BLÅKLÄDER flame-resistant trousers have a unique pocket system with removable pockets, which can be switched around or replaced when one wears out. BLÅKLÄDER flame-resistant clothes are also certified to: EN 531 - workwear for industrial workers who are exposed to extensive heat. EN 470-1 - clothes for welders. Note that the fabric will be harmed by an open flame, but will not catch fire.