IK Ratings Explained: Impact Resistance for Sports Halls, Car Parks and Industrial Sites

Most people specifying lighting for a demanding environment reach first for the IP rating, and rightly so: dust and water are the everyday enemies of a luminaire. But there is a second code that governs a different kind of survival. The IK rating, defined in BS EN 62262, describes how much mechanical impact an enclosure can absorb without damage — and in a sports hall, a multi-storey car park, a school corridor or a loading bay, it is often the rating that matters most.

What the code measures

IK ratings originally ran from IK00 (no protection) to IK10. Each step corresponds to a defined impact energy, delivered by a specified mass dropped from a specified height onto the enclosure. The scale is not linear: IK06 is 1 joule, IK07 is 2 joules, IK08 is 5 joules — a 1.7 kg mass dropped from just under 30 cm — and IK10 is 20 joules, equivalent to a 5 kg mass dropped from 40 cm. The test is applied to the exposed surfaces of the fitting; the relevant product standard — BS EN 60598-1 for luminaires — then defines what counts as a pass, which in practice means no exposed live parts, no loss of ingress protection and no loss of function.

A 2021 amendment to the standard added IK11, a 50-joule test using a 10 kg mass dropped from 50 cm, for the most punishing locations. Anything beyond that — "IK10+", "IK12" and similar — is a manufacturer's own extension, sometimes backed by a genuine higher-energy test and sometimes not; treat it as marketing unless the test method is stated.

IK is not IP, and the two are not linked

A fitting can be IP66 and IK04, or IP20 and IK10. The IP code concerns ingress of solids and water; the IK code concerns impact. A sealed floodlight with a thin glass front may keep water out perfectly well and shatter at the first stray football. Conversely, a robust polycarbonate bulkhead may laugh off a hammer and still let water in through an unrated cable gland. Specify both, according to what the location actually threatens.

Materials, and where the weak point is

The IK rating is mostly decided by the diffuser or lens, because that is the largest and most exposed surface. Polycarbonate is the usual choice for high IK: it is tough, resists shattering and can readily reach IK10, though it yellows over time unless UV-stabilised. Acrylic (PMMA) is clearer and holds its colour better but is brittle, and generally tops out around IK07 or IK08. Toughened glass sits in between and is favoured where chemical resistance or a premium appearance matters. The body, end caps, mounting clips and gear tray also count: a fitting rated IK10 on its diffuser but held up by two plastic clips is only as robust as the clips.

Sports halls: a separate test

Sports halls deserve a specific mention because impact resistance there is governed by a different, purpose-made test. Ball-impact testing to BS EN 13964 Annex D, or the German DIN 18032-3 it derives from, fires handballs at the fitting — 36 shots from three directions at around 60 km/h in the toughest class — to confirm that nothing detaches, breaks or falls. Ask for class 1A to BS EN 13964 or a DIN 18032-3 certificate; the lower 2A and 3A classes are much gentler tests. A luminaire for a sports hall should carry this ball-proof certification as well as, not instead of, an IK rating. IK tells you it survives a single heavy blow; the ball test tells you it survives a season.

Matching the rating to the location

• Car parks, undercrofts and loading bays: IK08 as a minimum, IK10 where vehicles, trolleys or pallets pass close. Wall and low-level bollard fittings take the most punishment.
• Schools, sports centres and public corridors: IK08 for ceiling fittings out of reach, IK10 for anything on a wall or within reach of a jumping teenager.
• Sports halls: ball-proof certification plus IK08 or better, with wire guards where the fitting is particularly exposed.
• Custodial, secure and mental-health settings: IK10 combined with tamper-resistant fixings and anti-ligature design, which are separate requirements again.
• Industrial and workshop bays: IK08 to IK10 depending on traffic, with attention to chemical resistance if the diffuser will be cleaned with solvents.
• Ordinary offices and retail ceilings: IK02 to IK04 is normal and perfectly adequate. Paying for IK10 above a reception desk buys nothing.

IP keeps the weather out. IK keeps the fitting in one piece. A location that threatens both needs both, and the datasheet should state both.

The cost of an under-specified fitting in a harsh location is rarely the fitting itself; it is the access equipment, the labour, the disruption and the safety risk of replacing it — repeatedly. A higher IK rating typically adds little to the price of a bulkhead or batten and can remove that cycle altogether. Read the rating, check what it applies to, and where balls are involved, ask for the certificate that mentions them.