for illuminating an area of a structure which is prone to explosion due to dust or vapors in the atmosphere , a system includes fluorescent type lighting devices which are energized by radio frequency energy without any physical connection to the lighting devices . the lighting devices include sealed envelopes having fluorescent material on the inner wall surfaces , and containing a gas which responds to external radio frequency electromagnetic radiation to excite the fluorescent material and produce visible light . the lighting devices are mounted within the structure by insulating brackets and may be mounted within impact resistant protective enclosures . the lighting devices are energized by radiating devices of electromagnetic energy which are mounted adjacent to the several lighting devices within the explosion prone area , and which are supplied with radio frequency electromagnetic energy through appropriate means from a generating source remote from or outside of the explosion prone area . the radiating devices may be metal rod antennas supplied with energy through a coaxial cable conduit . to utilize higher frequency energy , the radiating devices may be resonant horns or radiating disks connected to waveguide conduit which transmits the energy into the explosion prone area . the transmission conduit and radiating devices may be suitably insulated with rugged unbreakable solid plastic , virtually eliminating the possibility of flame , spark or heat to trigger an explosion .