Ingress Protection - IP Ratings

Liquid and/or solid particle ingress into electrical equipment can be harmful to equipment and operators of equipment. Therefore when buying electrical equipment it can be important to know what degree of "ingress protection" the item offers. The classification system utilizes the letters "IP" ("Ingress Protection") followed by two or three digits.

Ingress Protection - First Digit

The first digit of the IP code indicates the degree of ingress protection against solid foreign bodies.

Digit Ingress Protection
0 No special protection
1 Protection from a large part of the body such as a hand (but no protection from deliberate access); from solid objects greater than 50mm in diameter.
2 Protection against fingers or other object not greater than 80mm in length and 12mm in diameter.
3 Protection from entry by tools, wires, etc., with a diameter of thickness greater than 1.0mm.
4 Protection from entry by solid objects with a diameter or thickness greater than 1.0mm
5 Protection from the amount of dust that would interfere with the operation of the equipment.
6 Dust tight.

Ingress Protection - Second Digit

The second digit indicates the degree of ingress protection against the harmful entry of moisture.

Digit Ingress Protection
0 No special protection
1 Protection from dripping water.
2 Protection from vertically dripping water.
3 Protection from sprayed water.
4 Protection from splashed water
5 Protection from water projected from a nozzle
6 Protection against heavy seas, or powerful jets of water
7 Protection against immersion.
8 Protection against complete, continuous submersion in water.

An "X" is used for one of the digits if there is only one class of protection specified (e.g. IPX4 which refers to water ingress only).

Bathroom Electrical Equipment, IP Ratings and Zones

The requirement for electrical equipment used in bathrooms to have an appropriate degree of ingress protection is set out in the Building Regulations Part P (and British Standard BS7671:2008). These requirements divide the bathroom into zones as indicated as follows:

Zone 0 is inside the bath or shower itself. Any fitting used in this zone must be low voltage (max 12v) and be rated at least IP67 (which is protected agains immersion up to one metre).

Zone 1 is the area above the bath to a height of 2.25m from the floor. In this zone a minimum rating of IP44 is required.

Zone 2 is an area stretching 0.6m outside the perimeter of the bath and to a height of 2.25m from the floor. In this zone an IP rating of at least IP44 is required. In addition it is good practice to consider the area around a wash basin, within a 60cm radius of any tap to be considered as zone 2.

Outside Zone is anywhere outside Zones 0,1 and 2 (subject to specific limits) and where no water jets are likely to be used. No specific IP rating is required.

Note that the information provided here is intended to indicate the likely suitability of equipment. To avoid any risk of an unsafe installation you should always use a qualified electrician who is

  1. Familar with the requirements of the relevant regulations and standards
  2. Competent to interpret the above requirements in a given situation and
  3. Competent to carry out the work.