Experts Warn When Leftover Water Becomes Unsafe

The rumor about water remaining in cups for several hours and its impact on health varies in terms of severity. Studies indicate that leaving water in a cup for more than 12 hours may promote bacterial growth, especially if the water is contaminated or left exposed, which could pose a risk to the digestive system. However, drinking water that has been left for over 12 hours is generally not considered highly dangerous under normal circumstances, but it is advisable to replace it after a full day to prevent the growth of contaminants, particularly when sharing cups or bottles with others. It is recommended not to re-use cups or bottles that have been used by more than one person, and to avoid leaving remaining water in a cup for extended periods to prevent the transfer of bacteria and diseases. The recommended maximum duration for keeping water in cups is 12 hours; after that, it’s best to replace it to ensure health safety.