You sure about that? This website disagrees:
http://www.straightdope.com/columns/read/2135/is-heavy-water-dangerous
“Despite the fact the light water and heavy water are chemically identical, heavy water is mildly toxic. How can this be? Since heavy water is heavier than normal water, the speed of chemical reactions involving it is altered somewhat, as is the strength of some types of bonds it forms. This affects certain cellular processes, notably mitosis, or cell division, due to the difference in binding energy in the hydrogen bonds needed to make certain proteins. Mouse studies have shown that drinking only heavy water along with normal feed eventually causes degeneration of tissues that need to replenish themselves frequently, and leads to cumulative damage from injuries that don’t heal as quickly. One study likens the effects to those suffered by chemotherapy patients. Heavy water toxicity manifests itself when about 50% of the water in the body has been replaced by D2O. Prolonged heavy water consumption can cause death.”
I read somewhere else that it’s specifically the hydrogen isotope that causes problems. (With other isotopes the proportional difference in mass is too small to matter much.)
You asked, yet did not refute what I said. Ok then.
–adjective
1. of, pertaining to, affected with, or caused by a toxin or poison: a toxic condition.
2. acting as or having the effect of a poison; poisonous: a toxic drug.
–noun
3. a toxic chemical or other substance
Water, of and by itself, is Toxic. Over drink it, it will KILL you. Heavy water, either deuterium or tritium, behaves chemically the same as light water. The difference is that the other two forms of water use an isotope of hydrogen that is radioactive.
So, is heavy water toxic? Drink 20 gallons in an hour, probably so. But then light water would be too. For all intents and purposes, it is not. So, listen to fear mongers. Please stay away from all heavy water (Not possible, as it does occur naturally, but let’s not confuse this issue with facts). And do remember, even light water is toxic and dangerous.
Mouse studies have shown MANY substances to be toxic, but in everyday concentrations, not so much. Actually, it is the white mice that cause cancer.
Breathing straight oxygen is VERY dnagerous, don’t do that, you may burst into flame.