Is Jianzhan Tenmoku cups and sets safe?

Is Jianzhan Tenmoku food safe? Are Jianzhan tenmoku tea cups and sets poisonous? Does the fancy glaze of the Tenmoku cup safe? The pattern of Jianzhan is stunning, but the making process is safe? 

You may have many questions for those new to Tenmoku, and It doesn’t matter. We will answer them one by one for you. Let’s give our conclusion first: Jianzhan Tenmoku is safe and completely non-toxic.

1.The safety of materials

Porcelain making requires a large number of raw materials and glazes. The materials for firing Jianzhan are mainly local lateritic clay. The local laterite is non-polluting, harmless, and safe material. Its main component is hematite, which is iron oxide. 

In addition, it contains only trace elements such as calcium, phosphorus, potassium, and manganese. There is also a very important glaze in the raw materials. The glaze is made of maroon ore, a specialty of Jianyang. The maroon ore contains iron, quartz, feldspar, and other components. 

The Jianzhan Tenmoku glaze is mixed with powdery maroon ore, water, and plant ash; all of them are natural materials. Jianyang is one of the best places in China. The local forest coverage rate exceeds 70%. The raw materials of Jianzhan are taken from nature, which is the basis for the safety of Jianzhan Tenmoku.

2.The unique pattern of Jianzhan – the safety of iron elements

The main feature of Jianzhan is its unique pattern, so how is it formed? Is it safe? The glaze color of Jianzhan is derived from the crystals formed by iron elements. Due to the uneven heating of the base cup, different crystals will be formed on the glaze surface during the firing process. 

This is where the special glaze color of Jianzhan comes from. Iron has a strong color-making ability. Many gems and jade look bright because of the iron content. The red color of human blood is also due to the high iron content of hemoglobin.

3.Is the firing process harmful?

The process of firing a Jianzhan Tenmoku cup is complicated. The temperature is as high as 1300 degrees Celsius. The glaze can crystallize only when fired at such a high temperature. So we get different forms of iron components (iron oxide, ferrous oxide, ferric oxide, etc.), which have different colors. 

Under such high-temperature firing, harmful substances will be melted. As long as it does not contain heavy metals, then the Tenmoku tea cup is safe. The local laterite in Jianyang is free of heavy metals such as lead and cadmium.

4.The QC process

The daily-use porcelain is in direct contact with the human body and needs to be used under “high temperature,” so the requirements for safety are higher. The quality inspection standard of Jianzhan is the heavy metal residues of lead and cadmium. 

Because Jianzhan is a local industry in Jianyang and provides large jobs, the local government strictly manages the Jianzhan industry. Products on the market are regularly tested to see if they are safe. Chinese customs will also test exported products to ensure that unsafe products will not be exported. 

The importing country’s customs will also test the product to ensure that harmful products are not imported into the country. With their joint efforts, the Jianzhan Tenmoku cups you bought are 100% safe, and you can use them confidently