Also known as Explosion Proof, Explosion Protected, Ex Proof, Ex Rated – used worldwide as simple ways to say, “Explosion resistance.” Sometimes you may also see ‘flame proof,’ though that term is a bit misleading. In practice, Ex means the product or equipment cannot be a source of ignition or, if it does explode, the explosion is confined and controlled within the equipment.
Think of this like car engines: controlled explosions are used to drive pistons. In normal civilian cars, these are controlled within reasonable levels (for reliability and safety). In racing cars, engines are tuned for maximum power, so you may see flames shooting out of exhaust pipes, and sometimes race engines literally explode.