This standard specifies requirements for garments designed for use in rain, snow, fog, and humid environments.

According to the latest version, EN 343:2019, garments and seams are tested for:

• Water penetration resistance (waterproofness) – Classes 1 to 4
• Water vapor resistance (breathability) – Classes 1 to 4
  Where Class 4 represents the highest level of performance.
  To achieve CE marking under EN 343, the garment must meet requirements for both tests.

Breathability and Construction

Breathability is influenced by garment construction:

• Unlined garments often achieve EN 343 Class 4:4 (same as outer layer).
• Lined garments with the same outer layer may only achieve, for example, EN 343 Class 4:2, because the lining affects water vapor permeability.

The standard also includes an optional rain tower test for finished garments to assess waterproofness under simulated rainfall.