Safety footwear: classes S1, S1P, S2, S3 and the SRC marking

What the marking on the shoe tongue means

All safety footwear in the EU is classified according to EN ISO 20345. The basic requirement is a protective toe cap that withstands a 200 J impact and a 15 kN compression in testing. Without a toe cap, a product does not qualify as safety footwear under this standard.

Two related standards are often confused:

• EN ISO 20346: protective footwear with a toe cap for 100 J, marked with codes starting with the letter P.
• EN ISO 20347: occupational footwear without a toe cap, marked with codes starting with the letter O. It is suitable only where the risk assessment identifies no danger of crushing or falling objects.

Within EN ISO 20345, the standard further distinguishes Class I (leather and other materials) and Class II (all-rubber or all-polymeric boots). The markings S1, S2, S3, S6 and S7 belong to Class I, while S4 and S5 belong to Class II. The meaning of individual abbreviations is compiled in the standards glossary.

The toe cap material does not affect the class, as both steel and composite must pass the same test. Composite is usually lighter, conducts heat less and does not trigger metal detectors, while steel is thinner and allows for a narrower shoe toe.

Footwear classes in one table

Note regarding S1: in the 2011 edition it also included outsole resistance to oils and fuels; in the new edition this is a separate marking, FO. If your staff work on oily surfaces, request it explicitly.

Additional markings that determine your choice

The class indicates the base level, while additional markings create the difference between two S3 models:

• P, PL, PS: puncture resistance, tested with a force of 1,100 N. P denotes a metal insole, PL a non-metallic one tested with a 4.5 mm diameter nail, and PS a non-metallic one tested with a thinner 3.0 mm tip. A non-metallic insole is lighter, conducts heat less readily and generally covers a larger part of the sole, while a steel one also stops thinner points. Where staples and thin nails are present, request P or PS, not merely PL. Under the new edition you will therefore encounter markings such as S1PL, S1PS, S3L and S3S, indicating which insole is fitted.
• WR: whole-shoe water resistance test. WRU or WPA refers only to the upper, not to the seams or the tongue up to the top.
• HRO: the sole withstands contact with a 300 °C surface for 60 seconds. HI is thermal insulation of the sole, while CI is insulation against cold, tested at approximately minus 17 °C.
• M is metatarsal protection, AN is ankle protection, CR is upper cut resistance (this is not chainsaw protection, which is covered by EN ISO 17249), SC is toe scuff protection, and LG is ladder grip.

The markings are stamped on the tongue or inside the shoe, together with the standard number, size and date of manufacture. If they are not present there, it is advisable to request documentation before ordering.

SRC and what has changed with the new edition

Under the EN ISO 20345:2011 edition, three slip-resistance markings applied:

• SRA: ceramic tile with detergent solution
• SRB: steel surface with glycerol
• SRC: footwear passed both tests

The new edition of the standard, published by ISO in 2021 and known in Europe as EN ISO 20345:2022, no longer uses these markings. Slip resistance has become a basic requirement for all safety footwear and is tested on a ceramic tile with detergent solution, while the additional SR marking indicates that the model has also passed the more demanding glycerol test.

Both generations of markings are therefore present on the market simultaneously, since certificates issued under the previous edition remain valid until their expiry. If an internal regulation or tender documentation requires 'SRC', a model under the new edition without this marking may be equivalent or better. In a tender, it is better to state the requirement as 'EN ISO 20345, slip resistance in accordance with the current edition of the standard', otherwise you will disqualify suitable offers yourself.

None of these markings say anything about grip on ice. For winter conditions, this property is assessed separately, most reliably with a trial pair in the field.

ESD is not the same as antistatic, and insulating footwear is a third category altogether

Three things that are regularly confused in enquiries:

• Antistatic (A) under EN ISO 20345 means an electrical resistance of between 0.1 MΩ and 1000 MΩ. It dissipates charge from the person while also limiting conductivity. This is a standard property of classes S1 and above.
• ESD is not part of EN ISO 20345 but is assessed under the EN 61340 family of standards, where the limit values are considerably stricter. For footwear alone, a limit of around 100 MΩ is often quoted, and for the person–footwear–floor system, around 35 MΩ, though the requirement of the specific EPA area is decisive. The A marking therefore is not sufficient for a workplace set up for electronics, so explicit proof of ESD compliance should be requested.
• Electrically insulating footwear for work near live parts is manufactured to EN 50321-1 (classes 00 and 0) and is, by purpose, the opposite of antistatic footwear.

The ESD property only works in combination with a suitable floor. Replacing the original insole with your own, thick woollen socks, or dirt under the sole can cancel it out without anyone noticing.

Which class for which worksite

The class is the starting point, but the final decision is based on the workplace risk assessment. A rough guide that applies to most enquiries:

• Assembly, production halls, warehouses without sharp waste: S1 or S1P is usually sufficient, as breathability is more important.
• Work involving moisture indoors, floor washing, food processing: S2, preferably with the SR marking.
• Construction sites, demolition, utility works: S3 is the usual requirement, as it combines a penetration-resistant insole with a profiled sole.
• Concrete, mud, high-pressure cleaning: S5 boots.
• Permanently wet or cold environments: S6 or S7, with the CI marking where needed.

Fit matters more than class, since the same class can rub in a different last. Before placing a larger order, test one pair during the shift it is intended for, and also check the width and the option of replacing the insole. The employer must provide personal protective equipment at their own expense and on the basis of a risk assessment. Models sorted by class are listed in our range of safety footwear.

How to verify that the marking is accurate

Safety footwear as personal protective equipment in the EU is governed by Regulation (EU) 2016/425. As a rule, it falls under category II, which means that the product type must be examined by a notified body.

• The footwear must be permanently marked with: the manufacturer or brand, model designation, size, date of manufacture, standard number and class marking with additional abbreviations.
• An EU declaration of conformity or a link to it must be included, together with instructions in Slovenian.
• The CE mark must appear on the product or its packaging. For category II, the notified body number is given in the documentation and not necessarily next to the CE mark.
• The details on the footwear and in the declaration must match. A mismatch in model or class is grounds for a complaint.

For public procurement, keep the documentation from the moment of delivery, as it is usually harder to obtain later. If you are collecting requirements for several job positions at once, list them by standards and markings rather than model names, and send them in your enquiry.

The class is the starting point, while additional markings indicate whether the shoe is suited to a specific worksite. In a tender, specify the requirement by standard and properties, not by markings from the old edition, otherwise suitable offers may be excluded. Before placing a large order, test one pair in the actual conditions of use.