The Foul Weather Clothing Safety Standard EN 343 is a European Standard for protective clothing which is designed to be worn in wet weather. It takes into consideration the construction of the garment along with the fabric used.
There are two main category ratings that make up EN 343. The first looks at how waterproof the item is, and the second measures its breathability. So for instance, an EN343 class 3:3 label means it has the highest possible rating for both waterproofness and breathability.