Stainless steel is usually divided into food grade and non-food grade. Since non-food grade stainless steel contains more heavy metals such as chromium and nickel that are harmful to the human body, if it is used frequently, it is easy to cause harmful components to accumulate in the human body, which can easily cause skin allergies and cause patients to experience symptoms such as skin itching, rash, and urticaria. If heated, toxic metals will appear, which can easily cause patients to be poisoned after entering the human body, causing chest tightness, short-term breathing difficulties, etc.