Just to clear up a little bit of confusion about Tritium and to put things in perspective.
It's 12.5 year half life means that after that period of time your H3 sights will only glow half as brightly. After 25 years it's intensity will only be a 1/4 of what it was originally, and so on.
H3 itself, while it is a radioactive substance, is extremely weak and won't even penetrate your skin. However, it could be fatal if one were to ingest it.
Prior to H3, Radium was used to activate the luminous material. Radium has a half life of about 1600 years, so after 800 years it will still retain 50% of its brightness. Unfortunately, Radium is much more dangerous than H3 and even low doses can be fatal and cause major health problems.
As I mentioned earlier, I like SL because it glows much more brightly than H3. This is especially useful in low light situations where your pupils are not fully dilated. Of course if you're carrying your gun in a holster all day, something not possible for me here on the Left Koast, SL may not be right for you.
For those of you who would like to experiment with it, here are two links below from a watch supply house. The first link is for the complete kit. Just scroll down to the Super-Luminova kit. This kit contains the powder, the glue and a thinner. Otherwise you can click on the second link and buy just the powder (the refill) and mix it with a little bit of 5 minute epoxy and paint it where you want it. I went the latter route after removing the white plastic inserts from my Walther P99.
FYI the white SL glows the brightest. It's slightly off white under day light, and glows bright green in the dark. The blue SL appears slightly blue green under day light and glows a bluish green in the dark. While the initial intensity of the blue is not quite as bright as the white, it does seem to last longer before it needs additional exposure to light.
FWIW Rolex and most other Swiss watch companies use the white SL, also known as C1 and Citizen and a few other watch companies use the blue or blue/green, known as C9 and B2. See Tritec's link below for more on the different colors. Note that all the other colors glow a lot less brightly than the blue and the white.
http://www.ofrei.com/page737.html
http://www.ofrei.com/page972.html
http://www.rctritec.com/index.php?id=17