Fact Sheets

Ionization Smoke Detectors

The Off-Site Source Recovery Program, or OSRP, recovers excess and unwanted radioactive sealed sources as part of the National Nuclear Security Administration’s Office of Global Material Security. Radioactive materials can be found in common household items such as smoke detectors. Ionization smoke detectors in particular use a small radioactive source as a key component for detection of smoke particles. The radionuclide used in ionization smoke detectors is americium-241 (Am-241), which is bonded to a metallic foil and sealed within a small chamber. Using the ionization smoke detectors as directed poses no radiation health risk. However, it is essential to dispose and discard of these smoke alarms in the appropriate manner to avoid the potential spread of radioactive contamination.

Identifying an Ionization Smoke Detector 

There are different types of smoke detectors and some do not use any radioactive sealed sources. For example, photoelectric smoke detectors use a light and sensor to detect smoke and do not contain any radioactive material. However, many smoke detectors may use both ionization and photoelectric features to achieve maximum detection.

To determine if a smoke detector contains radioactive material, different indicators may be used. Observe the labels and markings on the original packaging or on the back of the smoke detector; and refer to the owner’s manual. 

Any of the following verbiage indicates that the smoke detector contains radioactive material: 

• The radiation symbol in any size or color.
• Radioactive
• Ionization
• Americium or Am-241
• Microcurie or μCi
• Becquerel or kBq
• Nuclear Regulatory Commission or NRC

If none of these markings occur, chances are the detector is photoelectric only and does not contain radioactive material. 

Disposal of an Ionization Smoke Detector 

Never tamper with an ionization smoke detector or attempt to remove the radioactive source!

Besides the obvious potential for spread of radioactive contamination, once the americium source is removed from its holder, it becomes extremely difficult to arrange proper disposal. Some municipalities allow exempt, non-regulated quantities of radioactive material such as smoke detectors to enter their landfills. However, not all municipalities authorize disposal of ionization smoke detectors, or they may have specific limitations. Therefore, OSRP recommends that all unused ionization smoke detectors be returned to the manufacturer or distributor directly. 

Company contact information is provided in the owner’s manual of the smoke detector; and the name and/or address of the manufacturer also usually appears on the back of the detector. Contact information for several manufacturers and distributors of smoke detectors is provided below and returning unused devices to the retail store where the purchase was originally made is also an option. Always contact the manufacturer before sending old smoke detectors. Some manufacturers have special return requirements. 

Manufacturers/Distributors