Hey guys, customer put up a new garage, and had a service pit put in below grade so he can just walk under vehicles and change oil and maintenance stuff. He had another electrician wire the shop, ran a conduit to the service pit but now refuses to wire lights in the pit. He's claiming it needs to be explosion proof and he won't take the liability of it. I'm having a hard time finding a code that validates his stance on the subject. My first thought was just feed it with a GFCI breaker and use vapor-proof lights. Only thing I know of in the code for explosion proof is the 500 hazardous locations, gas-dust-fibers. 511.8 for commercial garages does talk about underground wiring below hazardous location, but there's no gasoline or ignitable fuels being stored in this building. Thoughts?