IP Rating Guide — Ingress Protection Explained for UK Electricians

IP stands for Ingress Protection (sometimes called International Protection). It is a classification system defined by BS EN 60529 (IEC 60529) that describes how well an electrical enclosure protects its contents against the intrusion of solid objects (dust, fingers, tools) and liquids (dripping water, sprays, jets, submersion).

Every piece of electrical equipment — from consumer units to outdoor luminaires, from socket outlets to junction boxes — has an IP rating that tells the installer what environments it can be safely used in. Selecting equipment with the wrong IP rating for the location is a common cause of equipment failure, water damage, and potential safety hazards.

The IP rating is written as "IP" followed by two digits. The first digit describes protection against solid objects (0 to 6). The second digit describes protection against liquids (0 to 9). A higher number means greater protection. For example, IP65 means the enclosure is completely dust-tight (6) and protected against water jets from any direction (5). This knowledge is fundamental when completing EICR inspections and verifying that installed equipment is appropriate for its location.

The first digit of the IP code indicates the level of protection against solid objects and body parts accessing hazardous internal components:

For electrical safety the key level is 2, finger protection. BS 7671 Regulation 416.2.1 requires live parts to be inside enclosures or behind barriers giving at least IPXXB or IP2X, with narrow exceptions such as openings needed while replacing lamps or fuses. Readily accessible top surfaces need IPXXD or IP4X (Regulation 416.2.2).

The second digit describes the degree of protection against water and other liquids. Each level includes all the protection of the levels below it (for example, IPX5 provides protection against water jets, which inherently includes protection against splashes and drips):

Note that IPX7 and IPX8 (immersion/submersion) are independent tests — an enclosure rated IPX7 is not necessarily rated IPX5 (jets) unless it is tested and rated for both. Some manufacturers specify dual ratings such as IP65/IP67 to confirm both jet and immersion protection. This is relevant when selecting outdoor lighting fixtures and external accessories.

The following IP ratings are the ones electricians encounter most frequently in UK installations:

• IP20 — protected against finger contact and objects larger than 12.5 mm. No water protection. Standard for indoor consumer units, distribution boards, and socket outlets in dry locations.
• IP44 — protected against objects larger than 1 mm and splashing water from any direction. Minimum for general outdoor use, and the minimum for zones 1 and 2 of a bathroom (Regulation 701.512.2). Common for outdoor socket outlets.
• IP55 — dust-protected and protected against water jets. Suitable for exposed outdoor locations and industrial environments. Common for external junction boxes and motor terminal boxes.
• IP65 — dust-tight and protected against water jets. Used for outdoor luminaires, floodlights, and equipment in wash-down areas. The standard rating for commercial LED battens in industrial settings.
• IP67 — dust-tight and protected against temporary immersion to 1 metre. Used for in-ground lighting, equipment in wet pits, and connectors exposed to flooding risk.
• IP68 — dust-tight and protected against continuous submersion. Used for swimming pool lighting, underwater equipment, and cable glands on submersible pumps.

Selecting the correct IP rating for each location is checked during EICR inspections. Equipment with too low an IP rating for its location is recorded as an observation, usually C2 (potentially dangerous) where water or dust could reach live parts, or C3 (improvement recommended) where it could not. Understanding observation codes helps interpret these findings correctly.

BS 7671 frequently references IP2X and IPXXB as minimum requirements for protection against direct contact with live parts. These two designations are related but not identical:

IP2X means solid objects of 12.5 mm and larger cannot enter, and the jointed test finger cannot reach live parts. The "2" is the first digit, referring to solid object protection. The "X" means the second digit (liquid protection) is not specified — it could be anything from 0 upwards.

IPXXB uses the additional letter "B" from BS EN 60529, which covers access only: the jointed test finger (12 mm diameter, 80 mm long) cannot reach live parts, even though the opening may be bigger than 12.5 mm. It is used where an enclosure has larger openings that are still finger-safe, such as the gaps around devices in a board.

Regulation 416.2.1 is why a board must have blanks in every spare way and why a missing blank is a standard EICR finding: the open way breaks the IPXXB enclosure. If an existing board does not meet IP2X/IPXXB, this is recorded as an observation during an EICR inspection.

Bathrooms have their own minimums under Regulation 701.512.2: IPX7 in zone 0, IPX4 in zones 1 and 2, and IPX5 where water jets are used for cleaning. The EIC certificate records the IP rating of equipment installed in special locations.