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                                                USA
Smoke  Detectors
Smoke detectors are a common household item. One type, ionization smoke detectors, use a small radioactive
source as a key component in detecting smoke particles. Photoelectric smoke detectors, use a light and sensor
to detect smoke. Ionization smoke detectors are more effective at detecting flash fires, while photoelectric
smoke detectors are more effective in detecting smoldering fires. Both cost about the same, and many smoke
detector models use both ionization and photoelectric features, to achieve maximum detection.
The radionuclide used in ionization smoke detectors is an oxide of americium-241, which is bonded to a
metallic foil and sealed in an ionization chamber. As long as you use the smoke detector as directed and do
not open it, it poses no radiation health risk to humans—always use a smoke detector in your home.
Americium-241 is a man-made radioactive metal, first discovered during the Manhattan project, the national
program that first developed atomic weapons during World War II. Americium-241 emits alpha particles and
low-energy gamma rays. The smoke detector alarm goes off when the flow of alpha particles is interrupted by
smoke particles.
Who is protecting you
The States
Each state has one or more programs that address radiation protection and the use and disposal of radioactive
material in consumer products.

U.S. Nuclear Regulatory Commission (NRC)
NRC establishes regulations for the licensing of the sale, use and disposal of radioactive material. The
requirements for a license for the use of radioactive material in a consumer product are based on the quantity
of the radioactive material and the specified level of radiation.

U.S. Environmental Protection Agency (EPA)
EPA's Clean Materials program is designed to monitor the ways radioactive sources enter the environment or
the nation's metal supply through improper management. EPA also works with the National Conference of
Radiation Control Program  Directors to develop ways to keep unnecessary radioactive material out of
consumer products.
What you can do to protect yourself
       Use a smoke detector in your home.  It can save your life.
       Never tamper with an ionization smoke detector or attempt to remove the americium.
       Replace the batteries in your smoke detector every year or as directed. Most detectors are certified for a useful
       life of ten years.
       Return outdated ionization smoke detectors, minus the batteries, to the manufacturer. The address of the
       manufacturer usually can be found on the back of the smoke detector. Most communities have a separate
       recycling program for batteries.
 United States Environmental Protection Agency
Office of Radiation and Indoor Air (6608J)  |   EPA 402-F-06-044
April 2006
                                                                 www.epa.gov/radtown/smoke-detector.html

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 RadTown  USA
Resources

You can explore this radiation source further through the resources at the following URL:
http://www.epa.gov/radtown/smoke-detector.htmltfresources

We provide these resources on-line rather than here so we can keep the links up-to-date.
 United States Environmental Protection Agency
Office of Radiation and Indoor Air (6608J)   |  EPA 402-F-06-044
April 2006
                                                                www.epa.gov/radtown/smoke-detector.html

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