If Liangbaikai is left in the air for a long time, it will produce a large number of bacteria. But in fact, after boiling water, 99.9% of bacteria can be basically eliminated. In clean and tidy air, the growth of bacteria is very slow, even impossible, so even if it is boiled overnight, there is no need to worry about being infected by bacteria.
Some people think that exposure of cold boiled water to air for a long time will greatly increase the content of nitrite in boiled water. Many people were frightened when they heard that cold boiled water would contain nitrite overnight. Actually, it's not necessary The nitrite content of cold boiled water overnight is very low. If it is a container with a lid, it is even more worrying.
However, if it is cooked cold, bacteria in the mouth will enter cold cooking. If it is left overnight, there is indeed a danger of bacteria breeding. So try not to drink water overnight.
You can drink cold boiled water overnight, but you can't drink these three kinds of water.
1, raw water
Raw water passing through water pipes will carry all kinds of bacteria and parasites. The human body itself can't kill these bacteria and parasites, and it is easy to cause acute gastroenteritis, viral hepatitis, parasitic infection and other diseases.
2. Boiled water.
The tap water we usually drink is sterilized. Chlorine-treated water can separate out many harmful substances, some of which are harmful and may cause cancer. When the water temperature reaches 90℃ to 100℃, the content of halogenated hydrocarbons in water will increase greatly, which greatly exceeds the national drinking water hygiene standard. When the temperature reaches 100℃, harmful substances will be greatly reduced with steam.
3. Boiling water
After repeated use and boiling, the concentration of nitrite in this water will be high. Drinking this water often is likely to lead to nitrate poisoning. After the scale enters the human body, it will also cause pathological changes in the digestive system, nervous system and urinary system.
References:
People's Daily Online "Can boiled water be drunk overnight?"