Can You Drink Heavy Water?

Commonly used in some types of nuclear reactors, heavy water is considered unsafe by most people. While these concerns may be genuine to some extent, not everything talked about heavy water is true. To better understand if you can drink heavy water, here are some important things to keep in mind.

What is heavy water?

While standard water that we use every day has 'protium' isotope of hydrogen, heavy water has the 'deuterium' isotope of hydrogen. Both are stable isotopes of hydrogen. While standard water is represented by H2O, heavy water is 2H2O or D2O. As compared to protium that has a proton in its nucleus, deuterium has both a neutron and a proton in the nucleus. The presence of an additional neutron makes deuterium atoms weigh almost double to that of protium atoms. This is how heavy water got its name.

In certain types of nuclear reactors, heavy water is used as a moderator to control the speed of fission reaction. This helps sustain the nuclear reactor in a safe manner. Heavy water is also used for various other applications such nuclear magnetic resonance, infrared spectroscopy, neutrino detection and metabolic rate testing.

Is heavy water radioactive?

It is generally believed that heavy water is radioactive. However, this is not entirely true. Heavy water produced in a factory is not radioactive. It may become radioactive only after it has been used inside a nuclear reactor.

Can you drink heavy water?

If you are drinking pure, uncontaminated heavy water, then yes, you can drink heavy water without any issues. There will be problems only when you are exposed to heavy water derived from a nuclear reactor. However, there's a limit to how much heavy water you can drink before getting sick.

Pure, uncontaminated heavy water can be harmful only when the heavy water content in your body reaches 25% to 50%. As is apparent, a glass or two of pure heavy water cannot lead to things like poisoning. To reach 25-50%, large amounts of heavy water will need to be ingested for several days.

Heavy water atoms are found naturally as well, but they constitute only around one atom for every 6,400 hydrogen atoms. Based on that, we can calculate that an individual weighing 110 lb. will have 0.039 ounces of deuterium atoms. To reach 25-50% ratio of heavy water in human body seems quite impractical.

In lab experiments conducted on rats, mice and dogs, bodily heavy water levels of 25% have shown to cause sterility. 90% concentrations have shown to kill living beings like tadpoles, flatworms and fish. Mammals like rats have died when heavy water levels reach 50%. Fatalities linked to heavy water are primarily due to cytotoxic poisoning. This is due to deuterium's ability to inhibit cell division, even though pure heavy water is not radioactive.