IP is an abbreviation for 'Ingress Protection' and defined in the international product standards EN60529. IP Ratings are used to define the levels of seal effectiveness against intrusion from foreign bodies and moisture. An IP Rating takes the format of two letters "IP" and two numbers "44", the first number is protection rating against foreign bodies and the second is the protection against moisture.
IP44 - Protected against objects greater than 1mm in size and water splashing from any angle
IP56 - Protected against Dust particles and powerful water jets / Heavy Sea's
IP68 - Fully Protected against Dust particles and water submersion
When choosing a light fitting its important to understand the limitations of the fitting in relation to the levels of moisture and dust exposure. The minimum recommended IP rating for a light fitting placed outside or in a bathroom is IP44 however this depends on several factors. Have a look at the zoning image on the right to understand the IP requirements of your bathroom.
Note: Zones 1, 2 and 3 IP rating should be revalued to IP55 or greater in the presence of water jets or high splash risk
IP Ratings in your garden traditionally operate in the same manner with a minimum requirement of IP44 and a recommended requirement of IP65. For any light fixtures in close proximity to a water source it is recommended to use IP67 / IP68.