Flame resistant textile is inherently flame resistant and do not disappear with washing, Lenzing FR gives comfort to fabrics, and aramid and nylon blends enhance strength and durability of fabrics, often made into shirts, jackets, trousers, lining of thermal suits, etc.
Plain K2/1
EN ISO 11612
NFPA 2112
https://www.lifesafepro.com/protective-fabric/fr-fabric/flame-resistant-textiles.html