The most common type of smoke detector contains a small amount of Americium 241, a radioactive material. On your wall, this material poses little threat; however, when a detector is broken open in an incinerator or a landfill, it can present .a health hazard. For this reason, all detectors, by law, must be labeled as to radioactive content. Detector companies must accept returned radioactive detectors for disposal as hazardous waste.

Homeowners can mail smoke alarms/detectors back to the appropriate manufacturer (see listing below). They should be marked "For Disposal" and sent by surface or UPS ground mail (not air mail).