I use the synthetic stuff that comes premixed. I get it at WalMart. I'm
under the impressio that it is not particularly toxic to the skin, but they
shouldn't eat it. (just like they shouldn't eat acrylic paint, ModPodge,
whatever) Which for toddlers would be a problem. I teach k-8. I have not
researched this product as far as toxicity, tho. I hope someone will
correct me if I'm giving out bad info.