EN ISO Standards Explained (Safety Footwear)

When it comes to ensuring the safety and protection of your feet in hazardous environments, it's crucial to choose the right safety footwear. 

To help you make an informed decision, understanding safety footwear standards and the EN symbols associated with them is essential. 

This page aims to provide you with a comprehensive overview of the EN symbols commonly found on safety footwear, enabling you to select the appropriate footwear for your specific needs.

Safety Boots - Safety Shoes - Safety Trainers

EN ISO 20345:2022 Safety Footwear

This standard applies to safety footwear that provides protection against impacts, punctures, and various other hazards. 

Footwear meeting this standard is classified into different safety categories, each denoted by a specific code:

• SB: Basic Safety Footwear: Provides toe protection against impacts up to 200 joules and compression up to 15,000 newtons.

• S1: Safety Footwear: Similar to SB, with the addition of antistatic properties and energy absorption in the heel region.

• S1P: Safety Footwear with Penetration Resistance: Includes all features of S1, with the added protection against penetration by sharp objects.

• S2: Safety Footwear with Water Resistance: Offers all the characteristics of S1, plus resistance to water penetration.

• S3: Safety Footwear with Enhanced Water Resistance and Penetration Resistance: Combines the features of S2 with increased penetration resistance and additional protection against the risks posed by sharp objects.

S3S: specifies that the boot has non-metallic penetration resistance, tested with a 3mm diameter nail.

S3L: specifies that the boot has non-metallic penetration resistance, tested with a 4.5mm diameter nail.

• S4: S4 offers the same features as S1-rated footwear but is made from a rubber upper or entirely-moulded polymer, such as a Wellington boot. S4-rated footwear offers waterproof and leak-proof properties.

• S5: S5 offers the same features as S4-rated footwear as well as additional protection in the form of midsole penetration resistance.

• S6: S6 offers the same features as S2-rated footwear plus additional protection in the form of water resistance for the whole piece of footwear. The S6 rating was introduced within the EN ISO 20345:2022 standard.

• S7: S7 offers the same features as S3-rated footwear plus additional protection in the form of water resistance for the whole piece of footwear. The S7 rating was introduced within the EN ISO 20345:2022 standard.

S7S: specifies that the boot has non-metallic penetration resistance, tested with a 3mm diameter nail.

S7L: specifies that the boot has non-metallic penetration resistance, tested with a 4.5mm diameter nail.

In addition to the primary EN symbols, supplementary symbols provide information about additional features and properties of safety footwear.

Some commonly used symbols include:

• E: Indicates that the footwear complies with the standards for energy absorption in the heel region.

• A: Antistatic footwear.

• M: Metatarsal protection.

• WRU: Denotes water resistance of the upper material.

• WR: Whole shoe waterproof.

• P: Indicates penetration resistance of the outsole.

• HI: Specifies that the footwear provides insulation against heat.

• CI: Indicates that the footwear provides insulation against cold.

• FO: Resistance to oil and petrol.

• HRO: Denotes resistance to heat on the outsole.

• SRC: Specifies that the footwear meets the highest level of slip resistance requirements on both ceramic and steel surfaces.

• S: This standard specifies that the boot has non-metallic penetration resistance, tested with a 3 mm diameter nail (commonly seen on S3S or S7S boots).

• L: This standard specifies that the boot has non-metallic penetration resistance, tested with a 4.5 mm diameter nail (commonly seen on S3S or S7S boots).

• SC: Scuff Cap — Reinforced toe area to improve durability and resistance to abrasion, extending the life of the footwear in high-wear environments.

• LG: Ladder Grip — Indicates that the footwear has enhanced grip features in the heel or sole area, improving stability when climbing ladders.

• AN: Ankle Protection — Provides additional padding or structure to protect the ankle from impacts or twisting.

• CR: Cut Resistance — Footwear includes materials designed to resist cuts and lacerations.

• ESD: Electrostatic Discharge — Controls static electricity, protecting sensitive electronic components.

• DG: Dielectric Insulation — Footwear suitable for work involving electrical hazards, tested for insulation against electric shock.

• PL: Perforation Resistant (Lightweight) — Uses non-metallic, flexible midsole protection instead of steel.

• PR: Puncture Resistant — Provides high resistance against sharp object penetration, often using steel midsoles.

• SR: Slip Resistant — General slip resistance, though not necessarily to the full SRC level.

• OB/OC: Occupational Footwear — For non-safety footwear used in environments where toe protection isn’t required but other safety features may apply.

These provide more specific information about performance in modern work environments and better align with evolving materials and testing methods.

• SC: Scuff Cap — Reinforced toe area tested for abrasion resistance, enhancing durability in kneeling or rough-surface work.




• LG: Ladder Grip — Specifies improved grip at the heel area to ensure secure footing on ladder rungs.

• WP: Waterproof (Whole Footwear) — Confirms full waterproofing, not just resistance of the upper, verified through whole-shoe testing.

• SR: Slip Resistant (Single Test) — Replaces older SRA/SRB/SRC categories with a simplified slip test standard under updated methods.

• SRA/SRB/SRC (Legacy): Previously indicated slip resistance on different surfaces; now replaced by SR under EN ISO 20345:2022.

• SC + LG Combination: Found on advanced footwear models, indicating both enhanced abrasion protection and ladder stability features.

• S3S / S7S: Revised composite safety classifications reflecting new penetration-resistance test methods (3 mm and 4.5 mm nails respectively).

• WR / WRU Update: Distinction clarified — WR applies to the entire shoe, while WRU refers only to the upper material.

View All Safety Footwear at Tuffshop

This guide is for informational purposes.

For the latest advice on PPE regulations visit the HSE.gov website