Overview of 4 Different Arc Flash PPE Categories: Find out how different categories of PPE determine the intensity of an arc flash episode, in order to protect workers from electrical hazards. PPE Category 1: The first category represents the lowest level of Arc Rated PPE, requiring only a single layer of arc-rated PPE. PPE Category 2: The second category can also be fulfilled with a single layer of Arc Rated PPE. PPE Category 3: PPE Category 3 and 4 require additional layers of PPE. Arc flash suit hoods are required and rubber insulating gloves and leather protectors, or arc-rated gloves are required. PPE Category 4: The final PPE Category requires AR clothing with a minimum rating of 40 cal/cm^2: