What are specialized Cables for explosion proof wiring?

Cables usually aren't the problem for explosion proof electrics and electronics. Switches, (motor/generator)brushes, breakers and relays are a (much) bigger issue. Followed by things using, or emitting electro-magnetic radiation. I assume, if you want to be thorough, one could use cables with a higher insulation/shielding rating for further protection in an explosion-prone environment.