1, look at the raw materials of ceramics
The raw materials of ceramics are clay (green raw material), glaze (glazed raw material) and painting (decorative raw material). The raw material of green body is generally kaolin or clay, which is basically safe because it belongs to natural clay or mineral and has no chemical addition.
In glaze, both underglaze and underglaze have a layer of glass body (glaze) wrapped around the painting material, which also contains possible heavy metal elements. The glaze color, because its pigment will directly contact with food, is easy to release heavy metal elements at high temperature, which is harmful to human body.
In most cases, painting materials are low-cost chemical materials, which may contain heavy metal elements such as lead and cadmium.
2. Look at the firing of ceramics
In addition to seeing whether the paint is in direct contact with food, it also depends on the firing temperature. Because in the process of high temperature calcination, harmful substances disappear after chemical reaction.
Glaze is a glass body formed by high-temperature treatment of glaze. After such high-temperature treatment (about 1200 degrees Celsius), heavy metal elements will not remain basically.
However, the firing temperature of glaze color is only about 800 degrees, which can not meet the above-mentioned "high temperature" conditions. In this case, the safety depends on the quality of the paint. The better the quality, the lower the lead and cadmium content.
Glaze is formed after high temperature, which is basically above 700℃ and basically non-toxic. But the painting materials are basically low-cost chemical materials, which will contain some heavy metals. You can touch this place with your hands. If the feeling is obvious, it is the glaze color and the underglaze color. The patterns are all under the glass.
Not all ceramic tableware is safe. Not all ceramic tableware is safe. Long-term use of some tableware will cause chronic poisoning of heavy metals, which will cause damage to skin, teeth, eyes, brain, bones and fertility. These harmful substances are mainly heavy metals such as lead and cadmium contained in ceramic tableware. The degree of harm mainly depends on the amount of these heavy metals dissolved in use and absorbed by the human body.
Precautions:
1, try not to use ceramic tableware with large patterns inside.
Never eat too sour and salty food with ceramic tableware with flowers in it.
3. Ceramic tableware that has been left for a long time should be cleaned before use and wiped with hot water.
4. Try to dry or dry ceramic tableware after cleaning.
Never use ceramic tableware with flowers in it to store food for a long time.
6. Don't cook food at high temperature with ceramic tableware with flowers in it.