> Can you confirm or correct my impression that... something with half life of 12 months would be reduced by half in a  year, 
 by 3/4 in 2 years, by 7/8 in 3 years and so on ad infinitum.

And, moreover, if this takes into consideration the breakdown products and their half-lives?

Sometimes those products can be worse than the original product. (Not saying this is necessarily the case here).

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Access BEE-L directly at:
http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A0=BEE-L