It is rumored that tea scale will be produced after making tea, which will corrode the thermos cup and precipitate heavy metals, eventually leading to chronic poisoning.
Truth: a layer of dirt formed by the deposition of tea, which does not contain corrosive components. The stainless steel used in the inner wall of the thermos cup is an inert material, which is difficult to be corroded. Therefore, the "hot cup tea will precipitate heavy metals" is not tenable.
Then why does the tea made in the thermos cup have thick color, dark color, and bitter taste? It is because long-time high-temperature brewing accelerates the volatilization of aromatic substances in tea and affects the taste, which has nothing to do with "heavy metals" and "toxic substances".
When using the thermos cup, it is necessary to strictly prevent the breeding of bacteria. Because the inner tank of the thermos cup is relatively thick, a large number of bacteria will hide in the sanitary dead corner. After one day of use, it should be thoroughly cleaned. Put a little baking soda into the cup to wash the inner tank. After cleaning, the water stains in the cup should be fully dried and then covered with the cup cover.
Many people believe that drinking medlar water soaked in a thermos cup or carbonated drinks is harmful to the body because the acids, alkalis, and salts in medlar and carbonated drinks will corrode the cup and lead to the dissolution of alloy elements.
Truth: we can't put aside the dose to say the toxicity. Although medlar and carbonated drinks are acid-base, they are very weak. Even if they are soaked for several days, there is no need to worry about the dissolution of alloy elements for the standard stainless steel cup. Even if trace alloying elements are corroded and dissolved, chromium, nickel, manganese, molybdenum, and other alloying elements in stainless steel used in tableware are essential trace elements for our human body and will not affect our health.
If you soak medlar in high temperature (more than 80 ℃) water for a long time, many nutrients such as vitamins in medlar will be lost. Moreover, the effect of soaking medlar in water can not be brought into full play.
If the inner container of the thermos cup is made of high manganese low nickel steel, do not store carbonated drinks for a long time.