Colorful ceramic water cups are very flattering, but in fact there are huge hidden dangers in those bright paints. The inner wall of an inexpensive colored ceramic cup is usually coated with a layer of glaze. When the glazed cup is filled with boiling water or beverages with high acid and alkalinity, some aluminum and other heavy metal toxic elements in the glaze are easily precipitated and dissolved into the liquid. At this time, when people drink liquid with chemical substances, the human body will be harmed. It is best to use natural color cups when using ceramic cups. If you can’t resist the temptation of color, you can reach out and touch the color surface. If the surface is smooth, it means that it is underglaze color or underglaze color, which is relatively safe; if it is uneven, use your fingernails to dig There will also be a phenomenon of falling off, which means that it is an on-glaze color, and it is best not to buy it.