i know Ubi
i used it for a while...
but you must know that tritium radiation is not so strong to pass plastic
so to use it are needed glows and to remember to use every time the same stick...
there are more risks using a dremel while polishing an iron case....
from wiki...
"Tritium presents no external radiation threat when encapsulated in non-hydrogen-permeable containers; its only danger is its constitution into the human body from direct contact, which may in turn cause long-term, low-dose radiation damage. This is because beta decay radiation from tritium is not very energetic; it is incapable of penetrating through glass containers or even intact human skin."
http://en.wikipedia.org/wiki/Self-powered_lighting
EDIT:
i found this ...
http://www.createthefuturecontest.com/page...tml?entryID=567