Explosion Proof Distribution Box & Electrical Enclosures are certified for Class I, Division 1 and Class II, Division 1. You need to check if the enclosure fits the danger level and protection type. For example, you might need Ex d for flameproof or Ex i for safe designs. The. Wall penetrations require double sealing with flameproof putty and compression glands: Fundamental Principle : Your safest distribution box is the one that's not in the hazardous area at all. Hot surfaces Flames, hot gases, hot particles Mechanically generated sparks Electrical equipment Stray electric currents, cathodic corrosion protection Static. This system for explosion proof ratings uses Classes, Divisions, Groups, and Temperature Codes (T-Codes) to describe the type of hazard in the area and how often it occurs. Class: The general type of hazard present. Group: The specific type of. Ex Industries (exindustries) is a global supplier of advanced hazardous area solutions, offering a wide portfolio of certified products including explosion proof electrical boxes, explosion proof junction boxes, explosion proof lighting, intrinsically safe barrier systems, explosion proof cables.