Electric kettle is a common electrical appliance in life. Through the intelligent induction control of steam, it can convert electric energy into heat energy, quickly boil water, and automatically cut off power when the water boils. Electric kettle boiling water is usually harmless to the body, but it must be a qualified product. The electric kettle will be tested when it leaves the factory. The qualified inner container of electric kettle is generally food grade 304 stainless steel, containing 18% chromium and 8% nickel, with limited contents of various heavy metals. The metal composition is relatively stable, and no chemical substances will precipitate when heated at high temperature. In addition, the stainless steel liner produced by regular manufacturers can effectively sterilize and precipitate harmful substances, so it is harmless to human body. However, some hot water kettles are made of high manganese steel, which may precipitate manganese under high temperature, and long-term drinking will cause chronic manganese poisoning, so it is not recommended to choose high manganese steel electric kettles. When the temperature of the electric kettle reaches a certain level, harmful substances in tap water will precipitate, which will form scale after long-term use. Scale may contain heavy metal elements such as mercury and iron, as well as substances such as calcium carbonate and nitrite. Long-term intake may lead to stones or heavy metal poisoning. You can regularly use vinegar, scale remover and baking soda to remove the scale in the electric kettle, which is beneficial to human health.