Here are two pics showing hazardous-location (classified area) wiring done by someone who wasn't clear on the concept.
The first is of the entrance to a pre-fab, "engineered" booth for painting trucks. While the lights are technically outside the booth, and thus outside the 'zone', one light, as well as the controls are within 3 ft of the door, and thus within the zone (516.3B4)
I am so reassured to know that someone is out there, manufacturing these booths by the hundreds!
The second pic shows the disconnect for a propane distributor's pump. Fittings used reveal that EMT was run after the seal, then transitioned near the ground to PVC.
It is permitted to use PVC for the underground portion- but the transition is to be made two feet down, after the bend. EMT after the seal is, of course, not very "explosion- proof" at all
What bothers me most about these pics is that in both cases- one a manufacturer, and the other a utility-type company- there had to have been numerous "professionals" involved who should have known better.