Thanks for your responses.
Hazardous Area work is something that I try to keep right away from.
I have repaired the odd pump in the Fuel pumps here and that was as close as I wanted to get to that kind of thing.
I am the Maintenance Electrician, at a local Flour Mill and we have been changing over the last few years, all of the motors to Non-Sparking types (ExN), some of them were Slip-ring types for speed control, but Micro-drives put that fire out!.
Last guy didn't have a clue!.