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 interlock knit, 220 gsm, 6.5oz Aramid high tenacity flame resistant thread, flame resistant ribbed collar and cuffs, front chest pocket, extended tail with side slits. This shirt meets the following standards: HRC2 - Arc rating: ATPV 11, 8 cal/cm┬▓, NFPA 70E-2004, NFPA 2112-2012, ASTMF 1506-2010a. Material: Cotton, Nylon.