This flame-resistant cotton henley shirt features unique Urea Buttons that are very resistant to heat and will not burn. Looped Knit Yarns are extremely flexible; providing comfortable stretch. Comfortable Tagless Neck eliminates annoying scratching and irritation. Flame-Resistant Aramid Threads offer durability, strength, & added protection. Tested to retain protection through 100 washes. 7 ounce flame-resistant cotton jersey knit, Premium heat-resistant urea buttons ASTM F1506, NFPA 2112 certified, UL classified NFPA 70E certified, ATPV 12 cal/cm (PPE CAT 2)