Safety Footwear Ratings Explained: S1P, S3, S5 and S7
Safety footwear ratings can look like a code, but each marking describes a combination of protection features. This guide explains the main EN ISO 20345 safety footwear classes used on boots, shoes and wellingtons, including S1P, S3, S5, S6 and S7.
The current 2021 revision is also commonly referred to as the 2021 or 2022 update in product information. All S-class safety footwear starts with a protective toe cap tested for 200-joule impact resistance, but the rest of the protection depends on the class and any additional markings.
Use this as a general guide, then check the complete marking, manufacturer's technical data, your workplace risk assessment and the product's own instructions. Browse our Foot Wear collection or return to the Trade Guides hub.
Class I and Class II safety footwear
The classes describe the main footwear construction:
- Class I: footwear made from leather, textile or other materials, such as safety shoes, trainers and standard work boots.
- Class II: footwear made entirely from rubber or polymer, such as moulded waterproof safety wellingtons.
Class I ratings: leather, textile and fabric footwear
| Rating | What it generally adds | Typical use |
|---|---|---|
| S1 | Protective toe cap, closed heel, antistatic properties and energy absorption in the heel. | Dry indoor or sheltered environments where full water protection is not required. |
| S1P | S1 features plus penetration resistance from a protective midsole. | Dry environments where sharp-object risks, such as nails or similar hazards, are present. |
| S2 | S1 features plus water penetration and absorption resistance in the upper, often shown as WPA in newer markings. | Damp or outdoor work where the upper needs some water resistance but full-shoe waterproofing is not required. |
| S3 | S2 features plus penetration resistance and a cleated or profiled outsole. | General construction and outdoor work where sharp-object risks, water-resistant uppers and extra outsole grip matter. |
| S6 | S2 features plus whole-footwear water resistance, shown as WR. | Work requiring more complete water resistance than an S2 or S3 upper can provide. |
| S7 | S3 features plus whole-footwear water resistance, shown as WR. | Outdoor work where both penetration resistance and full-footwear water resistance are needed. |
Class II ratings: rubber and polymer footwear
| Rating | What it generally adds | Typical use |
|---|---|---|
| S4 | Class II waterproof construction with a protective toe cap, antistatic properties and heel-energy absorption. | Fully moulded safety wellingtons for wet environments. |
| S5 | S4 features plus penetration resistance and a cleated or profiled outsole. | Wet or muddy work where both a waterproof boot and underfoot penetration protection are needed. |
What is the difference between WPA and WR?
WPA relates to water penetration and absorption of the footwear upper. It is associated with classes such as S2 and S3. WR refers to water resistance of the whole footwear, so S6 and S7 provide a different level of water protection from footwear that only has a water-resistant upper.
Neither marking means the footwear is suitable for every wet, chemical or contaminated environment. Check the product's instructions and any additional chemical, heat, cold or specialist protection markings.
What do S3S, S3L, S5S and S5L mean?
The newer system can identify different types of non-metallic penetration-resistant inserts. You may see markings such as S3S, S3L, S5S or S5L, as well as S7S and S7L. The suffix matters because the inserts are tested under different conditions. Do not assume that two footwear products are identical simply because both are described as S3 or S7.
P generally refers to the traditional metallic penetration-resistant insert, while PL and PS identify non-metallic options tested under different conditions. Always use the complete product marking and manufacturer's data when comparing footwear.
Which rating should I choose?
There is no single best rating for every job. Start with the hazards:
- For dry indoor work, S1 may be suitable if the risk assessment does not require penetration or water protection.
- For sharp-object risks in dry environments, consider S1P or the appropriate newer equivalent.
- For damp outdoor work, S2 or S3 may be more suitable depending on the underfoot hazard and need for outsole grip.
- For wet or muddy work with sharp-object risks, S5 or an appropriate S7-class product may be relevant, depending on the footwear construction and workplace assessment.
- For full-shoe water resistance in Class I footwear, look for the relevant WR class such as S6 or S7.
These examples are starting points, not automatic recommendations. Consider toe protection, penetration, slip, water, heat, cold, chemicals, electrical risks, comfort, fit and compatibility with other PPE.
What the S rating does not tell you
An S rating does not automatically confirm protection against chemicals, electrical hazards, heat, cold, chainsaws or every slip condition. Look for the additional marking that matches the hazard and check the manufacturer's technical information. Slip performance and additional requirements must be assessed from the complete product marking, not from the S class alone.
Older footwear guides and product descriptions may use SRA, SRB or SRC slip-resistance markings from earlier testing terminology. Do not compare those labels directly with newer product markings without checking the manufacturer's current technical data.
Fit and maintenance matter
Even correctly rated footwear cannot protect as intended if it does not fit, is damaged or is used outside its design limits. Check the toe room, heel hold, width, sole condition, fasteners and any visible damage. Replace footwear when the toe cap, sole, upper or penetration insert may no longer provide the expected protection.
Important reminder
This guide is general information and is not legal advice or a substitute for a competent workplace risk assessment. Standards, markings and manufacturer instructions should be checked against the current product information before footwear is selected for a specific task. Where there is any doubt, ask a competent person or the footwear manufacturer.
Last reviewed: 18 September 2026