http://hps.org/publicinformation/ate/q13412.html http://hps.org/publicinformation/ate/q13412.html Looks like the half-life of radioactive aluminum is only 2.3

http://hps.org/publicinformation/ate/q13412.html http://hps.org/publicinformation/ate/q13412.html Looks like the half-life of radioactive aluminum is only 2.3 minutes, should be safe after a day or two. edit add: https://www.madsci.org/posts/archives/2003-03/1046983737.Ph.r.html https://www.madsci.org/posts/archives/2003-03/1046983737.Ph.... And gold would only be unsafe for a month or two.