HRC 1 = 4 cal/cm2
Fire resistant and safety classifications: HRC 1, HRC 2, HRC 3, HRC 4, NFPA 70E, NFPA 2112, ANSI Class 2
HRC refers to Hazard Risk Categories defined by the NFPA 70E standard for electrical safety in the workplace. HRC levels are determined by the minimum amount of calories per square centimeter (ATPV or Cal/cm2) a treated garment must pass through with a 50% probability of a 2nd or 3rd degree burn occurring, thus the protective level of the treated clothing. The higher the ATPV, the higher the HRC level attained, the greater the protection.