As sites move into the colder, wetter months, “waterproof” becomes one of the most overused words on a workwear spec sheet. One main European standard exists specifically to put a number on this claim: EN 343:2019. Understanding what is tested and what ratings to look for is useful for anyone buying, briefing or wearing winter PPE, not just for compliance paperwork.

EN 343:2019: protection against rain

EN 343 governs how a garment performs against water penetration and, separately, how well it lets built-up body moisture escape. It doesn’t treat “waterproof” as a yes/no claim. It measures two properties independently and rates each on a scale.

Water penetration resistance (waterproofness) is tested with a hydrostatic head test: water pressure applied to the fabric and seams is increased until it passes through. The result places the garment into one of four classes, from Class 1 up to Class 4, the top tier, which requires the fabric to withstand at least 20,000 Pa of pressure after a cleaning cycle.

Breathability, expressed as a Ret value (resistance to evaporative heat transfer), measures how easily water vapour (sweat) can pass back out through the fabric. This also runs on a four-class scale: a lower Ret value gives a higher class number, meaning the fabric breathes more freely.

The 2019 revision added a third mark to the pictogram: an “R” or an “X”, showing whether the garment was additionally tested under simulated downpour conditions (R) or not (X, an optional test that simply wasn’t carried out).

So, a label reading, for example, 4-1-X tells you: Class 4 waterproofing, the top tier and Class 1 breathability, the lowest tier and no downpour-specific test performed. The 4 for waterproofing and 1 for breathability reflect the usual trade-off where a fully waterproof outer sacrifices some vapour permeability.

Why it matters in winter: wet clothing next to the skin accelerates heat loss significantly. A garment’s tested and classified waterproof performance, rather than a general manufacturer claim, has a direct bearing on cold-weather safety, not just comfort.

Sources:

EN 343:2019 overview – SATRA (satra.com); EN 343 class thresholds – Skanwear (skanwear.com); Supertouch ESS100 and ESS101 datasheets and product pages.

Content created in partnership with Supertouch.