Have you found an old smoke detector while clearing a workshop, laboratory, storage area or installation? Before throwing it away, take a closer look. During cleanup activities, these detectors can easily be mistaken for obsolete equipment and discarded as general or electronic waste.

However, some older smoke detectors, particularly ionisation smoke detectors, contain a small radioactive source as part of their sensing mechanism. While these devices present little risk when intact, the radioactive source remains subject to CERN’s radiation protection regulations and must be managed accordingly. They must not be dismantled, disposed of or transferred without appropriate consideration of the radioactive source they may contain.

If you come across an old smoke detector that may contain a radioactive source, or if you know of one being stored or used at CERN, please inform the Radiation Protection (RP) Radioactive Sources team at service-rp-sources@cern.ch.

When in doubt, please contact the RP team before a detector goes in the bin: this helps ensure that these regulated sources remain properly tracked and managed.

Stop. Think. Act. Safety first. Safety always.