The IP (Ingress Protection) rating system provides a means of classifying the degrees of protection from foreign bodies and liquids afforded by electrical equipment and enclosures. The degrees of protection against the ingress of foreign bodies and liquids are indicated by the first two numerals as detailed in the table below. For example, IP66 rating provides total protection against the ingress of dust and can withstand powerful water jets.
| 1st | Description | 2nd | Description |
| 0 | No Protection | 0 | No Protection |
| 1 | Protected against ingress of objects => 50mm in diameter. | 1 | Protected against vertically falling drops of water. |
| 2 | Protected against ingress of objects => 12.5mm in diameter. | 2 | Protected against vertically fallings drops of water, when enclosure tilted up to 15 degrees. |
| 3 | Protected against ingress of objects => 2.5mm in diameter. | 3 | Protected against spraying water. |
| 4 | Protected against ingress of objects => 1mm in diameter. | 4 | Protected against splashing water. |
| 5 | Dust Protected | 5 | Protected against water jets. |
| 6 | Dust Tight | 6 | Protected against powerful water jets. |
| 7 | Protected against the effects of temporary immersion in water. | ||
| 8 | Protected against the effects of continous immersion in water. | ||