Explosion-proof exit signs, emergency lights, and combo units are sealed, spark-containing fixtures engineered so any internal arc, heat, or flame is contained within the housing, preventing ignition of surrounding gases, vapors, dusts, or fibers. Additionally, these explosion proof products also meet the temperature requirements of the specific application in which they are to be installed, per Nationa Electric Code (NEC®) standards. Each component is labeled on its nameplate with the distinct. Horizontal exits are a type of exit that protect occupants from the effects of fire without requiring vertical travel, such as within a stairwell. In some cases, they don't even require occupants to exit a building. Exit Access: leads to an exit (corridors, aisles, rooms, ramps)., enclosed stair, exit passageway). The minimum number. Use the interactive Hazard Zone Configurator to match your Class/Division/Group, T-Code, ambient, and exposure.