TSO Info Hub

A quick reference guide for the TSO community

TSO Role Guide

Key Safety Documents

Support & Tools


In an Emergency

This website is dynamic and will grow with your input and ideas. Please don't hesitate to share feedback with us on: hse-tso-webpage-feedback@cern.ch

Your role as TSO or DTSO

The Territorial Safety Officer (TSO) is an important Safety role at CERN. TSOs are appointed by Department Heads or Technical Coordinator of Large Experiments for buildings and premises under their responsibility. The TSO shall keep themselves and the DSO(s) or LEXGLIMOSes to whom they report informed regarding all aspects of Safety related to their allocated buildings and premises. The full TSO Mandate is defined in the General Safety Instruction GSI-SO-2.

The mandate, details of appointed TSOs, and other safety roles, can also be found in Roles.

The safety heirachy at CERN. The DG, directors, and department heads have direct responsibility for safety. Department heads give delegated authority to a DSO or LEXGLIMOS, who in turn appoint the TSO and specialist officers.


Key documents

We advise you to consult the HSE webpages and Safety related webpages of your Department/Large Experiment regularly.
You will find some key documents that you should familiarize yourself with below.


Host State Regulations

Host States' relevant laws and regulations apply on a territorial basis where CERN has not established Safety Rules. Contact your DSO/LEXGLIMOS or HSE in case of doubt.

Click to expand lists

+ Switzerland
+ Geneva Regulation
+ France

Standards in English, French or German published by SNV, IEC, SIA, Electrosuisse and ISO) can be accessed via CERN’s Scientific Information Service on SNV Connect.

  • Click on Login
  • Select "Microsoft 365" under "external login"
  • Connect with your CERN account

Support & Tools

As TSO you report to the DSO(s) or LEXGLIMOS(s) of the Department(s) or Large Experiments responsible for the building(s) or premises for which you have been appointed. The DSO(s)/LEXGLIMOS(s) are also your primary support. They can provide mentorship, specific information, and act as a partner in troubleshooting safety matters.

Below is a list of essential web tools for routine and special procedures.

CERN Service Portal

Create a ticket, find key contacts, knowledge base (safety and health) etc.
Phone 72201 for machine buildings.

GIS Portal

Find a building, room, or road. View key data including safety features, assembly points, key personnel locations, pictures, noise risk, chemicals, and much more.


Allows management of activities, VICs, alarms (IS37), lock-outs, fire permits, DIMR radiation risk assessments, dose planning etc.


CERN’s platform for controlling access to facilities, buildings etc.


Access to reports: safety inspections (buildings, electrical etc.), evacuation plans, L3 alarm acceptance reports etc. Enter the building number in MTF: the “Document” and “Operation” tabs give access to the reports.


Find the different safety roles at CERN including their mandates as well as other roles at CERN. Safety roles have been tidied up and now provides updated information.

Please take the time and do the tutorial to easier find what you need.

Incident Form

Any person involved in-, witnessing or who becomes otherwise aware of a safety incident shall fill in the incident form within 24 hours of the incident or becoming aware of the incident.

As TSO you should report any accident (including incidents with material - or environmental damage), near miss or hazardous situation in your building. The form allows monitoring and analysis of safety incidents to understand and improve safety at CERN.

Occupational Accident Form (EDH)

To protect members of personnel against financial consequences from occupational accidents, illness or incapacity for work.

The declaration must be created within 10 working days or 3 months if materially unable to meet the deadline.

Accidents when commuting, on duty travel, home leave etc. may also be occupational accidents. This is determined by HR on receipt of the form.


Management of chemicals. To be updated upon changes or minimum once per year.

SAILOR Resolver

For CERN personnel in charge of solving safety remarks for general safety (buildings) and electrical installations (being introduced in 2024).

SAILOR Safety Reporting

For CERN safety managers to access safety inspections for buildings, lifting equipment & electrical installations (resolver not implemented yet). View CERES statistics. Useful to TSOs for overview and filtering capability.


Used by HSE-RP to manage the radiological classification of any location at CERN. Useful for CERN personnel to consult the classification.

Consult the learning hub RP awareness training for further information.

HSE Webpages

Find out more about the HSE Unit and its respective groups ENV, FRS, OHS, RP, TS, Medical Service.

SCE – Request for road markup (Demande de balisage)

Fencing and signage. Traffic controller.


What goes where?


Safety courses which could be useful for you and for the occupants of your building(s) and premises. If you have not received appropriate training, speak to your DSO/LEXGLIMOS(s).

Learning Hub Safety Courses Basic mandatory Safety Courses  TSO Training
First Aid - Life Saving Actions First Aid - SST (Workplace first aider) Emergency Guide Training
Fire extinguisher training Waste Management  


In an Emergency

In case of emergency or incident call:

+41 22 76 74444

Never transport an injured person yourself

Trigger the evacuation alarm if required, and alert others, where it is safe to do so.

Outside emergency situations, if you wish to contact the CFRS please use the admin line: +41 22 767 4848.