I really cannot stress enough the need for this application to be reviewed by a real expert (and I do NOT consider myself one!).
Just for illustration, let me describe a few different systems I've seen systems that had engineering and AHJ approvals:
A manufacturer of pool equipment sprayed some items with epoxy; others were powder-coated. In neither case was it necessary for special wiring.
A body shop constructed a booth. Lights were outside the booth, shining in through windows. Fans were driven, by belts, by motors outside the ducting. Only the fan switches need to be "rated."
A manufacturer sprayed his products inside the plant. The paint- an older solvent-based enamel- was applied in an area open to the rest of the plant, with minimal curtain separation. The wall immediatley behind the spray area was continuously washed with flowing water (a "water wall"). I do not recall any special electrical equipment, or ventilation. The "water wall" was exceptionally efficient at capturing overspray and fumes.
With these examples in mind, it is quite possible that the spray area has a very limited "classified" zone.
There is no substitute for professional judgement.
