As a Lighting Consultant I have to ensure that I specify light fittings in wet areas such as bathrooms, swimming pools or outside that are watertight enough to particular levels depending on how close to the source of water they are. The level of water tightness is expressed with an IP (Ingress Protection) rating which consists of two numbers – the first relates to the level of protection from solid objects of materials, such as dust particles, and the second to the level of protection from water. So, it is only the second number that is of interest in these cases as it expresses the level of water tightness. The IP ratings for water-tightness are:
| IP No. | Water Protection Provided by the Light Fitting |
| 0 | No special protection |
| 1 | Protection against condensation |
| 2 | Protection against water droplets deflected up to 15° from vertical |
| 3 | Protection against spray up to 60° from vertical |
| 4 | Protected against water spray from all directions |
| 5 | Protection against low pressure water jets from all directions |
| 6 | Protection against high pressure water jets and waves |
| 7 | Protected against temporary immersion |
| 8 | Protected against the prolonged effects of submersion under pressure. The maximum submersion depth also needs to be specified, e.g. IP6X8 to 1 bar pressure = to 9m water depth |
