Sodium hydroxide is one of the four strong bases, which has strong corrosiveness and can take away hydrogen and oxygen elements in substances. According to the composition ratio of water, it is 2: 1 corrosive substances. Be extra careful when using sodium hydroxide in the experiment. If you accidentally come into contact with the skin, rinse it with clear water in time and neutralize it with weak acid. If you accidentally fall into your eyes, you should seek medical attention in time, and you will be seriously blind. If you touch your face, handle it carefully, or your face will be severely disfigured.