Regular lighting fixtures
do not resist moisture from vapor, but vapor proof lighting can. A vapor-proof fixture is available in different IP ratings such as IP65, IP66, and IP66. For IP65 rated vapor proof lights, it can withstand water from a 0.25" nozzle. IP66, on the other hand, can withstand water jets from 0.50" nozzle. Lastly. IP67, vapor proof's enclosure doesn't allow water to enter even submerged for 30 minutes at 1-meter depth.
Vapor-proof fixtures may share the same rating as waterproof equipment or tools, it doesn't mean that it can also resist water. It can only block moisture from vapor. Vapor proof fixtures are available in diecast housings, giving ultimate moisture protection for the lamp socket and the wiring. They are often used in areas such as subways, sports facilities, automotive repair shops, and construction sites