formasan for a safety footwear quote, give the full code with its symbols (for example S3S SR HRO), the toecap type, boot or shoe, and the size split from your fittings; that gets the first proposal close to the right model.

The shoe, not the calendar, says when it is finished. Retire the pair as soon as you see any of these:

• The toecap has taken a hit, is dented, or shows through a torn upper.
• The forepart cleats are worn flat and the grip has gone on oily floors.
• The upper is separating from the sole, there is a deep crack, or a cut reaches the insert.
• An antistatic shoe reads outside its range at a periodic resistance check.
• Polyurethane-soled stock that sat in storage is crumbling or cracking; the month of manufacture on the label tells you how old the stock is.