Smoke detectors can be one of two kinds: photoelectric or ionizing. The ionizing variety contains a small amount of radioactive material, americium-241. Although more expensive, homeowners should consider purchasing the photoelectric variety to avoid future disposal problems.
Smoke detectors with an ionizing sensor will usually indicate on the back of the unit that it should not be disposed of in the regular trash. In this case, the unit should be returned to the manufacturer (which should also be listed) for proper long-term disposal.
If the manufacturer is no longer in business or is not willing to accept the used detector, household smoke detectors may be disposed of in the trash. To prevent the smoke detector from accidentally being broken, wrap the unit in several layers of newspaper and carefully place in the trash. The battery should be removed from the unit prior to disposal.
These procedures are intended for smoke detectors from a household only.