IP classification - definitions for water- and dust-proofing

IP (International Protection) classification is used in Europe to define a casing's protection against dust and water, for example.

The code is made of several digits that represent protection against:
- first digit: solid particles
- second digit: liquids
- additional letter: other protections.

1. digit Protection level
0 No protection.
1 Any large surface, >50 mm (no deliberate contact).
2 Medium surfaces, diameter >12,5 mm.
3 Small surfaces, diameter >2,5 mm.
4 Very small surfaces, diameter >1 mm.
5 Dust protected, ingress not entirely prevented.
6 Dust tight.


2. digit Protection level
0 No protection.
1 Falling water equivalent to 3-5mm rainfall per minute for a duration of 10 minutes. Unit is placed in its normal operating position.
2 Falling water when tilted up to 15 degrees - Same as IPx1 but unit is tested in 4 fixed positions - tilted 15 degrees in each direction from normal operating position.
3 Protected against spraying water - Water spraying up to 60 degrees from vertical at 10 liters/min at a pressure of 80-100kN/m2 for 5 min.
4 Protected against splashing water - Same as IPx3 but water is sprayed at all angles.
5 Protected against water jets - Water projected at all angles through a 6.3mm nozzle at a flow rate of 12.5 liters/min at a pressure of 30kN/m2 for 3 minutes from a distance of 3 meters.
6 Protected against heavy seas - Water projected at all angles through a 12.5mm nozzle at a flow rate of 100 liters/min at a pressure of 100kN/m2 for 3 minutes from a distance of 3 meters.
7 Protected against water immersion - Immersion for 30 minutes at a depth of 1 meter.
8 Protected against water submersion - The equipment is suitable for continual submersion in water under conditions which are identified by the manufacturer.
9K Protected against close-range high pressure, high temperature spray downs. (DIN 40050-9, not part of IP classification)


For example:
- most Aquapac-bags are classified as IPx8, where the X stands for no testing against dust nor foreign surfaces and the 8 stands for protection against water submersion
- most Petzl headlamps are classified as IPx4, where the X stands for no testing against dust nor foreign surfaces and the 8 stands for protection against splashing water.