Weather Protection
EN 343
What EN 343 is
EN 343 is the European standard covering protective clothing against the effects of precipitation — rain, snow, fog, and ground moisture/humidity. It specifies the requirements and test methods for both the materials and the finished, ready-made garment, to ensure workers stay reasonably dry and comfortable when working outdoors in wet conditions.
The current version is EN 343:2019, which updated and expanded the classification system from the earlier EN 343:2003+A1:2007 version. Certifications issued under the older version remain valid, so it’s worth checking which edition a given garment or certificate references, since the two aren’t rated on quite the same scale (more on that below).
Scope
EN 343 applies to garments — jackets, coveralls, trousers, and full ensembles — intended for outdoor use in wet weather. It is commonly specified across construction, logistics, agriculture, utilities, and any other outdoor or exposed working environment. Unlike some other protective clothing standards, EN 343 falls under self-certification: manufacturers can certify compliance themselves, without mandatory sign-off from an external testing/notified body for every product, reflecting its status as a lower-risk category of PPE.
The two core performance parameters
EN 343-certified garments carry two class ratings on their label, conventionally written as “EN 343: X, Y”:
X — Water penetration resistance (waterproofness)
This measures how much water pressure the outer material and seams can withstand before water begins to penetrate through, tested from the outside of the garment.
- Measured in Pascals (Pa) or millimetres of water column (mmH₂O)
- Rated in four classes (1–4), with Class 4 representing the highest waterproofness
- Approximate thresholds commonly cited: Class 1 ≈ ≥8,000 Pa, rising to Class 4 ≈ ≥30,000+ Pa (exact figures should be confirmed against the specific edition of the standard, since the 2019 revision raised the requirements for the top class compared with the 2003 version)
Y — Water vapour resistance (breathability)
This measures how easily moisture and sweat vapour can pass out through the material, tested from the inside of the garment — in other words, how breathable it is.
- Expressed as a Ret value (m²·Pa/W) — the lower the Ret, the more breathable the garment
- Also rated in four classes (1–4), with Class 4 representing the highest breathability
- All layers of the garment (outer fabric plus any lining) are assessed together, which is why an unlined jacket often achieves a higher breathability class than a lined garment made from the same outer fabric — the lining itself can be the limiting factor
Both parameters must be tested and achieve a result for the garment to be CE marked under EN 343 — there’s no pass/fail threshold as such, but both figures must be declared and meet at least the standard’s baseline requirements.
The 2003 vs 2019 revision
This is a common point of confusion, since older stock may still carry the earlier rating:
- Water penetration Classes 1–3 are broadly unchanged between the two versions
- Class 4 for water penetration was introduced/raised in the 2019 version, with higher requirements than the old top class
- Water vapour resistance (breathability) also expanded from 3 to 4 classes, with the specific thresholds for each class shifted slightly — only Class 1 remains consistent across both versions
Optional test: the Rain Tower
Beyond the fabric-level X/Y testing, manufacturers can optionally put the finished, assembled garment through a rain simulation test (sometimes called the “Rain Tower” test):
- The garment is fitted onto a sensor-equipped test mannequin and subjected to simulated rainfall (a commonly cited rate is around 450 litres per m² per hour)
- This checks for leaks at seams, closures, zips, and any garment-specific openings that fabric-only testing wouldn’t catch
- If a garment has undergone this test, an “R” appears alongside the X/Y rating on the label; if it hasn’t, this is shown as an “X” placeholder in that position (not to be confused with the “X” water-penetration class number — context on the label distinguishes the two)
Mechanical and construction requirements
In addition to the two headline water/vapour ratings, EN 343 also sets baseline mechanical requirements for the fabric and finished garment, including:
- Tensile strength (commonly cited minimum: ≥450 N)
- Tear resistance (commonly cited minimum: ≥20 N)
- Bursting strength
- Seam strength — seams must be sealed/taped to prevent water ingress at stitch lines
- A check that the garment design doesn’t include openings (e.g. certain zip or vent designs) that would let water in during normal use
Marking
A compliant garment’s label will typically show:
- The EN 343 standard reference and edition year
- The two-class rating, written as “EN 343: X, Y” (e.g. “EN 343: 4,4”)
- An “R” or “X” indicating whether the optional Rain Tower test was carried out
Correct use and care
- All fastenings, flaps, and closures should be done up correctly — an EN 343 rating reflects the garment used as designed, not partially open or unfastened.
- For genuine wet-weather protection, EN 343 garments are often worn as part of a complete waterproof system (jacket and trousers together), rather than relying on a single garment to cover the whole body.
- Higher breathability (lower Ret / higher Y class) allows longer comfortable wear without a thermal lining, which matters if the garment will be worn for extended periods without additional insulation.
- As with other technical fabrics, waterproof/breathable performance can degrade with wear, washing, or damage to coatings or membranes, so garments should be inspected periodically.
What EN 343 does NOT guarantee
- It does not address thermal insulation against cold — a garment can be highly waterproof and breathable under EN 343 while offering little to no warmth; cold protection is covered separately under EN 342, and the two are frequently combined in a single garment with dual certification.
- A high water penetration class does not automatically mean high breathability, or vice versa — the two ratings are independent, and a garment excellent on one axis can be mediocre on the other (e.g. a heavy PVC-coated garment might reach Class 4 waterproofness but a low breathability class).
- Because EN 343 is self-certified, the rigour behind a manufacturer’s declared class can vary — checking the specific test data or third-party lab reports behind a garment’s rating is worthwhile for critical applications, rather than relying on the label alone.
Quick summary
| Parameter | What it measures | Rating scale | Notes |
|---|---|---|---|
| X — Water penetration | Waterproofness of outer material/seams | Class 1–4 (4 = best) | Class 4 threshold raised in EN 343:2019 |
| Y — Water vapour resistance | Breathability (Ret value) | Class 1–4 (4 = best) | Lower Ret = more breathable; tested with all layers combined |
| Rain Tower (optional) | Leak testing on finished garment | “R” if tested, “X” if not | Simulates real rainfall on the assembled garment |
| Mechanical | Tensile/tear/burst/seam strength | Minimum thresholds | Ensures durability alongside weatherproofing |
| Certification route | — | Self-certified | Lower-risk PPE category vs. Category III standards |
| Doesn’t cover | Thermal insulation (cold) | — | See EN 342 for cold protection |