Stainless steel cup tea wall easily corroded

As the weather gradually cooled, many people’s cups changed from glasses to stainless steel cups. However, recently, online exposure claims that there is a danger of chronic poisoning in stainless steel cups, which has also attracted the attention of many netizens. It is so terrible to use tea in a stainless steel cup. The truth is really true. Yesterday, the CCTV reporter conducted a number of experiments.

Reporter experiment

Stainless steel cups will release heavy metal chromium

CCTV reporters first conducted a street interview and found that many people are using stainless steel drinking cups. Many citizens indicated that stainless steel cups are relatively clean and sanitary. Even if they fall to the ground, they will not rot and the weather is getting colder. It is obviously not appropriate to drink hot water from glass cups. Is it appropriate to use a stainless steel cup to make tea? CCTV reporters then conducted some experiments.

The reporter first got a brand new stainless steel cup, soaked tea in it, covered the cup, and stored it for 72 hours. 72 hours later, the reporter opened a stainless steel cup, flipped the cup and found that the inner wall of the cup was clearly corroded. Insiders have previously stated that tea contains a variety of chemical components and that the use of stainless steel cups will cause a chemical reaction.

Stainless steel cup contains chromium, which is a heavy metal, corrosion of stainless steel cups because the protective film is destroyed, chromium will be released, if sustained use will cause harm to the human body. According to experts, chromium is a blue-and-white polyvalent metal element. Commonly used are divalent chromium, trivalent chromium, and hexavalent chromium. Hard and brittle, anti-corrosion, so it is mostly used in stainless steel and other products.

If the body's long-term intake of trivalent chromium, it will affect the body's antioxidant system, easy to get some chronic oxidative diseases, such as diabetes, high blood pressure and other diseases. In addition, because the antioxidant system is damaged, diseases such as abnormal proliferation of tumors are likely to occur. Compared with trivalent chromium, hexavalent chromium is more toxic, about 100 times more than trivalent chromium. In clinical practice, the harm of hexavalent chromium and its compounds to the human body usually appears in three aspects. One is damage to the skin, leading to dermatitis, pharyngitis, etc.; the second is damage to the respiratory system, causing pneumonia, bronchitis and other diseases; the third is damage to the digestive system, eating and even long-term exposure to chromate, can easily cause gastritis, gastric ulcer and intestinal ulcer. Excessive intake of hexavalent chromium, but also lead to kidney failure and even cancer.

Experts reminded that stainless steel cups should not be used to make tea. Not only that, it is also best not to use stainless steel cups for vinegar sauce vinegar.

Expert reminds

The poorer the quality of stainless steel products, the easier it is to be corroded

Experts said that the quality of stainless steel cups is good or bad, and the worse the quality of stainless steel cups, the easier it is to corrode. How do ordinary people judge the quality of stainless steel products in their daily lives? With three stainless steel vessels found from citizens' homes, CCTV reporters walked into the laboratory of the School of Biological Engineering of Xihua University. The quality of stainless steel products is exactly what the experts have also done in a professional way.

Experts first found a stainless steel identification agent and applied it to the surface of the stainless steel product. If the identification agent rapidly changes color, it means that the quality of the stainless steel is not high. On the contrary, the slower the color change and corrosion, the higher the quality of the stainless steel. At the scene, the reporter noticed that stainless steel products coated with stainless steel identifying agents all exhibited a certain degree of corrosion. No matter how they were wiped, they could not be restored to their original shape. Obviously, such methods are not suitable for ordinary households.

Experts then said that using an ordinary magnet can also identify the quality of stainless steel. If the magnetic properties of stainless steel products are very strong, it proves that it is almost pure iron. Since it is iron, the appearance is so bright, it shows that it is electroplating products, not real stainless steel. True stainless steel products also contain iron, but also a little magnetic, but the magnetic is relatively weak. This is due to the fact that the iron content is relatively low, and on the other hand, after the surface coating, it has the property of preventing magnetism.

In addition, there is a small trick that can identify stainless steel products are qualified. First prepare a lemon and pour the lemon juice on the surface of the stainless steel product. After 10 minutes, wipe off the lemon juice. If obvious marks are left on the surface of the stainless steel products, it indicates that the stainless steel products are of poor quality and easily corroded, thus releasing chromium and endangering human health.