Water so pure it will kill you | Hacker News Reader

Water so pure it will kill you

nuscimagazine.com

24 pointsxk349 comments

I don't buy this, I think it's just an urban legend. Note that they provide no references for their claims.

I heard similar claims about drinking distilled water decades ago, and determined that they were BS by self-experiment. Now, it does make a certain amount of sense that ion-free water could be problematic for biological systems, but distilled water is already close enough to ion-free (with respect to a typical biological system, which in some sense is just "very dirty water") that I can't see how further purification could possibly suddenly tip it from "just fine" to "so toxic it will kill a goldfish in seconds". In fact, form a biological perspective even rain water is pretty close to ion-free.

Right. Ultra-pure water is, indeed, extremely pure ... but even tap water is already very pure by the standards of blood, or intra/extra-cellular fluid. The difference between UPW and tap water is nowhere near enough to make it dangerous to drink, save in quantities that are already objectively dangerous to drink tap water: osmotic pressure depends on differences in concentrations, not the absolute level of purity.

> I can't see how further purification could possibly suddenly tip it from "just fine" to "so toxic it will kill a goldfish in seconds"

First of all plopping a gold fish just like that into a new tank sounds bad. It is possible the temperature shock killed it.

My other guess would be the lack of oxygen. Ultrapure water used in litography is degassed to prevent the formation of small bubbles. No gass, no oxygen, that can also easily kill a fish.

The temperature might well matter :-) My minds eye has a picture of a goldfish lithobraking into a wall of solid ice.

I think I agree with you that distilled/ultrapure water wouldn't be harmful, but I think it would be okay only due to consuming electrolytes in food. I bet the amount of salts/minerals you need in food increases if you only drink distilled water. And I bet if you fast and only drink distilled water, you would eventually get sick/die.

So I have lived this experiment. Back when I lived on a submarine in the US Navy, when we went out to sea for several months at a time we made all of our own drinking water and I was the person who ran the distillation plant. When you run the plant almost continuously for months straight in the open ocean, it produces cleaner and cleaner water as the plant's essentially continuously flushing itself. After several months, the water in our potable water tanks would pass all the tests to be pumped straight into the nuclear reactor. All the scum that grew inside the potable water tanks would slowly die, as it had no nutrients to live off of. So the whole crew was drinking Type 1 pure water. When new people came onto the boat mid-deployment, they would often get diarrhea, but they'd acclimate and they'd be fine after a few days. That is my (unscientific) eye-witness first-hand lived experience. I wouldn't be surprised if a fish were very unhappy living in pure water, but I seriously doubt a fish would die in ten seconds.

Very interesting. Any idea how pure water could cause diarrhoea?

guessing the sudden imbalance of salts between the body and the incoming pure water would cause some reaction, maybe it triggers some sort of 'poison' response? that would cause vomiting too though

It might have been the food?

Would love to hear more about your experiences in a blog post

Was this water also properly aerated? Fishes do breath the dissolved oxygen water. So was the issue it being too pure or that it couldn't get oxygen?

My understanding is merely pouring the water into the bowl stirred it enough that it should have had sufficient oxygen.

So if it's oxygen deprivation that killed the fish, that says something like the water can't actually dissolve oxygen? Even for ultrapure water that can't much be true can it?

> that says something like the water can't actually dissolve oxygen

Diffusion from 0% might make the oxygen level low enough that it suffocates the fish, even with a casual perturbation.

I thought Goldfish go to the top of tanks and 'gulp air' to get extra oxygen. Or so I assumed – does anyone know why they do it for sure?

Dumbest shit I've read this week.

If you want some UPW, fabs have the best. The thing is that engineering and operating for industrial quality without attention to detail for human consumption would be a dangerous gamble to bet one's life on.

Tap water in thousands of US communities is negligently polluted, poorly regulated, and the regulations are inconsistently inadequate. If an water producer were honest, they would release easily replicable test data every month to prove they're managing input stream changes correctly. 5 of my extended family members and some of their loved ones died from uranium and other heavy metals contamination in the Four Corners area. Flint MI is not an exception, it's just a more concentrated and egregious scenario that happens more often but more diffusely and rarely connected manner.

On a much smaller scale, this is the same reason why distilled water is widely not recommended for use for espresso machines. Its lack of minerals will attract metal ons from internal parts of the espresso machine, which can cause corrosion.

Distilled water is also said to taste bad on its own from the lack of minerals.

One reason given for why Starbuck's Americanos taste good is because of their water filtration[0] (as long as you 'leave room' and don't add anything else).

[0] https://www.tastingtable.com/928069/why-starbucks-water-tast...

very interesting topic but really crappily written / organized / formatted / produced article.

can we have Derek Lowe write this article instead?

(edit: this Derek Lowe: https://www.science.org/blogs/pipeline not the pro baseball player)

The instant pure water touches your mouth, it's no longer pure.

"Right! Because it leached from your body!"

You have to drink soup or eat steak to avoid having any diffusion/leaching from introducing a less concentrated solution (water) to a more concentrated one (your body). If there is any validity to this idea, any way it might be true under special-enough conditions, this article does not provide anything that shows it.

The goldfish story is utterly meaningless as any aquarium owner will tell you.

It's like a mysticism that's the inverse of the mysticism in homeopathy.

Is it just me, or are all the pics in the article the same picture?

It may look like the same picture of a water purifier, but actually the water it contains is sequentially purer and purer the further down you scroll.

I chuckled. Thanks :)

You have to find the seven errors.

Does not answer the key question of how much ultrapure water will kill a human. Immersion killed a goldfish, but humans don't immerse themselves all that often, and cost would prohibit filling a bath tub with it, much less a swimming pool.

Would a standard US 8 fluid oz glass of ultrapure water kill? If it would, this seems like a good mystery novel gimmick.

Fair Warning; second hand story

Yes, just drinking some will do damage. I've heard of a non-tech seeing 'water' and ignoring the rest of labels and warning and drinking very pure water. Had to be sent to the hospital.

https://en.wikipedia.org/wiki/Water_intoxication

It happens with any water, but IIRC it happens faster with pure water by washing away electrolytes and disturbing signaling.

Right, Wikipedia lists LD50 of 90mL/kg (~5.5 liters for topical human). I am incredibly suspect that a single glass of pure water would do anything measurable. Hell, you can drink substantial amounts of D2O for a significant duration before metabolic processes begin to be impacted.

When I was in elementary school, there was some water drinking challenge

And the teachers warned against it, and someone told about a child dying from drinking just one liter of tapwater

I'd be interested to see a MSDS that says that ultra-pure water is a hazard. I find a lot saying it's not. Pretty sure that what you heard about was either apocryphal or one of those "out of an abundance of caution" scenarios.

Drinking a lot will be harmful, but not drinking a glass.

What a relief!

If the goldfish story is true, it probably died from a lack of oxygen.

Does drinking water contain any nutrients not adequately available from a normal diet?

I am extremely skeptical of the osmosis story told in the last two paragraphs, as I am doubtful that there is that much difference between clean soft drinking water and ultrapure water.

Maybe if you drank only ultra pure water and ate no food. The osmosis story is clear BS. The instant the water hits your mouth plenty of bacteria and electrolytes from salivia are reintroduced, not to mention all your digestive juices.

If you injected the pure water directly into your bloodstream, you'd have an osmosis problem, thus the need for saline in IVs.

David Blaine says he drank only distilled water for 44 days [1], if that's true, it should be pretty safe to drink.

[1] https://www.happyscribe.com/public/the-joe-rogan-experience/...

From the end of TFA.

“If ultrapure water was consumed continually, epithelial cells would be steadily leached (or perhaps instantly in the case of the goldfish’s respiratory system).”

Basically it would scour cells from you digestive system, roughly equivalent to corroding it away. It would probably take a few liters or more, but it would also probably hurt like hell.

> Would a standard US 8 fluid oz glass of ultrapure water kill? If it would, this seems like a good mystery novel gimmick.

If the pure water gimmick doesn't work out, then maybe for your mystery novel switch over to heavy water, which is known to be toxic iirc. Eccentric, recluse, rich person decides to drink nothing but heavy water for the exotic allure and then dies on the eve of a corporate merger or something. Bonus points, heavy water ice cubes will sink in regular water but over time they will float because they melt off the heavy ice and refreeze regular water, changing their buoyancy. Something the eagle eyed investigator can notice in the 11th hour.

Did they oxygenate the water before putting the fish in it? Is there paper in the printer? Did they turn it on?

Maybe this could be made to make sense, after a fashion.

Deuterated (D) water (heavy water) is apparently toxic if you get too much of it. I think the figure I heard was if it's over about 50% D2O in the D2O/H2O then it will kill you given enough time. D2O is still oxygen plus hydrogen so still qualifies as water, so I think it could be factually argued that pure water as D2O is fatal.

https://en.wikipedia.org/wiki/Deuterium

Ah, sort of slightly right: https://en.wikipedia.org/wiki/Heavy_water#Toxicity_in_humans

Side note: reverse process happens when you drink seawater: it sucks the water out of your cells, making you die from dehydration faster than if you hadn't drunk it.

My dad has been in wastewater for 25 years. He has the highest grade level in California for treating wastewater. He told me that the water leaving those plants is safe to drink and sometimes even more pure than regular tap. It is just the idea of drinking the water that causes people to post this stuff.

Would I drink the stuff after it left a plant? Not on your life.

I don't believe that distilled water can be dangerous to drink. Maybe if it replaces all of your intake.

If I eat any food and then drink a glass of water it is no longer pure. It's not like most of it is absorbed through my tongue or something.

https://youtu.be/IukTiqAqVBM

Junk science

>This is hugely important to daily life, unless you drink and shower exclusively with bottled water (which is ~2,000 times more expensive than tap water, 2 times the cost of gasoline, and not subject to any form of federal testing).

Yeah, you can go to Flint and ask them how good federal testing is.

If you put something in the water, the water is going to dissolve a bit of stuff, and will now be impure water. So it is impossible for "pure water" to be dangerous in this way.

Isn't the dissolving the dangerous bit?

You think that mixing, say, the saliva in your mouth with the ultra-pure water is dangerous?

Yes? Because he water wants to break apart and bond with parts of your cell walls, destroying them?

I don’t think you understand how rare pure water actually is?

FUD stupidity.

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