Comment by pclmulqdq

I think that's pretty much it but IANAL. Tritium vials are available for sale for use in self-luminous products. The vials themselves are pretty expensive for what they are, and they come with documentation about who initially created the vial (or how it was imported).

I have a gun with a tritium-based night sight (so the sight dots glow with no light), and it came with documentation about the provenance of each of the three tritium vials.

I also believe it is a crime to break open a sealed tritium vial.