All of these items are glazed with food safe glazes. I have used food and drink pottery with these same glazes in my home – they are not delicate, but they are not Pyrex or commercially produced ware. Because these vessels are created from low-fire clay, it is strongly recommended that they be hand-washed. Oven/microwave/freezer use is highly discouraged due to the large changes in temperatures which may damage or destroy the pottery.