The explosion-proof rating of the floodlights used in power plants is usually EX-d or EX-e.
Because these ratings indicate that the floodlights are designed to contain any explosions within them, this is important in a power plant setting, as explosions could cause severe damage and injury. The EX-d rating indicates that the floodlight is designed to contain any explosions. In contrast, the EX-e rating suggests the floodlight is intended to prevent any outbreaks outside it.