Understanding IP Ratings to BS EN 60529

When specifying electrical equipment—especially in demanding environments like leisure centres, swimming pools, chemical plants, and commercial kitchens—understanding the Ingress Protection (IP) rating is critical for ensuring compliance with BS 7671 (The IET Wiring Regulations). The IP code classifies and rates the degree of protection provided by mechanical casings and electrical enclosures against intrusion from solid objects, dust, accidental contact, and water.

How to Read an IP Code

An IP code consists of the letters “IP” followed by two digits. Each digit signifies a specific level of testing and protection:

• The First Digit (0-6): Indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects (from hands and tools to microscopic dust).
• The Second Digit (0-9): Indicates the level of protection against harmful ingress of water. The testing scales from light vertical condensation up to high-pressure, high-temperature jet washdowns.

Specification in Wet Areas & Bathrooms (Section 701)

BS 7671 strictly defines specific “Zones” in locations containing a bath or shower, with minimum IP requirements for each to prevent electrical shock:

• Zone 0 (Inside the bath or shower tray): Equipment must be strictly low voltage (SELV max 12 V) and rated to at least IPX7 (protection against immersion).
• Zone 1 (Directly above the bath or shower to 2.25 m): Equipment must be rated to a minimum of IPX4. However, if the area is likely to be subjected to water jets for cleaning purposes (such as in communal leisure centres), the minimum requirement increases to IPX5.
• Zone 2 (0.6 m outside Zone 1): Requires a minimum of IPX4 (or IPX5 if water jets are used for cleaning).

Industrial & Hazardous Environments

For industrial specifiers working in washdown areas, food preparation factories, or heavy engineering sites, specifying IP65 or IP66 is standard practice. These ratings ensure dust-tight operation while protecting the internal circuitry from high-powered hoses used during cleaning shifts.

For the most extreme environments, such as chemical processing plants or heavy vehicles, IP69K (or IPX9) provides absolute protection against high-temperature (up to 80 °C) and high-pressure washdowns.