Thanks for your reply.

I know that propylene glycol is non-toxic and ethylene glycol definitely IS toxic. But the tinting colors are used in housepaint and the ethylene glycol in housepaint evaporates and, at any rate, is in such small quantities in the wet paint that it would be negligible. I was mostly wondering if anyone had ever used these tinting colors for fine art? Making usable acrylic paint with them would be very much less expensive than tube acrylics. As the old (USA) ad says, “Just a little dab ‘il do ya!”