Speaking of why washing hands with soap must be "running water", Zhang Zhiying, a cardiologist at the First Affiliated Hospital of Tsinghua University, said that people need to wash their hands with soap or hand sanitizer, because only in this way can pathogenic microorganisms such as viruses or bacteria float on their hands, and then they can be washed with running water from the faucet to effectively wash away these bacterial viruses floating on the foam. This is because when we wash our hands with a basin of water regularly, no matter how many times we wash them, these pathogenic microorganisms may remain on our hands again with the water in the basin, making our hands look clean to the naked eye, but in fact, bacteria are still everywhere. In addition, some people are used to washing their hands with the same basin of water, and they are likely to find cross-infection.

Therefore, whether in a special epidemic or in daily life, we must pay attention to washing our hands with flowing water. If this step is missing, hand washing is also white washing.

At home, when we wash our hands with soap, we will get used to the whole family using the same soap. In fact, such behavior is also an unhealthy habit and should be avoided as much as possible.

Because many people use a piece of soap together, even if the soap is more alkaline, most bacteria can't survive on it. However, if the first person does not clean the foam left on the soap after using it, the bacteria and viruses stored on the foam may attach to the soap, and cross infection may occur when the second person uses it again. In addition, when we use soap, we must pay attention to keep it dry and hygienic, especially the box for storing soap. Because according to a recent study in the United States, soap will breed a lot of bacteria in a humid environment.