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Safety Footwear Guide - Northern Ireland

Safety Boot Ratings Explained: S1, S3 and S7 Work Boots

A plain-English guide to safety boot ratings - S1, S1P, S3, S3S and S7 under EN ISO 20345. Compare ratings, decode the SRC and WR symbols, and find the right safety boots for your trade. Supplied across Northern Ireland by MHS since 1999.

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S3 - Solid Gear
Solid Gear Adapt
LIGHTWEIGHT - ALL-ROUND PROTECTION

A lightweight S3 safety boot built for all-day site work - water-resistant upper, pierce-resistant midsole and an aggressive SRC grip.

Rating
S3
Toe cap
200J
Grip
SRC
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S3
S3
Solid Gear Adapt
Start here

What do the ratings on safety boots actually mean?

Every safety boot sold in the UK and Ireland is tested against the EN ISO 20345 standard. The rating stamped on the boot - SB, S1, S1P, S3, S3S or S7 - is shorthand for the exact protection it provides, from the toe cap to the midsole to water resistance. Get the safety boot rating right and your team is properly protected and compliant; get it wrong and you are either underprotected or paying for features the job does not need.

Below is every common rating explained, the extra symbols you will see alongside them (SRC, WR, HRO and the rest), and a simple way to choose the right work boots by trade.

The ratings

Safety boot ratings from SB to S7

SB

Basic safety

The baseline. A 200-joule toe cap and nothing more required. Rarely enough on its own for trade work.

SB
S1

Toe cap and antistatic

200J toe cap, antistatic, energy-absorbing heel, oil-resistant sole and a closed seat region. For dry indoor environments.

S1
S1P

S1 plus pierce protection

Everything in S1 plus a penetration-resistant midsole - protection against nails and sharp objects underfoot. Popular on sites.

S1P
S3

The all-rounder

Toe cap, midsole pierce protection, water-resistant upper and a cleated outsole. The most popular trade choice for outdoor and wet work.

S3
S3S

S3 plus extra grip and fuel resistance

A newer tier: all of S3 with stricter slip resistance and fuel-oil resistance built in. Strong choice where floors are wet or oily.

S3S
S7

Top-tier protection

The newer high-spec rating - full water resistance, pierce protection and the toughest slip and grip requirements. For the harshest conditions.

S7

Note: EN ISO 20345:2022 introduced updated codes (such as S3S and S7) alongside the long-standing S1 to S3 ratings, so you may see both on current stock. The protection logic is the same - higher generally means more protection.

The symbols

The extra symbols on the label, decoded

Beyond the main rating, safety boots carry letter codes for specific extra protections. These are the ones you will see most often.
SRCSlip resistancePasses both slip tests - on ceramic with detergent and on steel with glycerine.
PPenetrationPierce-resistant midsole against nails and sharps underfoot.
WRWater resistantWhole-boot water resistance, not just the upper.
WRUWater-resistant upperThe upper material resists water penetration and absorption.
HROHeat-resistant outsoleOutsole withstands brief contact with hot surfaces (300C).
CICold insulationInsulation against cold for outdoor and cold-store work.
HIHeat insulationInsulation against heat from the ground.
MMetatarsalAdded protection across the top of the foot.
ESDStatic dissipativeTighter electrostatic control for electronics and sensitive areas.
Match the boot to the job

How to choose the right safety boots for your trade

Construction and groundwork

Go S3 or S7

Wet, muddy, sharp-object risk underfoot. You want a water-resistant upper, a pierce-resistant midsole and an aggressive grip.

Warehouse and logistics

S1P or S3

Dry indoor floors with manual handling. S1P adds midsole protection; step up to S3 if loading bays get wet.

Food and hygiene

S2 / wipe-clean

Slip-resistant, water-resistant and easy to clean. Look for SRC grip and washable uppers for food-industry settings.

Cold stores and outdoors

S3 CI

Add cold-insulation (CI) for freezer and winter work, plus full water resistance for long outdoor shifts.

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FAQs

Safety boot ratings: common questions

What is the difference between S1 and S3 safety boots?+
S1 boots have a 200-joule toe cap, are antistatic and have an oil-resistant sole, but the upper is not water resistant and there is no midsole protection. S3 adds a water-resistant upper, a penetration-resistant midsole and a cleated outsole, which makes S3 the go-to for outdoor, wet or site work.
What does S1P mean?+
S1P is an S1 boot with added penetration resistance - a protective midsole that guards against nails and sharp objects underfoot. It is a popular middle ground for indoor sites that still carry a puncture risk, without the full water resistance of S3.
What are S3S and S7 ratings?+
S3S and S7 are newer ratings introduced under EN ISO 20345:2022. S3S builds on S3 with stricter slip resistance and fuel-oil resistance, while S7 is a top-tier rating combining full water resistance, pierce protection and the toughest grip requirements for the harshest conditions.
What does SRC mean on a safety boot?+
SRC means the boot has passed both slip-resistance tests: on a ceramic floor with detergent and on a steel floor with glycerine. It is the highest standard slip rating and a good thing to look for if your floors are wet or oily.
Which safety boot rating do I need?+
As a rule of thumb: S1 or S1P for dry indoor work, S3 for outdoor, wet or site work with a puncture risk, and S3S or S7 for the most demanding conditions. Add symbols like CI for cold stores or HRO for hot surfaces. If you are unsure, our team can advise on the right specification for your trade.

Kitting out a team? Explore the full MHS range.

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