Tea scale is not harmful to the body. Tea dirt mainly contains tannins and a very small amount of metal elements. 1. Tea contains tannins are chemically unstable, easy to become dark after encountering oxygen, in the tannins continue to oxidize the process, and finally generate insoluble compounds tannin, tannin will slowly precipitate from the tea attached to the teapot on the formation of brownish-red tea rust, and tea scale is oxidized in the tea polyphenols and tea rust in the oxidation of the metal elements after the formation of the reaction. 2. 2. Although tea scale contains metal elements, because the content is very small, and precipitation in the wall of the teapot, so the amount that can be absorbed by the human body is very small, and will not cause harm to the human body. Although the tea scale is not harmful to the human body, but in order to hygiene and aesthetics Still recommend that we drink tea every time after the timely cleaning of the teapot or teacup.