The IP (Ingress Protection) rating of a bulb or fitting determines the level of protection against dust and water. The first digit of the rating determines the dust resistance and the second digit refers to the water resistance.
IP20 - ‘2’ is not very dust resistant
- ‘0’ not protected from water at all
IP64 - ‘6’ is completely dust protected
- ‘4’ is protected from splashes of water
IP65 - ‘6’ is completely dust protected
- ‘5’ is protected from some water pressure
IP67 - ‘6’ is completely dust protected
- ‘7’ protected from immersion of up to 1m
IP ratings are especially important for bathrooms and outdoor lights as you need to make sure the fittings are waterproof, IP65s are recommended for outdoor lights and bathrooms lights as they are dust and water resistant.