It is a standard from IEC 60529 (International Electrotechnical Commission).
Ingress Protection code (IP Code) – which defines an enclosure rating. The IP Code reflects the degree of protection as IP followed by 2 digit numbers.
The 1st digit ranges from 0 to 6, reflecting in degrees the level of protection against the solid particles.
The 2nd digit ranges from 0 to 9 and indicates the protection against the water ingress.
First digit – Solid protection level.
|1||Protection against solid objects > 50 mm, such as a hand|
|2||Protection against solid objects > 12.5 mm, such as a finger|
|3||Protection against solid objects > 2.5 mm, such as tools|
|4||Protection against solid objects > 1.0 mm, such as wire or small screws.|
|5||Dust resistant, limited protection from the ingress of dust, ingress of dust not sufficient to cause harm. 2 to 8 hours.|
|6||Dust-tight, total protection from the ingress of dust 2 to 8 hours.|
Second digit – Water protection level.
|1||Protection against vertically dripping water, some ingress permitted|
|2||Protection against dripping water with enclosure tilted up to a 15° angle|
|3||Protection against spraying water|
|4||Protection against splashing water.|
|5||Protection against jets of water directed at the enclosure.|
|6||Water or heavy seas, Protection against powerful jets shall not enter in harmful quantities.|
|7||Protection against effects of immersion in water up to 1 m for a period of 30 minutes.|
|8||Protection against effects of immersion in water up to 3 m for long periods.|
|9||Protection against high pressure and temperature water jet|
Equivalent IP ratings: