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27 September 2026

EN 343 Explained: Waterproof Workwear Classes

EN 343 is the European standard for protective clothing against rain. Every compliant waterproof jacket, over trouser and coverall carries its rating beside an umbrella pictogram. The current edition is EN 343:2019, which added a fourth class and an optional rain tower test to the earlier version.

Reading the label

  • First number: water penetration resistance, class 1 to 4.
  • Second number: water vapour resistance (breathability), class 1 to 4.
  • Letter: R if the finished garment passed a rain tower test, or X if that test wasn’t done. A top-rated garment reads 4 : 4 : R.
Water penetration classes (EN 343:2019, as summarised by SATRA and Sioen)
ClassMinimum water penetration resistanceTested
18,000 PaFabric before pre-treatment
28,000 PaFabric after pre-treatment
313,000 PaFabric after pre-treatment
420,000 PaFabric and seams after pre-treatment

Pre-treatment simulates wear, such as abrasion, flexing and washing, before the test. So the higher classes show how the garment performs after use, not just when new.

Breathability (water vapour resistance) classes: lower Ret means more breathable
ClassRet (m²·Pa/W)In practice
1Above 40Low breathability. The standard advises limiting wearing time.
2Above 25, up to 40Moderate
3Above 15, up to 25Good
415 or belowHighest breathability

The rain tower test (R)

Classes 1 and 2 are fabric tests. The optional rain tower test puts the finished garment, with its zips, seams and pockets, under simulated rain. An R on the label means it passed. That is the closest thing in the standard to a real downpour.

Older labels

Garments certified to the earlier edition, EN 343:2003+A1:2007, show only two numbers (for example 3:3), each on a 1-to-3 scale, and no R. The 2019 edition added class 4, shifted the breathability boundaries (only class 1 is unchanged) and introduced the rain tower test, so a 2003 "3:3" is not directly comparable with a 2019 rating.

Choosing by class

  • Occasional wear or short spells in rain. A lower water penetration class and breathability class 1 (for example 3:1) is common on PU-coated waterproofs and is acceptable for short use.
  • Active work in regular rain. Look for breathability class 3 or 4 so sweat can escape.
  • All-day heavy rain. Look for 4:4:R, as on most of our GORE-TEX® Workwear.
  • Hi-vis. EN 343 says nothing about visibility. For roadside and rail work, you also need EN ISO 20471; see hi-vis classes explained.

Frequently asked questions

What is the best EN 343 rating?
4:4:R: class 4 for water penetration, class 4 for breathability, and rain tower tested as a finished garment.
What does the R mean on EN 343?
The finished garment passed the optional rain tower test. An X means the test wasn’t carried out.
Is EN 343 the same as waterproof?
EN 343 certifies protection against rain. The water penetration class tells you how waterproof the fabric is, and the breathability class tells you how comfortable it will be to work in.
Does EN 343 cover hi-vis?
No. Hi-vis is EN ISO 20471. Many garments are certified to both.

Standards referred to

Shop this guide

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Class 3 hi-vis GORE-TEX® Jacket rated EN 343 4:4:R. Built for all-day outdoor work in heavy rain. Orange version certified to RIS-3279-TOM.

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GORE-TEX® Product TechnologyOrbit Hudson GORE-TEX® Work Jacket

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Men's 3/4-length GORE-TEX® Jacket in black or navy with a detachable, concealed hood. For wet outdoor work that doesn't need hi-vis.

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