NICEIC Domestic InstallerGuides
IP ratings: what the numbers mean
Reading the two digits on a fitting before you put it in a bathroom or garden.
Published · Updated · By 2K Electrical Services
Every light fitting, socket, fan or enclosure carries an IP rating (Ingress Protection, from BS EN 60529). The two digits tell you how well the casing keeps out solids and water. An X in place of a digit means the product has not been tested for that type of ingress, not that it has no protection.
First digit: solid objects and dust
| Digit | Protects against |
|---|---|
| 0 | Nothing |
| 1 | Objects larger than 50 mm, such as the back of a hand |
| 2 | Objects larger than 12.5 mm, such as a finger |
| 3 | Objects larger than 2.5 mm, such as tools and thick wires |
| 4 | Objects larger than 1 mm, such as thin wires and screws |
| 5 | Dust that could interfere with the equipment |
| 6 | Completely dust-tight |
Second digit: water
| Digit | Protects against |
|---|---|
| 0 | Nothing |
| 1 | Dripping water falling vertically |
| 2 | Dripping water when the enclosure is tilted up to 15° |
| 3 | Spraying water at up to 60° from vertical |
| 4 | Splashing water from any direction |
| 5 | Low-pressure water jets from any direction |
| 6 | Powerful water jets and heavy seas |
| 7 | Temporary immersion up to 1 m |
| 8 | Continuous immersion beyond 1 m, as specified by the manufacturer |
Where the common ratings fit
- IP20 is the typical indoor rating for a switch or downlight in a dry room.
- IPX4 or better is required in bathroom zones 1 and 2 (BS 7671 Section 701); choose IP44 as a minimum there, and IP65 directly over a shower if you want a margin.
- IPX5 is required where water jets are likely, for example in a wet room that is hosed down.
- IP65 to IP66 is the sensible choice for garden lights, outdoor sockets and external junction boxes.
- IP67 and IP68 are for pond lights, underground joints and anything that may sit in water.
Always check the manufacturer’s instructions as well as the rating: a fitting may be IP65 but still unsuitable for a particular zone or for mounting in a ceiling.
