Is black ceramic harmful to the body?

Nowadays, many families place some ceramic products at home, which not only makes everyone's home environment more beautiful, but also can cultivate everyone's sentiments. Ceramic products can also make people's home environment look more tasteful. Black ceramics is a type of ceramics. It is also a popular type among people and is also very common in homes. So, is black ceramic harmful to the human body?

There are two main reasons why porcelain may be toxic: one is the raw materials used to make porcelain, and the other is the firing process.

The raw materials for making porcelain include clay, glaze and paint.

The clay material is generally kaolin clay or pottery clay, which are relatively safe. The raw materials in this regard are basically natural, derived from natural clay or minerals, and the only difference is the quality.

The most likely areas where porcelain may be toxic are glazes and paints.

There are three methods for making ceramics: overglaze, underglaze and inglaze. The overglaze color process is relatively simple, so the price is relatively low. "Toxins" such as lead and cadmium present in ceramics mainly come from overglaze pigments. Lead, mercury, cadmium and other elements in glaze are harmful to the body.

Excessive cadmium dissolution can lead to cadmium poisoning in the human body and cause lung disease; excessive lead dissolution can lead to lead poisoning in the human body. In mild cases, it manifests as irritability, loss of appetite, personality changes, and abdominal pain. In severe cases, it can lead to kidney failure, slow reaction, gout, peripheral nervous system diseases, etc. For children, the harm of lead poisoning is particularly serious. In mild cases, it affects brain development, and in severe cases, it causes increased intracranial pressure, vomiting, convulsions, etc.

Another common problem that may cause porcelain to be toxic is the firing process. Whether the clay, glaze and painting materials are safe depends on the firing temperature. High-temperature porcelain is better than medium-temperature and low-temperature porcelain. High temperature generally refers to 1280 degrees Celsius to 1350 degrees Celsius. Under such calcination temperature, after passing through the oxidation and reduction atmosphere, general harmful substances disappear or are transformed. In other words, high temperature firing can be equal to safety.

So when buying ceramics, avoid buying some rare and cheap foreign trade medium-temperature porcelain with hand-painted patterns. The easiest way to distinguish high-temperature porcelain from medium-temperature porcelain is to observe the color, thickness, and listen to the sound.

First, look at the color. The glaze of medium-temperature porcelain is thin, with only a shallow layer of refraction, and you can even see the body color directly. Generally speaking, the painting is relatively rough, which is not only due to the craftsmanship, but also depends on the body quality and pigment characteristics.

The glaze of high-temperature porcelain is very moist and has a clear feeling, close to the refraction of high-quality glass (except for matte porcelain).

Then, look at the thickness. Generally speaking, good high-temperature porcelain is translucent and thin. Because the firing process of medium-temperature porcelain is low in temperature and the texture is loose, in order to improve impact resistance, the body will be relatively thicker.

Finally, listen to the sound. This relies more on experience. The so-called listening to the sound is to tap the vessel lightly with your hand. The sound of high-temperature porcelain is clearer and closer to the sound of metal. There is a sense of density in the sound, while the sound of medium-temperature porcelain is duller, which is determined by the density.

In the process of using porcelain, the tea soup seeps into the cracks and forms obvious lines, which are called "open lines". The type of tea and tea drinking habits will affect the color of the open lines. However, it is not known when some unscrupulous businessmen began to use ice crack glaze and then apply paint to directly complete the "opening lines". Unscrupulous merchants often add color to the bottom of porcelain plates to simulate glaze accumulation.