The Rasco FR Knitted cap is constructed from 60% Mod acrylic, 38% Cotton, 2% Anti-Static material. Certified by the UL NFPA 2112 and ASTM F1506  you can rest assured that you will be protected and still comply to wearing FR winter hats under your hard hat. the other standards this hat complies with are CSA Z462, CGSB 155.20 and NFPA 70E.