Everything is dangerous especially when it is compressed or
concentrated. Even very nice people are dangerous when the are kept
in a very small area or overcrowded space! If this is a knew concept
for the silver or goldsmith, then one didn't make his homework. When
someone starts with a making jewelry without knowing the real facts
of the material his dealing with, then you're in a bad position.
I've been talking with a person who's filling gastanks mentioning the
deadly position he's encountering everyday by all the different
gasses. The guy answered that there wasn't a danger at all IF (!!)
you know what you're doing. Anyway, that job is not appealing to me
but he can sleep well with all those bombs next to his house. In my
case, I feel myself safe with my tanks because they're stored in a
save place and I shut them down every single day when I'm done with
making jewelry. Following the precautions for the gasses I use make
me sleep well.
By the way, to much salt can kill you, smoking too but people keep on
using it. Be aware but not affraid and act wise.
Have fun and enjoy