The IP Code, or Ingress Protection Code is defined in IEC standard 60529 which classifies and rates the degree of protection provided by mechanical casings and electrical enclosures against intrusion, dust, accidental contact, and water.
The standard aims to provide users more detailed information than vague marketing terms such as waterproof. For example, a cellular phone rated at IP68 is "dust resistant" and can be "immersed in 1.5 meters 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 IP2X are typical minimum requirements for the design of electrical accessories for indoor use.
A complete description of the IP ratings and associated tests is found in IEC Publication 529. Although these ratings were initially developed as a way to classify enclosures, they now provide engineers with a convenient, practical way to compare levels of sealing. This standard describes a system for classifying the degrees of protection provided by the enclosures of electrical equipment. The adoption of this classification system promotes uniformity in methods of describing the protection provided by the enclosure and in the tests to prove the various degrees of protection.
Refer to the chart below for the ratings of relative protection of electrical enclosures:
The IP rating normally has two (but may have three) numbers:
- Protection from solid objects or materials
- Protection from liquids (water)
- Protection against mechanical impacts (commonly omitted, the third number is not a part of IEC 60529)