What NEMA or IP rating is a specific product?
Is a product protected against water and access by foreign objects?
The Degrees Of Protection document details both the IP rating and NEMA Enclosure charts.
The IP rating is made up of 2 digits, the first is the level of protection to foreign objects, the second is the level of protection to water.
If a product does not specify any rating for water ingress in it's datasheet then the the second digit will be 0.
The first digit relates to the size of a foreign object that can be inserted into the product.
Typically many Buildings products will not allow the insertion of a finger (12.5mm approx' 1/2") and offer no water protection, so they would be rated as IP20,
however it would be IP10 should they have holes of up to 50mm (approx' 2").