Safety Boot Ratings Explained

Safety footwear ratings under EN ISO 20345 are cumulative: each step up the ladder keeps everything below it and adds more. SB is the baseline, a toe cap that withstands a 200 joule impact. S1 adds a closed heel, an antistatic build, an energy-absorbing seat region and a fuel and oil resistant outsole. S2 adds a water-resistant upper on top of that, and S3 adds a penetration-resistant midsole and a cleated, grippy outsole. That is why S3 has become the default spec on UK construction sites: it covers impact, puncture, wet ground and slips in one certificate.

The 2022 revision of the standard refined how midsoles are tested. Where the old P marking always meant a steel plate, the newer certificates distinguish the material: a letter S after the rating (as in S1PS or S3S) means a metallic insert, while an L (as in S3L) means a non-metallic insert tested against a finer nail. In practice both protect your sole; the non-metallic versions are lighter, flex more freely and do not conduct heat or cold. If you want to avoid metal in the boot entirely, our metal-free safety boots collection gathers the fully non-metallic options.

The 2022 standard also introduced S6 and S7 for whole-boot water resistance. A water-resistant upper (the S2 and S3 requirement) keeps splashes and surface water out; a fully water-resistant boot (S6 or S7) is tested so the whole boot keeps water out, which matters for groundworks, agriculture and anyone standing in standing water. S7S and S7L follow the same midsole lettering as above. You will find these alongside membrane-lined S3 styles in our waterproof safety boots collection.

Choosing is simpler than the codes suggest. Dry indoor trades are well served by S1P trainers and shoes. General UK site work points to S3 safety boots. Wet ground, winter groundworks and farming point to S7 or a membrane-lined S3. Slip markings (SR on newer certificates, SRA, SRB and SRC on older ones) tell you the sole passed slip testing, worth checking for smooth or greasy floors. Whatever the rating, fit decides whether you will actually wear them all day, and our size and fit guide covers length, width and lacing.