Is Vapor Proof the Same as Explosion Proof?
Often times, industrial projects are conducted in rugged environments, such as mining sites, enclosed tanks (confined spaces) and tunnels. Lights used in these unforgiving locations must be properly protected to prevent premature failure during critical tasks.
Doubling down on safety in industrial facilities starts at choosing the right type of lamp that can withstand rough elements present in the work site. Vapor proof and explosion proof are two features operators frequently seek out to address flammable and harsh environments.
Below takes a closer look at how the two types of fixtures differ.
Starting with vapor proof, this type of fixture is designed to withstand harsh locations that frequently encounter extreme temperatures, humid conditions, dust and water. With this in mind, vapor proof lights feature waterproof construction, tight seals and durable enclosures. For protection from rough contact, the units can be housed in impact-resistant casings, as well as incorporate impact-resistant lenses. Vapor proof lamps with thick, glass lenses offer extra protection from moisture and water vapor.
The main reason vapor proof lights require sealed construction is due to the presence of water vapor. On a molecular level, water vapor is smaller than watery liquid. As a result, vapors can pass through tight spaces and openings that are not fully sealed or protected.
Explosion proof lights are designed for exposure against flammable substances in hazardous locations. Examples of combustible elements include: methane, propane, hydrogen, metallic dust, flour and etc. Non-sparking materials, such as copper-free aluminum, polycarbonate and impact-resistant plastic, are applied to prevent ignitions. Because explosion proof fixtures are used in rugged work sites, the units may also be waterproof and completely sealed (a common feature in explosion proof luminaries) to prevent failure.
Safety standards associated with vapor proof and explosion proof may vary, depending on how the fixtures will be used and the type of location the units will be installed in:
Certification/Rating Vapor Proof Explosion Proof
NEMA Yes Yes
Approved for Damp/Wet Locations Yes Yes*
Waterproof (IP) Yes Yes*
Explosion Proof (Class I, II, III) No Yes
It is important to highlight that vapor proof and explosion proof lights may share a handful of similar certifications and protective ratings. An explosion proof light must adhere to explosion proof classifications (Class I, II, III) but does not necessarily have to be approved for damp/wet locations or include a high waterproof IP rating. On the other hand, a vapor proof lamp does not have to comply with explosion proof standards, but must be waterproof and approved for damp/wet locations.
NEMA protection is common in both types of industrial lighting systems. Because NEMA ratings also cover protection from water and can be cross-referenced with IP ratings, vapor proof fixtures can be protected by NEMA-rated enclosures. Explosion proof lights may also incorporate NEMA-rated housings, as this type of certification ensures protection from elements that can be combustible, such as dust.
Vapor Proof Lights: Car wash, subways, tunnels, walk-in freezers, food processing plants, wet locations, spray/wash-down areas, marine sites, shipyards, docks, construction sites, garages and etc.
Explosion Proof Lights: Hazardous locations, paint spray booths, mining sites, grain storage, confined spaces, ammunition factories, paper mills, cotton processing, petrochemical plants, automotive facilities, gasoline stations and more.