It may be necessary to temporarily disable a fire/gas detection system to prevent it from being triggered accidentally, such as when hot work is being conducted. However, this implies taking compensatory measures, in particular monitoring. Safety Instruction 37 describes how to submit a disabling request using the IMPACT application: https://impact.cern.ch/.

The Fire and Rescue Service is responsible for training emergency guides, in collaboration with the TSO/DSO/LEXGLIMOS/EXSO of the department or large/medium/small experiment.

The Fire and Rescue Service is responsible for evacuation drills, in collaboration with the DSO/LEXGLIMOS/EXSO of the department or experiment.

No, none of CERN’s buildings are classified as an Établissement Recevant du Public (ERP) (public access building) under French law. However, CERN implements specific rules for the design and use of its buildings that meet equivalent requirements under French and Swiss law with regard to fire, electricity, evacuation, etc.

Given the calorific heat value of archives, the use of archive boxes made of non-combustible materials (e.g. metal) or fireproof materials is strongly recommended. Please refer to Safety Instruction 41.

The fire reaction requirements of construction materials and decorations used inside or outside buildings are defined by the regulations of the Host State concerned. AEAI standards 12-15, 13-15, 14-15, 15-15 are the main references for Switzerland and the Code du travail is the main reference for France. Additional requirements concerning the use of plastics and other non-metallic materials at CERN – which are particularly relevant in the experimental and underground areas – are set out in CERN Safety Instruction 41. Where sandwich panels are used indoors (e.g. in the work cabins of large halls), Safety Note 29 also applies.

Cables used at CERN must comply with the fire reaction requirements of Specific Safety Instruction SSI-FS-2-1. The requirements are as follows:

• High-risk areas: CPR class Cca, s2, d1, a2.
• Low-risk areas: CPR class Cca, s2, d1, a2.

These classes must be declared in a performance and compliance document or a test report. Alternative tests are accepted in cases where cables with CPR (Construction Products Regulation) certification are not available:

• Cables with specific technical characteristics (external diameter, bending radius, raw materials) where no CPR equivalent is available on the market,
• Fibre optic microconduit cables,
• Connection leads,
• Autonomous short-distance cables.

The notions of high and low risk for an installation are explained in table 1 (page 6) of Safety Instruction SSI-FS-2-1. If in doubt, contact hse-fset@cern.ch

The location of the assembly points is determined jointly by the CERN Fire and Rescue service and the DSOs/LEXGLIMOS/EXSOs of the department or large/medium/small experiment.

Information on emergency evacuations can be found in the Fire Safety section of the HSE website and in the “EVACUATION PROCEDURE AND PRINCIPLES FOR CERN SITES ON FRENCH TERRITORY”

A handrail is required if a staircase has more than three steps.

The CERN safety document on charging lithium-ion batteries is available on the EDMS 3234281 website. It was implemented on a one-year trial basis in March 2025. The fire protection measures governing lithium-ion batteries (use, storage, disposal, etc.) are as set out in the Swiss AEAI standard 2005-15 “Guide de protection incendie concernant les batteries lithium-ion” (Fire safety guide for lithium-ion batteries).

The maximum standing capacity in the Pas Perdus area (500/1) depends on the number of people present in Rooms A, B, C and D and in the Council Chamber. Relevant information is available in document EDMS 2804093.

After the fire brigade has left the site of an incident, you must:

• inform your management and your DSO/LEXGLIMOS/EXSO, if this has not already been done
• inform CERN’s insurance service so that the damage can be assessed and it can be established whether or not the cost of decontamination and repair work will be covered
• file an incident declaration report in EDH.

No, the use of stoves/heating plates is strictly forbidden in unauthorised areas such as offices in order to avoid accidents.

The requirements for installing fire-fighting equipment boxes can be found in the SRF form (EDMS 2682509). Isolated staircases and buildings with a fire safety control system are not concerned.

EDMS memo 1806075 clarifies the ownership of the various smoke-extraction systems at CERN and the associated maintenance responsibilities. NB: The services concerned are the EN-AA and SCE-SAM groups. You can contact these groups for assistance, keeping hse-fset (hse-fset@cern.ch) in the loop.

In the interests of protecting a building’s occupants, fire detection systems must be installed in accordance with the requirements of the regulations of the Host State concerned (AEAI 20-15 for Switzerland, Code du travail for France) and with the additional requirements of CERN Code E, annex VI.

Additional requirements to protect the environment may also apply, based on the relevant provisions of the OPAM (Ordonnance sur la protection contre les accidents majeurs – ordinance on protection against major accidents– in Switzerland) or ICPE (Installations classées pour la protection de l’environnement – classified installations for environmental protection – in FR). Based on an assessment by the owner or user of the premises, additional fire detection systems may be installed to improve the protection of property or in the interests of business continuity.

The Host State regulations lay down the fire safety measures to be taken for the handling and storage of dangerous goods, depending on the quantity present or used.

AEAI standard 26-15 is the main reference for Switzerland, and CERN’s Code E lays down additional requirements (e.g. approval of design by the HSE unit, fire detection, etc.). The application of fire safety regulations is without prejudice to the application of chemical safety regulations.