New Page 4
The IP Code (or International Protection Rating[1], sometimes also interpreted as Ingress Protection Rating) consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures.[2] The standard aims to provide users more detailed information than vague marketing terms such as waterproof. The rating is also known as index protection.

The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. Where there is no protection rating with regard to one of the criteria, the digit is replaced with the letter X.

For example, an electrical socket rated IP22 is protected against insertion of fingers and will not be damaged or become unsafe during a specified test in which it is exposed to vertically or nearly vertically dripping water. IP22 or IP2X are typical minimum requirements for the design of electrical accessories for indoor use.

 First digit

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 Object size protected against Effective against
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, screws, 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; complete protection against contact
6 dust tight No ingress of dust; complete protection against contact

 Second digit

Protection of the equipment inside the enclosure against harmful ingress of water.

Level Protected against Details
0 not protected
1 dripping water Dripping water (vertically falling drops) shall have no harmful effect.
2 dripping water when tilted up to 15° Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position.
3 spraying water Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect.
4 splashing water Water splashing against the enclosure from any direction shall have no harmful effect.
5 water jets Water projected by a nozzle against enclosure from any direction shall have no harmful effects.
6 powerful water jets Water projected in powerful jets against the enclosure from any direction shall have no harmful effects.
7 immersion up to 1 m 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 beyond 1 m The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer.
NOTE: Normally, this will mean that the equipment is hermetically sealed. However, with certain types of equipment, it can mean that water can enter but only in such a manner that produces no harmful effects.

 Additional letters

The standard defines additional letters that can be appended to classify only the level of protection against access to hazardous parts by persons:

Level Protected against access to hazardous parts with
A back of hand
B finger
C tool
D wire

Further letters can be appended to provide additional information related to the protection of the device:

Letter Meaning
H high voltage device
M device moving during water test
S device standing still during water test
W weather conditions

Mechanical impact resistance

An additional number has sometimes been used to specify the resistance of equipment to mechanical impact. This mechanical impact is identified by the energy needed to qualify a specified resistance level, which is measured in joules (J). This has now been superseded by the separate IK number specified in EN 50102.

Although dropped from the 3rd edition of IEC 60529 onwards, and not present in the EN version, older enclosure specifications will sometimes be seen with an optional third IP digit denoting impact resistance. Newer products are likely to be given an IK rating instead. However there is not an exact correspondence of values between the old and new standards.

OLD IP Level Impact energy Equivalent drop mass and height
1 0.225 J 150 g dropped from 15 cm
2 0.375 J 250 g dropped from 15 cm
3 0.5 J 250 g dropped from 20 cm
5 2 J 500 g dropped from 40 cm
7 6 J 1.5 kg dropped from 40 cm
9 20.0 J 5.0 kg dropped from 40 cm
Equivalent impact
00 unprotected no test
01 0.150 drop of 200 gram object from 7.5 cm height
02 0.200 drop of 200 gram object from 10 cm height
03 0.350 drop of 200 gram object from 17.5 cm height
04 0.500 drop of 200 gram object from 25 cm height
05 0.700 drop of 200 gram object from 35 cm height
06 1.00 drop of 500 gram object from 20 cm height
07 2.00 drop of 500 gram object from 40 cm height
08 5.00 drop of 1.7 kg object from 29.5 cm height
09 10.0 drop of 5 kg object from 20 cm height
10 20.0 drop of 5 kg object from 40 cm height


  1. ^ IEC 60529(ed2.1), clause 4.1
  2. ^ IEC 60529: Degrees of protection provided by enclosures (IP Code). International Electrotechnical Commission, Geneva.
  3. ^ DIN 40050-9: Straßenfahrzeuge; IP-Schutzarten; Schutz gegen Fremdkörper, Wasser und Berühren; Elektrische Ausrüstung [Road vehicles; degrees of protection (IP-code); protection against foreign objects, water and impact; electrical equipment]. May 1993. (an English translation of the German original is available from DIN)
  4. ^

North American ingress-protection rating systems are defined in NEMA 250, UL 50, UL 508, and CSA C22.2 No. 94.