EN 343 is the European standard used for protective clothing against rain and other foul-weather conditions. It helps describe how well a garment resists water penetration and how easily water vapour can pass through the material.
This guide explains the markings in plain English, but the garment label, manufacturer’s instructions, declaration of conformity and workplace risk assessment always take priority.
What EN 343 covers
EN 343 applies to protective clothing designed to protect against precipitation such as rain and snow, fog and ground humidity. It assesses the garment’s materials and construction, including seams and closures, rather than simply measuring whether the outer fabric feels water-repellent.
A jacket can be water-repellent without being certified protective clothing. Look for the EN 343 marking and the accompanying performance classes when you need tested weather protection.
How to read the EN 343 marking
EN 343 performance is normally shown beside the rain pictogram as two numbers:
- X refers to resistance to water penetration, or waterproofness.
- Y refers to resistance to water vapour, often described as breathability.
- R, where shown, refers to an optional rain-tower test. An R replaced by an X means that particular test was not carried out or is not claimed.
For example, a marking such as EN 343:2019 4,3,R indicates a stated class for water penetration, a stated class for water-vapour resistance and a rain-tower result. The exact marking on the garment and its datasheet should be checked because not every garment carries every optional result.
X: resistance to water penetration
The first class describes how well the garment prevents water from passing through the material and seams during the relevant laboratory tests. Under the current EN 343 classification commonly used on newer garments, higher classes indicate a higher level of tested water-penetration resistance.
Do not judge the class from the fabric alone. Seams, zips, storm flaps, hood design, cuffs and the condition of the garment all affect how well rain protection works in practice.
Y: resistance to water vapour
The second class describes resistance to water vapour. This is the garment’s ability to allow moisture vapour from perspiration to pass through the clothing system. Lower vapour resistance generally indicates better breathability, while a higher class on the label represents a higher performance level in the standard’s classification.
Breathability is not the same as ventilation and it does not guarantee that the wearer will stay dry during hard physical work. Base layers, mid-layers, workload, temperature, humidity, wind and how tightly the garment is worn all affect comfort.
Why waterproof and breathable are different
Waterproofness and breathability solve different problems. Waterproofness limits rain entering from outside. Breathability helps water vapour move out from inside. A garment may perform strongly in one area and differently in the other, so check both parts of the marking rather than looking for one overall score.
Even a highly breathable garment can feel wet inside if the wearer is working hard, wearing non-breathable layers or has the vents and closures fully closed. A breathable membrane also cannot remove liquid sweat as quickly as ventilation or an appropriate work-rest plan.
Choosing EN 343 workwear
Match the garment to the task
Consider expected rainfall, exposure time, wind, temperature, physical effort, visibility requirements, chemicals or contaminants and whether the garment must be worn over other PPE. A site-based risk assessment should decide the required protection, not the product name alone.
Check the complete garment
- Confirm the EN 343 marking and the edition or product information supplied by the manufacturer.
- Check water-penetration and water-vapour classes separately.
- Look for taped or sealed seams, waterproof closures, adjustable cuffs and a suitable hood.
- Make sure the cut allows safe movement and works with the other PPE that must be worn.
- Check whether the garment also carries a task-specific marking such as EN ISO 20471 for high visibility.
- Follow the manufacturer’s limits for washing, reproofing, repairs and replacement.
EN 343 and high-visibility workwear
Weather protection and visibility are separate properties. A rain jacket may be certified to EN 343 and EN ISO 20471 at the same time, but EN 343 does not make a garment high visibility. Likewise, a hi-vis garment is not automatically waterproof because it is fluorescent or has reflective tape.
Check that the garment retains the required visible material after layering, fastening, washing and normal wear. For more on the visibility classes, read EN ISO 20471 Hi-Vis Clothing Explained.
Care and maintenance
- Follow the sewn-in care label and the manufacturer’s user instructions.
- Use only the recommended detergents and wash settings.
- Do not use bleach, fabric softener or unauthorised treatments where the manufacturer prohibits them.
- Inspect the outer fabric, membrane, taped seams, zips, cuffs and hood for damage.
- Reproof or repair the garment only using an approved method.
- Replace the garment when leaks, damage, contamination or loss of protective performance cannot be corrected.
Repeated washing, abrasion, body oils, dirt and incorrect drying can reduce water repellency or damage protective components. A garment that once performed well is not permanently waterproof.
Common mistakes
- Assuming a high water-repellent finish is the same as EN 343 certification.
- Looking only at the first number and ignoring vapour resistance and wearer comfort.
- Assuming waterproof clothing is suitable for chemical, electrical, heat or biological hazards without checking the specific standard.
- Covering certified high-visibility material with another garment, harness or equipment.
- Ignoring fit, damaged seams, worn closures or the effect of layers underneath.
Find protective workwear
Browse the Outdoor & Work Wear collection for hi-vis clothing, rainwear and other protective workwear.
For more PPE, workwear and sizing advice, return to the Trade Guides hub.
Safety reminder
This guide is general information only. Always check the current manufacturer documentation, the complete garment marking, your employer’s PPE policy and a competent workplace risk assessment. EN 343 does not replace controls for cold, wind, flooding, chemical exposure or other hazards.
Last reviewed: September 2026.