How do I dispose of a smoke alarm?

Two Smoke Alarm Types:

First, you need to know what type of smoke alarm you have.  Smoke detectors typically fall within two categories:  photoelectric and ionization.  When it comes to disposal, old photoelectric alarms can be safely put in the trash, so long as you remove the battery first.  

Ionization alarms contain a small amount of Americium 241, a radioactive isotope.  When in use, these alarms are perfectly safe, as the radioactive material is shielded by a metal chamber inside the device.  If dismantled, however, the radioactive material can become exposed.  For this reason, you should never try to take apart an old ionization alarm.

So, how do I dispose of an old ionization smoke alarm?

Some local hazardous waste collection centers will accept ionization smoke detectors.  You can also try to send your old detector back to the original manufacturer. Locate the brand name and/or address on the back of the device, or find the information in the user’s manual.  After removing the battery, send the whole unit back intact (do not try to disassemble) with a note indicating that the device is intended for disposal.