Smoke Alarm-ist

[Birchy]

Is it true that a domestic smoke alarm contains a certain amount of 'harmless' radioactive material? If so, what is it, and how harmless is it?

[rja211077]

check out http://science.howstuffworks.com/smoke2.htm no idea how harmful it is, but as long as you don't eat it i'm sure you'll be ok.

[bernardo]

Yes. There was a famous case of a student in the 1990s (there was a documentary programme about ti recently) who made his own home-made nuclear reactor out of household items - the key ingredient was the radioactive bits which he harvested from hundreds of smoke alarms. (He succeeded in making a few atoms of plutonium in his garden shed).

[thoma?]

i'm pretty sure his name was david hahn. not sure about the spelling of his last name though. also included in his reactor, or the making of his reactor were thorium mantles, and radium paint from old clocks. the really scary bit was that this guy did this when he was a teenager, almost no questions asked and all for a boy scout project. just google "radioactive boy scout" for the whole story...