Which is poisonous, underglaze or overglaze?

Overglaze color is poisonous. Overglaze color is made on glazed ceramics, and the pigment contains harmful substances such as lead and cadmium, which has not been fired at high temperature, and there is a great safety hazard. Using this porcelain to hold food may cause these harmful substances to be ingested into the body, thus affecting health. Under-glaze painting is done on clay blank, and then coated with a transparent and colorless glaze. Because there is glaze on the pigment, it will not directly contact with food, so it is relatively safer, but the glaze color is painted on the fired white glazed porcelain and then fired in a kiln at 600-900 degrees. Because it was painted on the glaze, it was named glaze color, which was first produced in the Song Dynasty and was widely used in Jingdezhen kilns in the Ming and Qing Dynasties. The varieties of underglaze colors are Doucai, Multicolored, Pastel and Enamel, while underglaze colors are painted with a layer of colorless transparent glaze on the carcass, and then returned to the kiln at a high temperature of 138. It is called underglaze color after painting on the blank, and it is called underglaze color after glaze firing on the blank. Painted on the glaze, it is called underglaze color after being fired in the kiln at low temperature. Common underglaze decorations are blue and white, underglaze red, underglaze tricolor, underglaze multicolor, underglaze brown and brownish green.