...china paints are minerals and flux - which is what? borax? lead? feldspar?

http://www.porcelainpainters.com/ppioclass/beglesson2/Page_2.htm

Guessing the main one to watch out for with regard to toxicity is cadmium...which seems to be used in all those nice bright reds and oranges...

Doesn't one pretty much have to swallow, breath dust, or absorb through open cut? Nitrile gloves would seem to eliminate skin absorption risk.

LATER: The dope on cadmium:

https://www.osha.gov/SLTC/cadmium/