I use lead free, non toxic and dinnerware safe glazes on bowls, plates, cups, etc. and assume that food microwaved in them is safe, as safe as any microwaved food is. A customer recently wanted me to confirm this, so I thought I would put it out here.
Also, I have used dinnerware safe blues and greens for bowls, etc., but have a vague memory about someone advising against this. If glazes are labeled safe for food use, aren't they safe (regardless of color)?
Finally, in the past I called a glaze company about layering food safe glazes and I believe they said they could not confirm their safety because of layering. Aren't many many food pots presently made decorated with layered glazes? Can some be used in layering and others not?
THANKS FOR ANY ADVICE YOU CAN GIVE ME!!