When you’re buying safety footwear, there are several things you need to think about. Although style and colour are important (we do still want to look good at work!), these factors take the backseat to safety standards and ratings. You may have seen those abbreviations before when researching safety shoes. Confusing, right? Here’s a decoded guide to safety footwear codes and what you need to look out for.

PPE Regulations in the EU and What You Need to Know

The Personal Protective Equipment (PPE) Regulation 2016/425 replaced the old Directive 89/686/EEC and outlines the standards of PPE, such as safety footwear, in the EU. It’s important for PPE to conform to this particular standard if it’s to successfully protect you from as many hazards as possible.

What Does EN ISO 20345 Mean?

It’s a standard that applies across Europe. Set by the International Organization for Standardization (ISO), it outlines the minimum and optional requirements for safety footwear. This includes slip resistance and features to protect against thermal and mechanical hazards.

Currently, there are two supplementary standards within it: EN ISO 20345:2011 and EN ISO 20345:2012. They cover different levels of protection classes, which we’ll explain below.

The Basic Safety Codes and What They Mean

The two EN ISO standards cover different protection classes. You may have seen terms like “S2 Certified” or “OB Certified”. This merely refers to the extent of a hazard to which the shoe protects against.

So, let’s decode.

EN ISO 20345:2011

SB (Safety Basic)

As the name suggests, this is the basic safety standard for footwear. SB rated shoes offer non-slip soles and steel toe caps to protect against 200-joule impact. They may offer additional safety features which will be indicated via other symbols.


As well as basic toe protection and slip-resistant soles, S1 means the shoe also has antistatic protection, is oil resistant and offers energy absorption in the heel. Other safety features may be added.


All of the features as S1, plus waterproof exterior so prevents water penetration and offers absorption in the upper shoe.


All of the features as S2, plus midsole penetration resistance – meaning that these shoes are puncture proof. For example, a steel midsole prevents sharp objects from piercing through the sole.


All of the features as S1, but is made from a rubber upper or entirely moulded polymer, such as a Wellington boot. This means they’re waterproof and leak-proof.


All of the features as S4, plus midsole penetration resistance to prevent sharp objects from piercing through the sole.

EN ISO 20345:2012


This certified shoe offers non-slip soles (at one of the three levels which we’ll discuss here). It’s possible to have an open heel.


Like OB, this shoe is slip-resistant. It’s also closed heel and offers antistatic protection and energy absorption in the heel area to promote lighter walking.


All of the features of O1, plus water-resistant upper to offer a minimum of 60 minutes protection against water.


All of the features of O2, plus a profiled sole to offer additional comfort. They are also rubber or plastic shoes.

The Slip-Resistant Sole Codes and What They Mean

Slip-resistant shoes are essential for many workplaces. They have deeper tread grooves than standard shoes and so, can grip the floor more securely and prevent slips, trips and falls. Slip resistance is classified via the following codes which indicate where the shoes have been tested on and thus, their level of slip resistance…


Tested on ceramic tile floor wetted with a diluted soap solution.


Tested on steel floor with glycerol.


Tested under both SRA and SRB conditions.

Additional Safety Feature Codes

SB is the basic safety level required, but for footwear that promotes additional safety, look out for these codes…

Antistatic protection (A)

Protects against static electrical charges, such as minor static shocks, but does not offer full protection from exposure to electronics or explosive work. Electrostatic Protection is needed for that.

Midsole penetration protection (P)

Protects feet against sharp objects that may pierce through the sole. Footwear that meets this standard resists a penetration force of 1100N. SB-P, S1-P, S3 and S5 ratings cover this.

Energy absorption (E)

Absorbs energy and pressure in the heel region to relieve pain.

Water resistant upper (WRU)

Upper is resistant to water. Does not apply to rubber or polymeric footwear.

Heat resistant (HRO)

Heat-resistant outsole which resists 300℃ for up to 60 seconds.

Insulation against cold (CI)

Provides insulation against cold for 30 minutes at -20℃.

Insulation against heat (HI)

Insulation against heat for 30 minutes at 150℃.

Electrostatic discharge (ESD)

ESD footwear has been designed for the electronics and explosives industry. It must meet ESD CEI EN 61340-5-1 standards.

In summary, when you’re picking safety footwear, it needs to meet the basic EN ISO 20345 standards. But if you want to be extra safe at work, the optional features are always helpful.

Does Your Role Need Spill Protection and Slip Resistance? Ready to Buy Safety Shoes But Don’t Know Where to Start?

Now that you know what the standards for safety shoes are, you might be looking for tips on how to find and buy the ideal pair for your job role. Slip resistance is one important feature you need to look out for, but there are many others. Check out our guide for help buying spill and slip resistant footwear for different job roles below.