"John Nickum" wrote :

Errr... ummm... beta particles, I meant beta particles.

I'll let you off :-)

I guess that they must be very low energy beta particles, because if
they were able to penetrate the glass, they'd never have gone on the
market, even in the 70s.


Yes, low energy, 0.018590 MeV. Cannot even penetrate skin, so only dangerous
if inhaled or ingested. The difficulty is that tritium is hard to contain
due to its propensity for diffusing through solids such as plastics, rubber
and even some steels.

Tritium decays to helium-3, which is non-radioactive, so you don't have to
worry about other decays down the line. Contrast with thorium, for example,
one of whose decay products is radon.

Steve S