One of the important things about enclosures is their ability to stand up to the environment they're place in. Nema 4 enclosures are numbered as '4' in a sliding scale because they have a substantial ability to be able to ward of chemical and physical attacks.
If you were to put an enclosure of this type in a regular household it would be put to waste, purely because it's built to withstand more than a basketball accidentally hitting it. They're designed for industrial of food processing facilities where they'll be taking serious chemical / physical attacks.
A good example would be a food processing center which has to be cleaned down at the end of every day. After the work is done all the surfaces are cleaned with chemicals that are corrosive if touched against regular steel enclosures. However a Nema 4 can withstand most chemical attacks for long periods of time whereas others would eventually sustain damage. They can also survive against physical attacks; I'm not talking about someone with an ax because they would eventually get in. But I am talking about constant freezing and thawing or perhaps high pressure steam / water being shot against it.
Nema 4 enclosures are one of the more durable and sustainable types of enclosures that you can definitely rely upon. Whether you work in an industrial facility or not you can be sure that your electrical enclosure is going to stand the test of time and the test of whatever you can throw at. They're definitely a great investment if you have a house of facility where the enclosure will sustain any kind of continuous damage. This generally means any sort of chemical solution that has low to mild corrosive properties, but when considering chemicals such as concentrated sulfuric acid.