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. Details: 100% flame resistant cotton fleece knit 405 gsm, 12oz Aramid high tenacity flame resistant thread, flame resistant ribbed waistband and cuffs, resin zipper on aramid tape, overlock seams and kangaroo pockets. This shirt meets the following standards: HRC2 - Arc rating: ATPV 20, 9 cal/cm2, NFPA 70E-2004, NFPA 2112-2012, ASTMF 1506-2010a. Material: Cotton, Nylon.