Three things I tell my students, is that it is important to not lick your brush, drink the paint water or to wash the brush out in your wine (/coffee). Primarily this is because of the heavy metals in some of the pigments. Flake white was stopped being produced when it was discovered that lead isn’t good to eat. Cadmium isn’t terribly good for the digestive system either, but it is a metal that produces awesome reds and yellows from different salts; my chemistry doesn’t stretch to complete comprehension of the quinacridone range, but when you know that phthalo (you pronounce it ‘thallow’ – isn’t English wonderful!) blue’s full name is phthalocyanine blue, you might get a hint as to why brush licking isn’t advised.
But science comes to the rescue of art with replacement colors for the cadmium range that don’t contain the nasty wonderful cadmium! Liquitex isn’t my usual brand, but if Golden haven’t started introducing them by the time I’ve used all the cadmiums I currently have, I’ll definitely be giving them a try. Looks like this is only for acrylics at the moment, but something like this will likely catch on once the ban on cadmiums can be enforced because there’s a viable alternative.
Until I’ve completed the move to cadmium-free cadmiums though, don’t lick my paintings either.