Just curious to the watchmakers or hobbyists that find themselves regularly working with Tritium: do you routinely wear face masks, or feel that the amounts are so small, and the hands /dials often intact, to make this unwarranted? I just don’t know enough about this, but if it looks intact, does that means there’s not appreciable dust? And I would assume that the concern also drops if many half-lives have elapsed?
I would not worry about problems due to tritium dust, but its always good to protect yourself against inhalation of the dust
Yep massively so. The half life is only 12.3 years so the oldest tritium (first used ~1962) is now nearly 5 half lives old and thus only 3% as potent as it was when new*. The newest is ~23 years old or 2 half lives so only 25% as active. It emits mostly beta which isn’t as damaging as the other forms in low doses anyhow, particularly when ingested. If you must lick a dial (or inhale dust) pick tritium over Radium which remains a strong Alpha emitter. *this is basically at background level. I doubt you could measure this outside of a Uni lab. Any tritium lume watch before ~1985 poses v little risk IMO.