EN 343 Protective clothing against the rain
The European standard specifies the requirements for protective clothing against foul weather. The parameters for this standard concern resistance to penetration by water (water impermeability) and water vapour resistance (breathability).
These two parameters are subdivided into 4 classes. For resistance to water penetration the following is required:
| Water penetration resistance (WP) | Class 1 | Class 2 | Class 3 | Class 4 |
| Material before washing | WP ≥ 8.000 Pa ≙ approx. 816 mm water column | – | – | – |
| Material after washing | – | WP ≥ 8.000 Pa ≙ approx. 816 mm water column | WP ≥ 13.000 Pa ≙ approx. 1.326 mm water column | WP ≥ 20.000 Pa ≙ approx. 2.040 mm water column |
| Nähte before washing | WP ≥ 8.000 Pa | WP ≥ 8.000 Pa | WP ≥ 13.000 Pa | – |
| Nähte after washing | – | – | – | WP ≥ 20.000 Pa |
1,000 PA corresponds to approx. 102 mm water column. The water column specifies the water pressure that the upper material can withstand before water penetrates it. The figures specify the load limit at which the first drops penetrate the fabric.
For water vapour resistance:
- Class 1 = Ret > 40
- Class 2 = Ret > 25 ≤ 40
- Class 3 = Ret > 15 ≤ 25
- Class 4 = Ret ≤ 15