Emergency lighting: how often it is tested and how long it must last

Emergency lighting is equipment whose failure only shows at the moment it matters. That is why it is not checked by an occasional look but on a fixed schedule set by CSN EN 1838 and CSN EN 50172.

Three different tests, three different intervals

The most common misunderstanding is that emergency lighting has one annual inspection. In fact there are three distinct tasks that differ in scope and in who carries them out.

• Daily: a check of the status indicators on the central power supply, where the system has one. It is a look at the signalling, not an intervention.
• Monthly: a function test. The system is switched to emergency mode and the luminaires are verified to actually light up, together with a physical check that they are clean and undamaged.
• Annually: a duration test for the full rated time. This is the only test that shows whether the batteries still last as long as they should.

Sixty minutes is the minimum, not the target

The standard requires luminaires to stay lit for at least sixty minutes during a mains failure. In practice that is the value the system is designed around, and the battery stops meeting it long before anything is visible on the luminaire. That is exactly why the annual duration test matters: a short function test only confirms that the light comes on, not that it lasts an hour.

In larger buildings the test is therefore scheduled for a time when it does not matter that the system is temporarily without full backup while the batteries recharge. Systems with automatic testing perform part of the tasks themselves and the device protocol is transferred into the logbook.

The logbook: without it nothing can be proven

The results of all checks and tests are recorded in the emergency lighting logbook. This is not a formality: in an insurance claim or an inspection, the logbook is the only evidence that the system was maintained. It should contain the date, the scope of the task, any faults found, how they were resolved and who carried the work out.

Responsibility sits with the operator or owner of the building, not the supplier of the luminaires. That is the same logic as with fire extinguisher inspections : you can buy the equipment anywhere, the duty to maintain it stays with you.

What is most often found

• A flat or degraded battery that lights the luminaire but does not last the full duration.
• A luminaire covered or built over after a layout change, so it no longer lights where it should.
• Missing or badly placed escape route signs.
• An empty logbook even though the tests were in fact carried out.
• An escape route changed by a refurbishment while the lighting stayed per the original design.

A one page summary

Emergency lighting is function-tested monthly and tested annually for its full rated duration, at least sixty minutes. Systems with a central supply add a daily check of the signalling. Everything goes into the logbook and responsibility sits with the building operator. The annual duration test is the only one that reveals batteries nearing the end of their life.

Sources: CSN EN 1838 (Lighting applications - Emergency lighting), CSN EN 50172 (Emergency escape lighting systems); position as of October 2026.