CERN — The European Laboratory for Particle Physics

The Guide should remind visitors of the following Safety Rules.


  • Safety of those workig at CERN or visiting the laboratory is our highest priority

  • The experimental area does contain a number of hazards that stem from operating the detector, e.g. gas systems, high voltage lines, magnetic fields and possible low levels of residual radioactivity

  • The magnet is currently off and will stay so during the visit, hence there are no particular restrictions


  • The magnet is currently on. For this reason persons with pacemakers, defibrillators, electronic medicine dispensers, hearing aids or metal implants are not allowed in the underground visit

  • There is no residual radioactivity in the Visit’s areas. If we would need to enter the Supervised area the levels are very low and we have dosimeters to monitor it

  • There are also always basic risks such as falls, trips and slips

  • In addition, many of the instruments, electronics, and other devices encountered in these areas are delicate and should only be handled by experts

- We therefore ask you to stay in the areas marked for visitor access and designated by your guide and not to touch any of the equipment

- Eating and drinking are strictly forbidden while underground

- Should an alarm occur please follow the instructions given by your guide who will conduct you to the surface using the lift