EN 50172:2024 is the current European standard for emergency escape lighting systems; in Germany it is published as DIN EN 50172 (VDE 0108-100):2024-10 and replaces both the 2005 edition and the national pre-standard DIN VDE V 0108-100-1:2018-12, with a transition period until 27 May 2027. The main changes concern testing, handover documentation and the logbook – most notably a new illuminance measurement every 5 years under section 7.4.5. Existing installations can usually continue to be operated to the requirements they were built to, but the applicable testing basis should be clearly defined and recorded.
What does EN 50172 cover?
EN 50172 is the standard for emergency lighting systems: it describes how safety lighting is designed, installed, handed over, operated and periodically tested. It does not decide whether a building needs emergency lighting – that follows from national workplace and building law, the building permit and the fire safety strategy. The lighting values themselves are set out in EN 1838.
For operators, EN 50172 is the standard that matters most day to day, because it sets the test intervals and documentation duties. How it fits together with the other rules is explained in Emergency lighting standards.
Which documents does the 2024 edition replace?
At European level, EN 50172:2024 replaces the 2004/2005 edition. Several countries have national documents alongside it. Example Germany: two documents were previously applied side by side.
| Document | Previous role | Status |
|---|---|---|
| DIN EN 50172 (VDE 0108-100):2005-01 | German edition of the European system standard | Replaced by the 2024-10 edition |
| DIN VDE V 0108-100-1:2018-12 | National pre-standard applied in addition, with extra German requirements | Replaced by the 2024-10 edition |
| DIN EN 50172 (VDE 0108-100):2024-10 | – | Current edition, basis for new designs |
With the 2024-10 edition, new installations in Germany once again have one governing system standard. Content from the former pre-standard is, however, still quoted in building permits, fire safety strategies and older documents and may continue to matter for a specific building. Other countries, such as the UK with BS 5266-1, keep their own national codes alongside EN 50172.
What has changed in substance?
The new edition mainly affects the phase after installation: testing, handover and documentation. The key points for operators:
Illuminance measurement every 5 years
Under section 7.4.5, the illuminance of the safety lighting is measured every 5 years. This checks whether the installation still achieves the EN 1838 values demonstrated at the design stage – after luminaire ageing, soiling, alterations or a change of use. The measurement report is kept with the logbook. Measurements are taken in emergency mode with a suitable lux meter, typically with the normal lighting switched off. The values that apply are covered in Emergency lighting illuminance.
Test intervals
For installations to the new standard, the framework is a monthly function test, an annual test over the full rated duration and the new 5-yearly measurement. Depending on the testing basis, central battery systems may also need a daily reading of their indicators. Example Germany: weekly function checks required under the former pre-standard may still apply to existing installations on a building-specific basis. All intervals in detail: Testing intervals.
Handover documentation
The requirements for the documents the installer hands over to the operator are more clearly defined. Typically these include drawings showing every luminaire and sign, the lighting calculation, the luminaire list, rated duration and operating mode, datasheets, records of the initial verification and the defined test intervals. The exact scope for your building should be agreed in the installation contract.
Logbook
The logbook requirements have also been revised. The report of the 5-yearly measurement now belongs in it, and it is good practice to record the testing basis and test intervals that apply to the installation.
What applies during the transition period?
Example Germany: until 27 May 2027, the previous documents – DIN EN 50172:2005-01 and DIN VDE V 0108-100-1:2018-12 – may still be applied. For new designs it makes sense to use the 2024 edition now, so that the installation does not document an outdated state shortly after handover. Transition arrangements in other countries depend on the national standards body.
Do existing installations have to be upgraded?
As a rule, no. Standards are generally not retrospective: an installation designed and accepted to the rules in force at the time may continue to be operated. Existing installations may therefore remain subject to the previous requirements, especially where the building permit, an inspection report or the fire safety strategy refers to them.
This protection has limits. It covers the installed state, not a lack of testing or maintenance. After major alterations, extensions, a change of use or an order from the authorities, the current standard may apply to the altered part or to the whole installation. Defects – such as a luminaire that no longer reaches its rated duration – must be remedied promptly regardless of the edition; in Germany, ASR A2.3 requires this without delay. Whether your installation should be modernised is discussed in Upgrading emergency lighting.
Practical tip: Many operators carry out the 5-yearly measurement voluntarily on existing installations too. It is the only test that shows whether enough light still reaches the escape route after alterations, new furniture or luminaire replacements.
What should operators do now?
- Define the testing basis: decide whether your installation is tested to EN 50172:2024 or, building-specifically, to previous requirements, and record this with the intervals in the logbook.
- Review your documents: check the building permit, fire safety strategy and inspection reports for references to national pre-standards or specific test intervals.
- Schedule the 5-year measurement: set a date, arrange the contractor and instrument, and add the report to the logbook.
- Update the luminaire list: every luminaire and sign clearly numbered, with type, operating mode and rated duration.
- Assign responsibilities: name who reads indicators and presses test buttons in-house, and which qualified electrician handles duration tests, measurements and repairs.
- Set up a defect process: a failed duration test is a defect; the reporting route, response time and interim measures should be agreed in advance.
- Specify new projects properly: for new builds and upgrades, require the 2024 edition and the scope of handover documentation in the contract.
What changes for the logbook?
The logbook remains the central evidence that the installation was tested and ready for use. Under the new edition it should contain at least: the installation's master data and handover documentation, the defined testing basis and intervals, the luminaire list, every test with a clear result, defects with action taken and re-test, maintenance and alterations, and the report of the 5-yearly measurement. What belongs in it and how long it is kept is explained in Emergency lighting logbook. A free logbook template is available under Downloads.
A digital logbook is generally acceptable if it is complete, traceable and protected against later changes. As part of its maintenance service, NOTLUX records every test digitally in an app, including the luminaire list and defect tracking.
This article is not legal advice. The requirements for your installation follow from the building permit, the fire safety strategy, national rules and the defined testing basis.
Frequently asked questions
When does EN 50172:2024 become mandatory?
The German edition was published in October 2024. In Germany, the previous documents may still be applied until 27 May 2027; after that, the 2024 edition is the basis for new installations. Other countries follow their national adoption and withdrawal dates.
Do I need to upgrade my existing emergency lighting now?
Usually not. Existing installations may continue to be operated to the requirements they were built to, unless the permit or the authorities require otherwise. Testing, maintenance and the remedy of defects remain mandatory.
Does the 5-year measurement apply to older installations?
It is required for installations to the new standard. For existing installations it depends on the defined testing basis. Either way, it is useful evidence that enough light still reaches the escape routes after alterations or luminaire replacements.
Are weekly tests still required under the new standard?
For installations to EN 50172:2024, the monthly function test and the annual duration test are the norm, with a daily indicator check for central systems depending on the testing basis. In Germany, weekly checks under the former pre-standard may still apply to existing installations on a building-specific basis.
What happens if a luminaire fails the annual duration test?
That is a defect. It is recorded in the logbook and must be remedied promptly and properly, with interim measures in place until then. In Germany, ASR A2.3 requires defects to be eliminated without delay.
Who may carry out the new illuminance measurement?
The measurement belongs with a qualified electrician or a specialist contractor with a suitable instrument. The operator's instructed staff may read indicators and press test buttons, but may not open luminaires or assess measurements.
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