Many people believe that boiled water is safe to drink no matter how long it has been stored. However, Dr. Deng Hongyun, Chief Physician of the Child Healthcare Department at the Tujialing Outpatient Clinic of Hubei Provincial Maternal and Child Health Hospital, has reminded everyone that boiled water should not be consumed after more than three days.
If water is stored for too long, it becomes infected with bacteria and produces nitrites. Once a large amount of nitrites enters the human body, it can cause tissue hypoxia, leading to symptoms such as nausea, vomiting, headaches, and palpitations. In severe cases, it can lead to death due to oxygen deprivation. Nitrites can also form nitrosamines in the human body, which can promote the development of liver and stomach cancer. Boiled water stored in a thermos bottle, once it cools down, provides a faster environment for bacterial reproduction and leads to the reduction of more nitrites.