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EN ISO 20345 Safety Footwear Buying Guide

Choosing the right pair of EN ISO 20345 safety boots or shoes can be a challenge for the first time buyer, especially with so much choice on the market – here at Mammoth we have a selection of over 400 pairs of safety footwear available!

When selecting your footwear, there are a number of factors to take into consideration. It is never wise to gamble on the level of protection you need, or what additional benefits will work – The wrong choice could prove to be a disaster; and a pair of boots is far easier to replace than a foot!

So with that in mind, we have put a number of practical tips together in the form of a comprehensive guide, to help you make an informed decision.

Safety Specifications and symbols

When looking at boots you will often see a number of cryptic abbreviations and symbols, but what do they all mean? All safety footwear is governed by an EN ISO 20345 rating, which is often broken into several classes to indicate the level of protection they provide. These will often come with a series of other characters, all of which actually tell you what benefits the particular safety footwear has.


HRO – Contact heat resistant up to 300c.

WRU – Water resistant uppers.

HI – insulated protection from heat.

CI – insulated protection from cold.

E – energy absorbing heels.

A – Antistatic protection.

P – Penetration protection.

CR – Cut resistant uppers.

M – Metatarsal protection


SB – Basic protection with toecap.

S1 – SB + Closed heel area, energy absorbing seat, anti-static properties, resistance to fuel and oil.

S1P – S1 + Penetration resistance.

S2 – S1 + Water penetration and absorption.

S3 – S2 + Penetration resistance, cleated outsoles.

S4 – S1 + Moulded polymer/rubber uppers (wellingtons etc)

S5 – S4 + Midsole penetration resistance.


SRA – Tested on ceramic tiles, saturated with a diluted soap solution.

SRB – Tested on steel, covered in glycerol.

SRC – Tested under SRA and SRB conditions.

This is just a snapshot of some of the benefits that EN ISO 20345 footwear can provide, always check the symbols on each product to make sure it provides the correct safety benefits for you.

Size and Fitment

Making sure you’ve got the correct sizing is important for a comfortable fit, and the same applies more so with safety footwear, as an ill-fitted pair of boots or shoes could do more damage than good. If your chosen footwear is too small, your toes will be raised into an un-natural position, which in terms of a drop or crush hazard could still end up damaging your toes, negating the point of having toecaps in the first place.

On the other hand (or foot), if boots and shoes are too large then you may find that your toes won’t be totally covered by the toecaps, in addition to a poor fit around the ankles which could lead to injury. Some manufacturers, especially those in Europe; tend to use a different size guide for their footwear from the US and the UK.

European and US approximate sizing guide
(UK) – (EU) – (US)
(3) – (36) – (4)
(4) – (37) – (5)
(5) – (38) – (6)
(6) – (40) – (7)
(7) – (41) – (8)
(8) – (42) – (9)
(9) – (43) – (10)
(10) – (44) – (11)
(11) – (45) – (12)
(12) – (46) – (13)
(13) – (47) – (14)
(14) – (48) – (15)

Safety Hardware – Steel, Aluminium or Composite?

While browsing for new EN ISO 20345 footwear, you will often here the terms “Composite” or “non-metallic”. The term composite usually refers to the safety hardware inside the boots, being made from an alternative other than steel – usually a material such as Kevlar. All toecaps regardless of what they’re made of are put through the same rigours during the testing process, conforming them all to EN 12568 standard. All of them will provide the same 200kj impact protection, however there are subtle differences between the three:

Steel Toecaps – Heaviest of the three, also due to the conductive nature of the steel, toes can become hot/cold depending on the environment around them.

Aluminium – Lighter than steel by nearly five times, although much like steel they will conduct heat and electricity.

Composite – Lighter still than Aluminium, non-conductive material so thermal bio-climate inside the footwear remains the same, won’t set off equipment such as metal detectors and scanners – ideal for security roles and airport workers.


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