Myths about water: Is repeated boiling of water harmful and does it lead to heavy water?

You’ve probably heard many times from acquaintances or even parents that you can’t boil a kettle of the same water several times? You have to pour out the water, pour in new water, and only then boil it again and drink it. What is this? A tradition, an urban legend, or a superstition? If anyone can explain why it is not necessary to boil the same water twice, the formation of heavy water is often mentioned. But is it true that boiling the same water multiple times can lead to so-called heavy water? Will it happen if you boil water ten times or a hundred times?

What kind of water is there?

First, let’s understand what heavy water is that everyone is so afraid of. Heavy water is heavy hydrogen water, aka deuterium oxide, consisting of an oxygen atom and two atoms of deuterium, which is a heavy isotope of hydrogen. Apparently, this is where the name heavy water comes from.

Heavy water itself exists in nature and its concentration is about 0.015%, i.e. it is so in the water we drink and in ourselves, because we are composed of 80% water. It turns out that in itself, it’s content in us and not harmful, but inherent in nature.

So how does heavy water form?

The best known method of its occurrence is by multiple electrolysis, i.e. the physical and chemical process of releasing the constituent parts of dissolved substances on the electrodes. It turns out that it is not repeated boiling that produces heavy water, but repeated electrolysis, which is obviously not the same thing.

But the process of boiling also leads to an increase in the concentration of heavy water in ordinary water! How much does each boiling increase its content? Scientists, who evidently had heard about the myth of occurrence of heavy water by boiling, calculated that in order to increase its concentration by 10 times, i.e. up to 0,15%, one should pour into the kettle, in which water is boiled, 2,1 multiplied by 10 to the power of 30 tons of water. First of all, how long does it take to boil that much water? Not enough time in a lifetime for sure. Secondly, that much water simply does not exist on Earth.

And should we be afraid of this very heavy water? In fact, it is not as toxic as, for example, table salt. In addition, a person can drink 3 glasses of heavy water without any harm to the body, which then disappear from the body without a trace in a few days.

And so, the myth is destroyed! Repeated boiling of water does not lead to heavy water, and the heaviest water is not lethal to the body at all. So if you are afraid that the cooler will produce heavy water while maintaining a constant high temperature, discard your fears and bravely drink water from kettles and coolers without fear of anything.