Rasco FR Carpenter Pants Although these blue denim carpenter pants look like normal work jeans, they are made of special flame resistant materials that could increase a factory worker's chance of surviving a workplace fire. While it is normally good to have as much skin covered as possible when working in a hazard risk area, wearing certain materials just make a burn accident much worse. For example, clothing made of synthetic blends tend to melt on the skin during a fire and increase injuries. Even conventional denim pants act as additional fuel during accidental workplace fires. According to statistics from the National Fire Protection Association (NFPA), it only takes a few seconds of flame exposure for a person to sustain third degree burns. Rasco's fire resistant Blue Denim Carpenter Pants provides an excellent flame resistant, lower layer for hazard risk categories (HRC) reaching level two. The pant's flame resistant materials exceed the standard Arc Thermal Protective Value (ATPV) required for a HRC of two, and its ATPV rating is 15. HRC 2 ATPV 20 CAL/CM^2 100% cotton, NFPA 2112 PANTS RUN SMALL IN THE WAIST, WE SUGGEST ORDERING AT LEAST 1-2" LARGER THAN USUALLY WORN Features Pre-washed 11.5 oz FR denimDouble tool cargo pockets on right legHammer loop & ruler pocket on left legTriple stitched main seamsBoot cut openingHRC 2, ATPV 20 cal/cm^2, NFPA 2112