According to NFPA, the PPE categories are as follows: Category 1: Requires a minimum arc rating of 4 cal/cm². Typical personal protective equipment ncludes arc-rated shirts and pants, and an arc-rated face shield. Category 2: Requires a minimum arc rating of 8 cal/cm².

Arc flash PPE is categorized based on its arc rating, which indicates the amount of incident energy it can protect against. The minimum requirements for PPE categories are as follows: Category 1: 4 cal/cm², Category 2: 8 cal/cm², Category 3: 25 cal/cm², and Category 4: 40 cal/cm².