Answer to Question #8036 Submitted to "Ask the Experts"

Category: Consumer Electronic Products — Smoke Detectors

The following question was answered by an expert in the appropriate field:


I know that smoke detectors contain a radioactive material. My parents have always tested the alarms using a candle and blowing it out to let smoke enter. Is the smoke exiting the detector radioactive and does it pose a health hazard if you breathe it?


No. Smoke detectors are extremely safe.

Now, some more detailed information. Smoke detectors were tested extensively prior to being authorized for use in smoke detectors by the U.S. Nuclear Regulatory Commission (NRC), the agency responsible for licensing exempt sources of radioactive materials. NRC takes very seriously the concerns that the radioactive isotope americium-241 is in smoke detectors. However, before any amount of radioactivity was authorized in smoke detectors, NRC performed several technical analyses in the 1970s, 1981, and most recently 2001, to determine if NRC's earlier calculations regarding any potential health effects from use of such consumer products containing very small amounts of radioactivity would be detrimental before authorizing its use.

NUREG 1717, which is available on NRC's Web site, discusses the radiological assessment that NRC performed for smoke detectors and other types of consumer products. Radiation doses were estimated for the normal life cycle of the smoke detector, covering routine uses as well as inadvertent uses of the device (such as many thousands of smoke detectors burning in a warehouse fire).

Americium used in smoke detectors is embedded (fused) onto a layer of foil; it does not pose any danger to you or your family. This is one of the reasons NRC originally authorized its use in the 1970s. The americium-241 cannot be scraped off or inhaled.

For additional information you may also visit the Health Physics Society "Ask the Experts" Web site for additional information on "smoke detectors."

Orhan H. Suleiman, MS, PhD

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 19 March 2009. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.