Arc Rating: 21 cal/cm Fabrics 12 oz. FR Stretch Denim Features Designed by women for women FR Fabric will NOT melt, drip, or ignite FR protection from electrical arc flash and flash fire hazards Home laundry Leg openings made to fit over work boots Multi-Hazard Protection Prewashed for a soft and comfortable finish Reinforced front and back pockets Standards ASTM F1506 OSHA 29 CFR 1910.269 NFPA 70E-2015 for Arc Flash CSA Z462-15 for Arc Flash (Canada) UL Certified to NFPA 2112 Made in USA