05 July 2018
The IP rating, or International Protection Marking as it technically known is part of the IEC standard 60529. It is sometimes interpreted as Ingress Protection Marking, but its job is to classify and rate the degree of protection provided against intrusion (body parts such as hands and fingers), dust, accidental contact, and water by mechanical casings and electrical enclosures. It is published by the International Electrotechnical Commission (IEC). The equivalent British standard is EN 60529.
The standard aims to provide users more detailed information than vague marketing terms such as waterproof which can vary wildly. The digits (characteristic numerals) indicate conformity with the conditions summarised in the tables below. Where there is no data available to specify a protection rating with regard to one of the criteria, the digit is replaced with the letter X. The digit 0 is used where no protection is provided.
A rating of X for one or more of the protection criteria can be erroneously misinterpreted as “no protection”. To illustrate, a piece of electronic equipment rated IPX7 will almost certainly demonstrate a robust resistance to the ingress of particles, even though a rating for ingress of solids hasn’t been formally assigned. Hence, an X designation shouldn’t be automatically misconstrued as a lack of protection.
As an example in a more familiar context; a mobile phone rated at IP58 is ‘dust resistant’ and can be ‘immersed in 1.5 metres of freshwater for up to 30 minutes’.
Similarly, 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 2X are typical minimum requirements for the design of electrical accessories for indoor use.
The ratings for water ingress are not cumulative beyond IPX6. A device which is compliant with IPX7, covering immersion in water, need not be compliant with IPX5 or IPX6, covering exposure to water jets. A device which meets both tests is indicated by listing both tests separated by a slash, e.g. IPX5/IPX7.
It is important to note that there are no hyphens in a genuine IP code. IPX-8 (for example) is thus a false IP code.
By 2013, IEC/EN 60529 was updated to include the IPX9 water ingress test. This test appears to be identical to the IP69K test from DIN 40050-9. This page contains a mixture of IEC 60529 (also EN 60529) and other standards, such as DIN 40050-9. The original documents are available for purchase from their respective organisations and/or other licensed distributors, and have specific requirements which are important but cannot be fully reprinted due to copyright restrictions.
Breaking the code
An example IP rating is shown below using IP69K as a starting point as one of the most common you will find on an auto-electrical product from the Dun-Bri Group; in addition to what it stands for, how it will be displayed, and whether it is a mandatory or optional requirement of testing.
| Marking breakdown |
IP |
6 |
9 |
K |
| Single number (0-9) |
Single number (0-9) |
Single letter |
| Solid particle protection |
Water ingress protection |
Other protections |
| Mandatory requirement |
Mandatory requirement |
Optional |
Originally, there was a third number for mechanical impact resistance, but this is no longer used. Continue reading this article for detailed information as to the level of protection represented by the numbers used – remembering that the higher the number, the better the protection.
First digit summary
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 number |
Protection against |
Effective against |
Details |
| 0 |
None |
– |
– |
| 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. |
Test duration: 10 minutes
Water equivalent to 1 mm rainfall per minute |
| 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. |
Test duration: 2.5 minutes for every direction of tilt (10 minutes
total)Water equivalent to 3 mm rainfall per minute |
| 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 tilted 90° for the second 5-minute test. Test b) is conducted (with shield in place) for 5 minutes minimum. |
For a Spray Nozzle:
Test duration: 1 minute per square meter for at least 5 minutes
Water volume: 10 litres per minute
Pressure: 50–150 kPa
For an oscillating tube:
Test duration: 10 minutes
Water Volume: 0.07 l/min per hole |
| 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. |
Oscillating tube: Test duration: 10 minutes, or spray nozzle (same
as IPX3 spray nozzle with the shield removed) |
| 5 |
Water jets |
Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects. |
Test duration: 1 minute per square meter for at least 3 minutes
Water volume: 12.5 litres per minute
Pressure: 30 kPa at distance of 3 m |
| 6 |
Powerful water jets |
Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. |
Test duration: 1 minute per square meter for at least 3 minutes
Water volume: 100 litres per minute
Pressure: 100 kPa at distance of 3 m |
| 6K |
Powerful water jets with increased pressure |
Water projected in powerful jets (6.3 mm nozzle) against the enclosure from any direction, under elevated pressure, shall have no harmful effects. Found in DIN 40050, and not IEC 60529. |
Test duration: at least 3 minutes
Water volume: 75 litres per minute
Pressure: 1000 kPa at distance of 3 m |
| 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). |
Test duration: 30 minutes – ref IEC 60529, table 8.
Tested with the lowest point of the enclosure 1000 mm below the
surface of the water, or the highest point 150 mm below the surface,
whichever is deeper. |
| 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. |
Test duration: Agreement with Manufacturer
Depth specified by manufacturer, generally up to 3 m |
| 9K |
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. |
Test duration: 30 seconds in each of 4 angles (2 minutes total)
Water volume: 14–16 litres per minute
Pressure: 8–10 MPa (80–100 bar) at distance of 0.10–0.15 m
Water temperature: 80 °C |
More information on IP69K
German standard DIN 40050-9 extended the older IEC 60529 rating system with an IP69K rating for high-pressure, high-temperature wash-down applications. Such enclosures must not only be dust-tight (IP6X), but it must also be able to withstand high-pressure and steam cleaning. By 2013 IEC 60529 added level 9 water ingress testing, with IPx9 being essentially the same spray test as IP69K, also adding a drawing of a fixture to verify the water pressure.
The test specifies a spray nozzle that is fed with 80 °C water at 8–10 MPa (80–100 bar) and a flow rate of 14–16 L/min. The nozzle is held 10–15 cm from the tested device at angles of 0°, 30°, 60° and 90° for 30 seconds each. The test device sits on a turntable that rotates once every 12 seconds (5 rpm). The IPx9 specification in IEC 60529 has details for testing larger specimens that will not fit on a turntable test fixture (see table above).
The IP69K test specification was initially developed for road vehicles, especially those that need regular intensive cleaning (dump trucks, cement mixers, etc.), but it also finds use in other areas (for example, the food industry and car wash centres).
Finding more information on IP ratings
We have produced a fairly extensive guide, but you can find more information from the DIN and ISO standards – available to purchase from their organisations. For help with a specific product, please contact us by calling us on 01763 274185, emailing us at sales@dun-bri.com or by visiting your local branch…