You know that's a good question, I couldn't imagine them being a problem but the TSA isn't a sane organization so who knows.
I have gone through tsa check points at several different airports with a green and a blue 23mm tritium in tec steel lanterns attached to a maratac aaa steel led light and they have never gotten a second look. Never inspected any more than the X-ray scan. No one has cared about them.
Should be not an issue, unless whatever it is, will appear as a threatening or dangerous item to whichever officer will be scanning it.
Theorically, there is an issue because Tritium is radioactive...But his radioactive decay it's very quick and the ammount of "product" in the FOBs is irrelevant... Source: Ablogtowatch/How Tritium Gas Tubes Are Made (I'm just kidding, I don't think TSA will complain about it... )
I think exposure to UV-A radiation is way worse than tritium, which pilots themselves often have on their watches.
I know if you have a stress test at your doctor they give you a letter that explains why you have detectable radiation in your system.
There is also the thought of 'how are they ever going to stop you?' Most tritium fobs are small keychains, and are pretty unnoticeable, and if they were tho be spotted by an interested TSA agent will just look like any glow in the dark keyring - unless someone *really* knows what they are looking for, or are scanning you with a geiger counter (though I will admit I am not sure if a tritium vial even puts out enough radiation to register) they are never going to know any different. I would be tempted to say though, that while I can't find any confirmation of it, a lack of any particular ban probably stands you in good stead - they tend to specifically list the banned items (or at least make an obvious category that they fall under) so the fact there is no mention whatsoever I would take as acceptance (or ignorance) Tritium is far from a new substance anyway, and has been used in things like watches and compasses for years without any outcry or prohibition, so that should say something too.
I know that there is a small amount of radiation that will make it out of the vial its self, not enough to be harmfull unless you eat it. I know with watches with tritium in them for lume the radiation is so minute it does not even make it out of the watch case.
I would be more worried that it would trip some sort of automated radiation detector and they wouldn't be bright enough to figure out where it was coming from and detain you for something
When I bought my tritium, they claimed it had less radiation than a cellphone. But who knows if they're telling the truth or not.
there is more than one kind of radiation as well so you never know which one they are talking about. when they used to use tritium paint instead of the tubes they use now, the people in the manufacturing plants would get radiation poisoning from it actually entering their body constantly. there were reports of the people painting watch hands actually licking the brushes to set the bristles back in place or something, so that's why I mentioned not to eat it, but the newer GTLT are made differently and don't have those problems
