EN ISO 20345 sets the requirements for safety footwear. Its defining feature is a protective toe cap withstanding a 200 joule impact and 15 kN compression. That is the only mandatory element — everything else is added through the class.
The 2022 revision: what changed
The 2022 revision reworked the class system substantially. Penetration resistance now splits three ways depending on the insert material and test, waterproof classes S6 and S7 were added, and slip resistance — previously flagged separately as SRA/SRB/SRC — became mandatory for all footwear.
The three penetration options
| Code | Insert | Nail diameter |
|---|---|---|
| P | Steel plate | 4.5 mm |
| PL | Non-metallic (textile) | 4.5 mm |
| PS | Non-metallic (textile) | 3.0 mm |
PS is the tougher option: a thinner nail penetrates more easily, so passing the 3.0 mm test is harder. A non-metallic insert is lighter, does not conduct cold and covers the whole sole, unlike a steel plate which leaves the edges exposed.
The main classes
| Class | Properties |
|---|---|
| SB | Basic — 200 J toe cap only |
| S1 | SB + closed seat region, antistatic, energy absorption |
| S2 | S1 + water penetration resistance of the upper |
| S3 | S2 + penetration resistance (P) + cleated outsole |
| S3S | S3 with the non-metallic 3.0 mm insert |
| S4 | Fully moulded (rubber/polymeric), waterproof |
| S5 | S4 + penetration resistance + cleated outsole |
| S6 | S2 + whole-shoe water resistance (WR) |
| S7 | S3 + whole-shoe water resistance (WR) |
| S7S | S7 with the non-metallic 3.0 mm insert |
Additional markings
- A
- Antistatic — resistance between 0.1 and 1000 MΩ
- E
- Energy absorption in the seat region (20 J)
- WR
- Water resistance of the whole shoe
- WPA
- Water penetration and absorption of the upper
- HRO
- Outsole resistant to contact heat (300 °C for 60 s)
- HI
- Heat insulation of the sole complex
- CI
- Cold insulation of the sole complex
- M
- Metatarsal protection
- AN
- Ankle protection
- CR
- Cut resistance of the upper
- SC
- Scuff cap abrasion resistance
- FO
- Fuel- and oil-resistant outsole
- LG
- Ladder grip
A detailed class matrix and a comparison with the 2011 edition are set out in our safety classes guide.
