Safety footwear codes can look like alphabet soup. This guide explains the main EN ISO 20345 safety boot and shoe ratings in plain English, helping you compare footwear before choosing a pair for the job.
Quick note: A higher number does not automatically make a boot suitable for every workplace. Always check your employer’s risk assessment and the individual product specification.
What does EN ISO 20345 mean?
EN ISO 20345 is the standard used for safety footwear fitted with a protective toe cap. The toe protection is tested against an impact energy of 200 joules. The current standard is EN ISO 20345:2022, although footwear certified to earlier versions can still be encountered.
Safety footwear categories at a glance
SB: basic safety footwear
SB footwear meets the basic requirements of EN ISO 20345, including a 200-joule protective toe cap. Other protection, such as water resistance or penetration resistance, must be stated separately.
S1: for dry indoor conditions
S1 adds a closed heel area, antistatic properties and energy absorption in the heel. It is commonly used for dry workplaces such as warehouses, workshops and light manufacturing.
S1P: S1 with penetration resistance
S1P is a familiar marking from the earlier standard. It combines S1 features with resistance to penetration through the sole. Under EN ISO 20345:2022, the type of penetration-resistant insert and test nail is identified more precisely by P, PL or PS.
S2: added water-resistant upper
S2 includes the S1 features plus resistance to water penetration and absorption through the upper. It does not, by itself, mean that the complete boot is waterproof.
S3: outdoor-ready protection
S3 combines the main S2 features with penetration resistance and a cleated outsole. Under the 2022 standard, S3 indicates a metal penetration-resistant insert tested with a 4.5 mm nail.
S3L and S3S: non-metal penetration-resistant inserts
S3L uses a non-metal insert tested with a 4.5 mm nail. S3S uses a non-metal insert tested with a smaller 3.0 mm nail. Both include a cleated outsole and the other core S3-category features.
S6: water-resistant whole footwear
S6 combines S2-level features with WR protection, meaning the complete footwear has been tested for resistance to water entering the boot.
S7, S7L and S7S: water resistance plus penetration protection
These categories combine WR whole-footwear water resistance, a cleated outsole and penetration resistance. S7 uses a metal insert, S7L a non-metal insert tested with a 4.5 mm nail, and S7S a non-metal insert tested with a 3.0 mm nail.
Common additional markings
- SR: slip resistance tested on a ceramic tile surface with glycerine.
- FO: outsole resistance to fuel oil.
- HRO: resistance of the outsole to hot contact.
- WR: water resistance of the complete footwear.
- WPA: resistance of the upper to water penetration and absorption.
- CI: cold insulation.
- HI: heat insulation.
- M: metatarsal protection.
- AN: ankle protection.
- CR: cut resistance.
- C: partly conductive footwear.
- LG: ladder grip.
- SC: scuff-cap abrasion protection.
Which rating should you choose?
- Dry warehouse or workshop: S1 may be suitable where penetration and water hazards are not present.
- Dry work with sharp objects underfoot: look for suitable penetration resistance, such as S1P under the earlier standard or an appropriate P, PL or PS category under the 2022 standard.
- General outdoor construction: S3, S3L or S3S is commonly considered because these categories combine water-resistant uppers, penetration protection and cleated outsoles.
- Wet environments: check for WR whole-footwear protection rather than assuming that an S2 or S3 upper makes the complete boot waterproof.
The right footwear depends on the hazards present, including impact, penetration, slipping, water, heat, cold, chemicals and electrical risks. Check the product label and declaration of conformity, and follow the safety requirements for your workplace.