Abstract: A portable electric lamp suitable for use in hazardous locations has the fixture purged with breathable air a predetermined time before power is coupled to energize the lamps. The fixture is continuously purged during operation. If the internal pressure falls below a predetermined minimum level, or exceeds a predetermined maximum during operation, power to the lamps is shut off, and the complete start cycle, including the time delay, must be undertaken before the lamps can be re-started. All leads and components are either potted or operated at an intrinsically safe power level.