IP – ingress protection

Many applications place increased demands on electrical and electronic devices the moment they are to be used under more difficult ambient conditions. For this reason, many components are more or less well protected against dust and/or water. To be able to detect the type and the degree of protection at a glance, the so-called IP protection classes (International Protection Codes, IPC) were developed.

The classification in these protection classes is done on the basis of various German and international standards (DIN EN 60529, DIN 40 050- 9 or ISO 20653:2006-08; in each individual case, please inquire, since not all our suppliers work according to the same standards). But what is common to all the standards is the coding. Two code digits are always appended to the letters IP. These digits indicate the degree of protection that an housing offers with regard to foreign bodies (first digit) and moisture or water (second digit). As a substitute, one of the two digits can be replaced by an X if there is no classification for that condition. In DIN 40 050-9, the letter K indicates the marking of the equipment of road vehicles.

First digit

The first digit of the IP code indicates the protection of the enclosure with regard to foreign bodies.

Protection vs. solid objects Protection vs. touch
0 No protection No protection
1 Protected against solid objects with a diameter of 50 mm or more Protected against access with the back of the hand
2 Protected against solid bodies with a diameter of 12.5 mm or more Protected against access with a finger
3 Protected against solid bodies with a diameter of 2.5 mm or more Protected against access with a tool
4 Protected against solid bodies with a diameter of 1.0 mm or more Protected against access with a wire
5(K) Protected against dust in damaging quantities Fully protected against contact
6(K) Dustproof Full protection against contact


Second digit

The second digit informs about the protection against moisture or water.

Protection vs. water
0 No protection
1 Protection against vertically falling dripping water
2 Protection against falling dripping water when the enclosure is tilted up to 15°
3 Protection against falling spray up to 60° from vertical
4(K) Protection against splashing water from all sides/.
Protection against splashing water on all sides with increased pressure
5 Protection against water jets (nozzle) from any angle
6(K) Protection against strong jets of water/.
Protection against strong jets of water under increased pressure, specific for road vehicles
7 Protection against temporary immersion
8 Protection against permanent submersion
9(K) Protection against water during high pressure/steam jet cleaning, specific for road vehicles


Double indications

Enclosures of components which are only marked with the second code number 7 or 8 (temporary or permanent immersion) are classified as unsuitable against water jets (second code number 5 or 6) and do not have to fulfil this requirement. As a rule, a double designation is given in such cases.

Jet water Submersion Label
5 7 IPX5/IPX7
6 7 IPX6/IPX7
5 8 IPX5/IPX8
6 8 IPX6/IPX8
7 IPX7
8 IPX8


Note: The protection type classified as IP is not identical to the electrical protection class. Whereas IP protection classes define the degree of protection of the housing against contact, foreign body penetration and water, the electrical protection classes determine the measures against hazardous live voltages on parts of operating equipment that are not live under normal operation.

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