You've probably heard that you shouldn't drink water after it's been boiled again.
It is believed that re-boiling increases the concentration of salts in water, forming dangerous fluoride compounds, etc.
At the same time, there is an opinion that the harm of repeated boiling is exaggerated.
Is it true that you can't boil water twice?
Experts agree that there is no need to worry about re-boiling.
The established standards for the content of salts and fluoride in drinking water are such that their concentration is far from dangerous values.
To reach a dangerous concentration, water must be boiled many times, not two, not three, not four.
For example, to make water dangerous due to increased fluoride content, 40 liters would need to be evaporated to the volume of a cup.
