This table shows what each digit or part of the IP (International protection) code represents.

IP indication Solid particle protection Liquid ingress protection
IP Single numeral: 0–6 Single numeral: 0–9

 

First digit: Solid particle protection

The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects

Level sized Effective against Description
0 No protection against contact and ingress of objects
1 >50 mm Any large surface of the body, such as the back of a hand, but no protection against deliberate contact with a body part
2 >12.5 mm Fingers or similar objects
3 >2.5 mm Tools, thick wires, etc.
4 >1 mm Most wires, slender screws, large ants etc.
5 Dust protected Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment.
6 Dust tight No ingress of dust; complete protection against contact (dust tight). A vacuum must be applied. Test duration of up to 8 hours based on air flow.

 

Second digit: Liquid ingress protection

The second digit indicates the level of protection that the enclosure provides against harmful ingress of water.

Level Protection against Effective against
1 Dripping water Dripping water (vertically falling drops) shall have no harmful effect on the specimen when mounted in an upright position onto a turntable and rotated at 1 RPM.
2 Dripping water when tilted at 15° Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle of 15° from its normal position. A total of four positions are tested within two axes.
3 Spraying water Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with a counterbalanced shield.

Test a) is conducted for 5 minutes, then repeated with the specimen rotated horizontally by 90° for the second 5-minute test. Test b) is conducted (with shield in place) for 5 minutes minimum.

4 Splashing of water Water splashing against the enclosure from any direction shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with no shield.

Test a) is conducted for 10 minutes. Test b) is conducted (without shield) for 5 minutes minimum.

5 Water jets Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects.
6 Powerful water jets Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects.
7 Immersion, up to 1 m depth Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).
8 Immersion, 1 m or more depth The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects. The test depth and/or duration is expected to be greater than the requirements for IPx7, and other environmental effects may be added, such as temperature cycling before immersion.
9 Powerful high temperature water jets Protected against close-range high pressure, high temperature spray downs.

Smaller specimens rotate slowly on a turntable, from 4 specific angles. Larger specimens are mounted upright, no turntable required, and are tested freehand for at least 3 minutes at distance of 0.15–0.2 m.

There are specific requirements for the nozzle used for the testing.

This test is identified as IPx9 in IEC 60529.

For more details: Wikipedia