Copper is a less reactive heavy metal element. It does not react with oxygen in dry air at normal temperature. In the humid air, a layer of green patina slowly develops on the surface of the copper. In long-term animal experiments, it is found that verdigris is not terribly toxic, it is insoluble in hot and cold water, and has extremely high stability.
Research by Japanese scientists has proved that even if the verdigris is ground into powder and injected into the human body, the human body will not absorb it. The body will excrete it through a natural reaction. Therefore, in today's scientific and medical progress, the conclusion that copper and "patina" are toxic should be corrected and re-understood.
Copper cups can drink tea, copper spoons can cook vegetables, copper pots can be stewed, hot pot... Even if a trace amount of copper is released, it is an important supplement for the body to need trace elements. However, because copper products are oxidized and rusted by moisture, they are easy to lose their luster, turn black and green, and require frequent scrubbing and maintenance. At present, copper utensils are rare, and are gradually replaced by stainless steel products with bright white appearance.