I could just throw them away, which is probably what a lot of people would do -- people who are careless, uncaring, or possibly illiterate. Such a person would fail to read the label on the inside of the detector that tells them to return the detector to the manufacturer for disposal. As a licensed Mechanical Engineer, with a minor in nuclear engineering, it is a moral issue for me -- I have to properly dispose of these detectors. I can now pass the buck to Sears, and they can figure out how to extract the 5.0 micro Curies of americium from all the plastic and dispose of it. Hopefully, there is enough plastic structure around the americium so they do not achieve critical mass if stored to close together. (I am not sure what to do with two old watches with radium hands.)
Ten years from now I will have to repeat this, but the new detector from Builders Emporium does not state where it should be send for disposal. There is good news, though; the new one only contains 1.0 micro Curies of americium -- which, it states, is equal to 37 kilo Becquerels of radiation. (Our efforts to metrify strike again -- Curies have become Becquerels. I know who Madam Curie was, but who was Becquerel?)
I also find it interesting that my expired detectors were made in Hong Kong, and the new one was made in Taiwan. It leads me to ask several questions. How can something made of americium be built anywhere but in America without being unpatriotic? When the new humongous accelerator is built, will they name any new heavy elements hongkongium or taiwanium? Are smoke detectors illegal in nuclear-free New Zealand? And since radium is radioactive, how do New Zealanders read their wristwatches at night?