Fire zero by Wolverine flame resistant garments are engineered to offer you the protection needed while still providing the comfort, quality and durability you have grown to expect from Wolverine. Wolverine products are completely flame resistant, double dipped in an FR treatment to ensure all materials are properly coated for your safety, minimal shrinkage limited to 3 percent or less, low formaldehyde using up to 75 percent less than Wolverine competitors while still maintaining certified protection from heat and arc flash hazards, and Wolverine use a type of nylon engineered with heavier yarns to provide a stronger fabric. The FireZero Flame Resistant Twill Long Sleeve Shirt features: Flame resistant twill, 90% pima cotton, 10% high tenacity nylon 200gsm, 5.8 oz Aramid high tenacity flame resistant thread, button-down collar, flame resistant plastic buttons, two chest pockets with flap and button-through closure. This shirt meets the following standards: HRC1 - Arc rating: ATPV 7. 7 cal/cm┬▓, NFPA 70E-2004, NFPA 2112-2012, NFPA 1975-2009, ASTMF 1506-2010a, OSHA 29 CRF 1910. 269, CAN/CGSB 155. 20-2000, CAN/CGSB 155. 22-97, EN ISO 11611:2008, EN ISO 11612:2008, EN ISO 14116:2008. Material: Twill, Nylon.