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topic 15665

Is DI Water safe or undrinkable?


Q. I read some responses on here to "what are the differences between DI Water and distilled water. Good question? The reason I ask is that we use DI Water for cleaning parts on the Ion Implanters (semi-conductor field). Why not regular water or distilled? Also I have been told not to drink DI Water? Why? We drank distilled water (I believe) when I was on a US Submarine. What is the difference and why can't I drink DI Water?

Dan MacLellan
semiconductors - Twin Falls, Idaho

Distilled water
Deionized water


A. Hello Dan.

Distilled water is made by boiling water until it turns to steam or water vapor, collecting that steam and then condensing it back to water. The theory is that contaminants that were in the original water will not vaporize and become part of the steam, but will remain behind as a residue in the first pot. This is true of general dirt, but may be less true for volatile organic compounds in the water. You may have heard of double distilling or triple distilling (perhaps in whiskey making); in that case you repeat the distillation process to get purer water (or purer alcohol).

An alternative to distilling is the deionizing process: the contaminated water passes through two columns full of ion exchange media, the first of which is saturated with sulfuric acid, the second with sodium hydroxide. The H+ from the sulfuric acid replaces any cation contaminants in the water, while the OH- from the sodium hydroxide replaces any anions, with the idea being that only fairly pure water gets through.

If ultrapure water is needed the water may then flow to a "mixed bed" deionizer where thousands of grains of cation exchange resin are mixed with thousands of grains of anion resin. The idea is that this is equivalent to passing the water through thousands of cation exchangers and anion exchangers in series.

Some people feel that deionized water (especially if a mixed bed deionizer was used) is so pure that it is very aggressive and unsafe to drink. Others feel that concern is silly. For my part, I wouldn't be comfortable drinking water that comes out of a tube that was recently filled with liquid caustic or concentrated sulfuric acid :-)

Ted Mooney, Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


A. You can drink it, without the slightest worry. Search the archives of this site - the matter has been clearly explained.

Bill Reynolds
Bill Reynolds
   consultant metallurgist
Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.

Water Treatment: Principles and Design

Vertical Color Changing DI Adder Kit


A. I would be unhappy drinking either de-ionised water or distilled water. As Ted says, de-ionised water is made by passing it through ion exchange columns, one of which contains sodium hydroxide. This can enrich the water with sodium ions and this is bad news if you are health conscious. Too much sodium in your diet is definitely not a good idea -it can lead to high blood pressure and other associated problems. This is why you can buy low sodium salt, which is actually potassium chloride. As far as distilled water is concerned, again as Ted says, it is made by boiling out the salts. What you need to remember is that water is a damn good solvent, especially for salts, so if it is free of any dissolved salts, it will dissolve anything it comes into contact with. Consequently, when you put distilled water in your mouth, it will start to dissolve the minerals in your teeth and I am sure you dentist will not recommend this. If you put a little bit of distilled water on our tongue, you may feel the salts being dissolved from it - it tingles! I cannot answer for submariners because I have never been in the navy, but I would hope they would not use pure distilled water to drink - perhaps they doped it with bromide?

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK


A. I do not agree with Mr. Reynolds on this matter. Deionized water is not safe to drink. Due to the purity of the water and the lack of minerals, DI is a relatively strong solvent. As such, when ingested, a condition called "osmotic shock" may occur. This condition occurs as a result of the DI water removing minerals and other elements from the cells in the body more rapidly that the cell walls can stand. The result is ruptured cells and internal bleeding. Though the cases are few and far between, there have been documented cases.

Best of Luck,

Ira Donovan, M.S.F.
Kansas City, Missouri


A. The following is cut from a letter in the archives of this site. I think it explains the situation very well.


"As for the relative potability of the pure waters, the difference in waters is very small. There is no adverse health affect from drinking distilled or deionized water. Deionized water tastes kind of bland & somewhat insipid, and distilled water has no taste at all. Some people get used to these qualities & drink them all the time. In either case, the taste is improved by aeration--if you shake the pure waters up with some air, the taste improves. The taste of any given water is largely imparted by the various mineral components; many of the drinking waters on the market today are, in fact, purified tap water to which minerals have been added (Avalon, etc). By law, drinking waters can not have more than 1000 parts per million of dissolved solids, so when you get down to the analysis of most available waters, there really isn't much difference between tap water, mineral water, or purified waters (no nutritional difference at all between any of them!) As far as the health issue is concerned, it is true, water is hypotonic to cells & will destroy them. However, tap water is also hypotonic to cells. Your skin & stomach & intestinal linings are perfectly suited for thriving in and processing water. If you were to inject water into your blood, cells would die. If you cut your skin & wash the wound, the exposed cells do die. Fortunately, the fats that lyse out of the exposed wound quickly makes the wound less susceptible to water damage. Any ultrapure water you drink will quickly dissolve some saliva from your mouth--as soon as it has dissolved few parts per million of any substance, it is no longer ultrapure anyway. If it is a concern & all you have to drink is ultrapure water, you can stir the water with a metal stainless spoon or your finger first & it will magically transform itself from ultrapure water to just water."


Bill Reynolds
Bill Reynolds
   consultant metallurgist
Ballarat, Victoria, Australia


A. I completely concur with Ira in that "the DI water removing minerals and other elements from the cells in the body." Bluntly, depending on the size of the individual, drinking over a certain volume of DI water causes diarrhea and stomach cramping. : (

Mary Cera
- Oklahoma City, Oklahoma


thumbs up signWhat happens if one drops a copper iridium coin in the ultra pure water.. does the person cease functioning? Would one have to then wrap oneself in carbon paper to get moving again?

Marc Green
Marc Green
anodizer - Boise, Idaho


All righty then. Between this thread and searching the archives:

Dangerous: Thomas Baker, Trevor Crichton, Ira Donovan, Michael Majancsik, Tim Neveau, James Totter, Mary Cera.

Harmless: John Holroyd, Anand Jayaraj, Bill Reynolds, Dale Woika

Clueless: Ted Mooney.

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey



You forgot one, Smart-Alec: Marc Green

Marc Green
Marc Green
anodizer - Boise, Idaho


thumbs up signI nominate Marc Green for the award. Doesn't matter what water you start with or what you want to finish with, the coin will fix it!

Trevor Crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK


Let me see - the opinions of the people that are actually water experts say no, and material scientist and the like say its fine.

I say flip the copper iridium coin and pick a side. Me, I'm going the way of safety. I mean, I only have about 200 signs in our inventory that say "Deionized Water - DO NOT DRINK" and by LAW in all 50 states, they have to be posted. Either this is a cruel joke on my clients or someone knows what some of others of us do. But hey, maybe life is different down under. I mean, your little whirlpools that occur when you flush the loo go in the wrong damned direction, so maybe your DI water is safe to consume.

p.s. Hey Bill, keep on drinking that DI water and we can watch Darwinian Theory in real time. Me, I know DI water can make for a really crummy beer, and tap water makes perfectly wonderful beer. Go figure...

tom baker
Tom Baker
   wastewater treatment specialist
Warminster, Pennsylvania


Ok... now that I'm done laughing at Thomas' reply (with ya.. not at ya, buddy) I have to put my 2 cents in...I wouldn't drink anything that will corrode stainless steel....nuff said.

Marc Green
Marc Green
anodizer - Boise, Idaho


Hi, Tom.

Those who claim D.I. water is dangerous are not all water experts, nor does the other side lack water experts and people with specific medical experience in this.

It is dangerous to drink ANY industrial water because it is not protected by backflow preventers, will have no germ-killing chlorine, and is a breeding farm for bacteria; UV systems are often needed to keep DI water free of blooms. So the "Do Not Drink" signs are completely appropriate . . . but the signs don't necessarily imply that the authorities have found that drinking D.I. water will lyse or explode a dangerous number of cell walls.

These kinds of laws rarely have science on their side anyway. A few years ago it became illegal for NYC restaurants and butchers to use wooden cutting boards because it was "obvious" to the authorities that the cracks and gouges would accumulate germs and toxins. Then, after the old world chefs of the world's greatest city were stripped of their heirloom cutting boards and compelled to switch to generic plastic boards and "stop selfishly risking the public health for their vanity", only then was it time to actually test the premise; and only then was it recognized that, unlike wood, plastic is an oleophillic surface that does not clean well like wood, is certainly not safer than wood, and may in fact be a serious hazard as a fertile breeding ground for food-borne bacteria and illness. Of course, the regulatory authorities who wasted taxpayer money banning wooden cutting boards are certainly not going to commit any research funds to proving that they were smug, know-it-all, blundering idiots -- so that was the end of that. Obey the law, post the signs, and don't drink water intended for industrial use -- but I'd look for documented animal tests demonstrating osmotic catastrophes rather than relying on wild conjectures.

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

April 6, 2009

Tom Baker:

The way that the water in your toilet swirls is controlled by your toilet design, not which hemisphere your toilet is installed in. The toilet shoots the water into the bowl at an angle, which determines which way the water swirls during exit.

Some old text books referred to hemisphere as the determining factor of swirl direction of a gravity drain, like a bath tub.
The reason given is the Coriolis effect, which has to do with the way that the Earth rotates out from under something that moves freely, like water or an object in flight. However Coriolis is too weak to come to bear on your tub water.

Steve Rose
mechanical engineering - Minneapolis, Minnesota


Q. I read the discussion regarding the safety of drinking RO/DI water, which stimulated my question. I have an RO/DI unit in my garage to make water for my reef tank. The ice maker and drinking water dispenser in my fridge already has a feed line from the cold water pipe on the hot water heater which runs down the wall directly behind my tank. I was wondering if it would be safe to "T" into the ice maker feed line from the RO/DI unit to supply both the sump under the reef tank for top off water and supply the ice maker/drinking water dispenser. The water that enters the refrigerator goes through an inline carbon filter before it enters the refrigerator/freezer. Would carbon filtration Re-Ionize the water this way and make it safe to drink?

Scott M. Breitenbruck
reef aquarium hobbyist - Winter Park, Florida


A. Hi people,

I read an article in "New Scientist" [link is to info about the magazine at Amazon] some time back about ice spikes, including how to make your own. Empty your freezer, and fill your ice cube tray with distilled water, and they grow as the surface freezes. Needs to be really clean water. So I went to buy distilled water, and could only get DI water. My ice spikes didn't work, but from now on, I will be eating DI ice-cubes. The bottle from which the water came says "Warning: Not to be taken." There is no poisons warning, health information, MSDS notes or anything anyplace on the bottle. I am quite sure that it is not regulated as a food product, and therefore cannot be sold as such, but for AU$1.39 for 2 Litres, it is much cheaper than spring water. I'll let you know if any adverse effects arise.

Michael Smith
- Sydney, NSW, Australia

Trihalomethane Cholera



- THOUSAND OAKS, California


A. I'm sure that every water expert is familiar with the hazardous reactants that can be produced when water is chlorinated, Bob.

The thing is, every process and every decision has both advantages & disadvantages. Comparing the tens of millions, maybe hundreds of millions of lives directly saved from cholera through the introduction of widespread chlorination of water, against the dangers of chlorination byproducts, you're right: virtually every public water supply which looked at that balance chose to chlorinate.

Nothing wrong with bottled water (except perhaps for the waste associated with having to transport it), but it's not a substitute for chlorination of municipal water supplies. You don't wash your dishes and bathe in bottled water, do you? If not, I hope you use chlorinated water rather than non-chlorinated water, which could spread fatal diseases.

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


Q. It is well understood that DI or Distilled water is not safe for drinking. The REVERSE OSMOSIS drinking water also may or may not be safe. Since it reduces the TDS to a very low level of 30-40 mg/liter, it may again be hungry water extracting salts from the cells of body. So the question is what is the safe limit of TDS IN WATER for drinking purpose?

- Delhi, India


A. I don't think you can say "it is well understood" after reading this letter, Rayja, wherein many knowledgeable people deny it. I don't know whether it's harmful or an old wives tale -- but I do know that it is not 'well understood' :-)

Sorry, but to try to skip this hotly debated point of whether it is qualitatively harmful at all, and jump into trying to quantify how many ppm of TDS is safe doesn't seem reasonable.

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


A. I have an RO filter (with an optional DI unit) at home for drinking, cooking, and for the icemaker. It has a separate spigot for 0 ppm DI water. Having a background in biochemistry/biomedical research, I find this thread truly interesting.

I've never seen a sign in research labs that says, "Caution, Deionized water, DO NOT DRINK", but I probably wouldn't drink water from a lab where chemicals (some dangerous) are being mixed. -Biomedical researchers just walk over to the rented water cooler/dispenser to have a drink, and I imagine the bottled water is reverse osmosis combined with multiple stage carbon filtering and ozone or UV sterilization, and has a content of 6-12 ppm solute (6-12 mg/liter dissolved salts).

Ion exchange media that is used to make DI water from RO water, it will remove all solute, and will leave +H & -OH ions, yes. But they should combine (& neutralize each other) to form a molecule of water. I believe food grade DI resin should be harmless, as it would be free of any chemical impurities.

Doing a search on the AMA, (American Medical Association,, or the ADA, (American Dental Association,, there seem to be no references to warnings re: de-mineralized of de-ionized water. The ADA has a page re: recommendations to use fluoridated demineralized/deionized water to make up a bottle of baby formula, but that's about all.

My wife is a dentist. She said, "Deionized water might be dangerous? Really?"

I would agree that drinking "unbuffered" de-mineralized water when you really needing hydration, may cause absorption & dehydration problems (such as when you're working up a sweat from running a race). In this case, your body needs electrolytes for proper hydration. So, add a sport drink powder to your DI or RO water. Eh, Voila!

Pure water (de-ionized or de-mineralized) is probably (for the most part) less harmful to a person than soda pop, and doesn't have trace amounts of harmful chemicals that bottled water drinkers are wanting to avoid.

RO/DI water is the purest form of water that a household or modern submariner (or Space Shuttle Astronaut--guess where they get their water!) can obtain.

If you're worried that unbuffered water will kill cells for some reason, water filter companies sell an inexpensive "re-mineralization" cartridge that can be added to your RO or DI unit. Inside is a sand like media, similar to crushed coral skeleton. It should buffer & replenish your water with desirable minerals, and balance any pH issue you may be worried about.

I am not a professional water quality specialist. I'd be interested to see some medical/scientific documentation on the subject. The drinking water market is big $$, and accompanied by much marketing propaganda from more than one side. Bottled water is cheap to make, yet sometimes costs as much as fruit juice or gasoline.

2 cents.

Dasani bottled water is deionized water, filtered with RO/DI. It measures 0 ppm solutes.

Mohri Barizo
- Meridian, Idaho


Q. Hello everyone. I have an RO/DI system to make water for my reef tank.
I am planning to take 50 gal tank and make my own drinking water. According to Dr. Natasha Campbell Mc-Bridge, the best water has minerals and bacteria in it. I always knew not to ad shells to fresh water fish tank because it raises the water hardness, so I want to put there some shells for the minerals leeching into water, and a teaspoon of Himalayan salt. But how to handle the bacteria part? I think to live it along.

Jerry Szal
- NY River, Long Island, New York

January 30, 2008

A. Ok, to clear this up. I have done extensive research on the use of RO, RO/DI, Distilled, and tap water. According to everything I have found, the following is true:

DI water in manufacturing facilities usually have chemicals added to prevent bacteria formation and pipe corrosion. Therefore, that is why there are "Do Not Drink" signs.

RO water is completely save with no effects. It can be used without any concerns.

DI and Distilled water do have some concerns. The "pure" water is safe. However, it should not be an only means of hydration. It does "leach" minerals (salts, etc.) from the body which is bad over a long term. Most people do not drink only water. They will have tea, coffee, sodas, etc.. that can replenish those minerals (as well as foods). You cannot live on DI/Distilled water alone, but you can drink it as long is it is not the only water you drink.

Tap water has many nutrients added, and is not harmful in any way. It provides fluoride for the teeth, but with any type of water, you actually can get water poisoning (hyperhydration) if you drink too much of any type of water because it leaches the electrolytes from your body.

Hope this helps

Skaife Jones
- Fernandina Beach, Florida

Dasani water

March 8, 2008

As a physiologist/biomedical researcher, I must say the last post is interesting, but written by an individual with a "little bit of information".

Tap water may contain trace elements that are undesirable for long term human consumption, so many people are turning towards RO or even RO/DI water for drinking. Dasani bottled water is an example of RO/DI water.

Pure water, such as deionized water, does not contain these tap water contaminants, such as lead, arsenic, or chloramine compounds. It does not contain anything. It is also a fallacy that DI water will "leach" minerals from a person's body.

DI water may not be the best liquid to drink when maximum absorption is needed, as one may need some electrolytes (salts) to aid in absorption, but DI water will not hurt you, unless you're drowning in it.

Hyperhydration (or water poisoning) can only occur under very extreme conditions, such as drinking 5 gallons of water in a day.

David McConnell
hobbyist - San Diego, California

March 10, 2008

A. Well, Well. This is an interesting conversation that I can put to rest ...

I am not a water guy, I am not a scientist or and engineer nor do I claim to know more than anyone else on this site.

I worked in the Chemlab Clean Room in Lagrange GA of a major company about 8~9 years ago. Every time we came to work we had to put on a ridiculous clean room suite that covered us from head to toe including a veil for our neck and goggles [linked by editor to product info at Amazon]. The bad part was when it was time to take a break or go to the bathroom in the 10 minutes they allowed, it would take us 7~8 minutes to completely disrobe and to put the dang thing back on when we came back from break. this left us 2 minutes to use the bathroom and to get a drink.

After doing this for my first week I said forget it and I decided to just have a drink from the DI system. I thought, what could it hurt, it's just water? Right?

I drank about 2 glasses of it over the course of 2 hours and about 30 minutes before the lab closed, I started to get very sick at my stomach. I was walked to the bathroom by my supervisor and I threw up blood all over the floor. I started to produce Flu Like symptoms after a bit and I got very weak. They called an ambulance and took me to the hospital. After a 8 hour stay in the ER, I was informed that Drinking De-Ionized water caused this.

It turns out if you have ulcers in your stomach that drinking DI water will make you Really, Really sick.

I can't speak for those that don't have Ulcers as to what it would do, But I say don't drink the stuff. If water contacting blood can cause these types of problems, I would not drink It!

Please also keep in mind that this was a Chemlabs DI system and it was top notch. However they were lacking, the "Do Not Drink DI Water" Signs that are Federally mandated.

The lab got a good fine for that one! We found the sign behind the DI unit the next day covered in Dust.

Enough Said, you can stop the argument now.


Matt Morman
- LaGrange, Georgia

Ed. note: Hmm, three people in a row presenting the absolute final word on the topic :-)

June 3, 2008

A. I have been reading the arguments here. For those of you who do not believe in drinking DI water, what do you think is in every canned or bottled beverage you drink ?There may be a significant difference in individual water treatment systems, but like anything else, it depends upon the due diligence of the owner / operators.

At the very least bottling plants for beer and soda use acid / base water treatment.

Chlorinated water ? Would you prefer cholera, or dysentery ? More soldiers died in war from disease (mostly from foul water) than from wounds.

As for the gentleman with the ulcers, do you know that several large American drug marketing companies spent millions of dollars trying to discredit the two Australian doctors who proved that a simple course of antibiotic treatment would cure ulcers ? When large amounts of money are involved, some people don't care who they hurt, do they ?

John Biava
- Rockford, Illinois

November 26, 2008

A. This is a very interesting topic. With a lot of different opinions. I will come from a different perspective. In my line of business, I have commercial customers that use DI water for precise applications (lab, experimental, chemical etc). Then I have the bottle water companies, water stores, and residential improvement customers that purchase Reverse Osmosis units for drinking water.

From what I have been told by Certified water specialist that number one, there is no true pure water. Since water is the greatest solvent on earth, any thing the water touches will partially dissolve in the water. Second, the only true way to remove most of the contaminants in water is through either RO or DI. To my knowledge DI just removes the metallic Ions from the water, but uncharged particles remain in the water. Where as RO water through its various filters will actually remove the contaminants.

I have not heard of anyone drinking DI water, and it does not sound appealing to me. For the past 10 years I have consumed RO water (Sparkletts, Dasani, Aquafina, etc. are all RO purified water). I have not had any medical problems with cells bleeding, the runs or anything else.

I guess when it comes down to it, it is whatever you want to drink. I will never drink tap water. I have read too many water analysis reports to know not to drink tap water. RO is the way to go in my book!

Brian Turner, Water quality supply sales rep
- Fullerton, California

December 7, 2008

Q. I am a home brewer who became interested in treating my local water because its mineral content was unsuitable for the varying types of beer I like to brew.

Given that RO/DI water is also unsuitable, I began calculating mineral additions and considering possibly adding a mineral cartridge to my RO/DI system.

After some trial and error and calculations/tribulations I concluded I could formulate/simulate nearly any brewing water in the world by blending my my carbon filtered tap water with my RO/DI water.

It has proven through trial and error to be an effective way to achieve a desired mineral profile and I have had good success brewing varying beer styles with this method.

If your concerned about drinking DI water, why not do the same with your drinking water? Is there a technical reason why this method of adding minerals back into RO/DI water would be ineffective?

Jerry Smith
- Belleville, Illinois

December 10, 2008

A. In matters like these it is always a good idea to recall Paracelsus' words on toxicity: "All things are poison and nothing is without poison, only the dose permits something not to be poisonous." And of course the dose will always depend to some degree on the particular individual.

Additionally, there is a big difference in control and testing between chemicals produced for industrial purposes and chemicals produced for food purposes. I would not eat or drink anything that was meant for industry; regardless the grade of purity or cleanliness.

Sverre Pettersen
optoelectronics - Trondheim, Norway

December 26, 2008

Q. So, I found this thread because I was trying to find out if it was alright to use distilled water in my radiator. I have a 1999 VW Golf TDI diesel, and the G12 coolant bottle says to mix with 'deionized or soft' water. So, I'd be happy to have anyone's opinion! Thanks!

Jim Taddeo
veggie-cars - Cincinnati, Ohio

February 12, 2009

A. A couple of facts:

Sodium and Potassium
These are the major body electrolytes. The fluid in body cells is high in potassium; 90% of the body's potassium is inside the cells. Other body fluids are high in sodium.

Fluid Sodium Content Potassium Content
Blood 3,100 - 3,330 mg/L 137 - 200 mg/L
Sweat 575 - 1,725 mg/L 155 - 200 mg/L

The concentration of Sodium and Potassium in Dasani Bottled Water:
Sodium content = 2 mg/L, Potassium = 3.5 mg/L

The concentration of Sodium and Potassium in DI water:
Sodium content = typically 0.01 mg/L, Potassium = 0.01 mg/L

The concentration of Sodium and Potassium in Gatorade:
Sodium content = 395 mg/L, Potassium = 150 mg/L

The leeching of electrolytes from your body into the liquid you drink is proportional to the imbalance between your body electrolyte content and the liquid you are drinking.
Let's take as the average for body blood and sweat (Sodium = 2182 mg/L, Potassium = 173 mg/L)

Hence the imbalance for Dasani drinking water:
Sodium imbalance = (2182-2)= 2180 mg/L imbalance
Potassium imbalance = (173-3.5)= 169.5 mg/L imbalance

Hence the imbalance for DI water:
Sodium imbalance = 2182 mg/L
Potassium imbalance = 173 mg/L

There is practically no difference in leeching electrolytes when drinking Dasani purified bottled water and DI water. Both will equally drain your body of electrolytes.
The only way to avoid to drain your body of electrolytes is to drink water that is matched to your body in electrolyte content, such as Gatorade (more or less).

Steven V [last name deleted for privacy by Editor]
- San Francisco, California

January 5, 2010

Q. So....can I drink the water or not?

Erik Walczak
- Buffalo, New York

January 2010

A. Hi, Erik. Obviously you can drink it -- but many people have told you that it's dangerous, if not from dearth of ions, then at least because it is industrial water without proper safeguards against backflow, bacteria, and disinfection.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 10, 2010

A. DI water immediately out of the closed loop circulating system is safe for OCCASIONAL drinking, i.e., to relieve a cough or something like that. Continuous drinking of DI water will leach ion minerals from your body and therefore I would not consider this safe or healthy.

The problem with DI water is after it's out of the closed constantly circulating loop there isn't much to inhibit the growth of bacteria. I do not know what the bacteria growth rate is in DI water compared to RO or distilled or tap water but I have always been told that non-circulating DI water is much more susceptible to bacteria growth. So DI water that has been sitting in a glass for any length of time or sitting in faucet static, without moving, I absolutely would not consider safe for drinking or use of any kind where there is a need for ion/contamination free water.

I can only find general references to this on the web but have been told this for the last 25 years so there is probably at least an element of truth to it. I would not be surprised if some types of bacteria count doubles in under 20 min after DI water has been sitting.

Don McIntyre
Semiconductor mfg - Starkville, Mississippi

June 16, 2011

A. If you are lost in the woods without fresh water would drink lake water? My answer is yes I have and lived to tell about IT...bacteria and all. In my opinion this argument not about "should or should not" it is more what is safe to drink verses what is healthy.Yes there are healthier water choices than DI water but ... DIE of thirst, OR drink DI water?
it is up to you

Rob Cowtan
artesian water - Ottawa,Canada

July 15, 2011

thumbs up signOn a science test at school, there was a question: What is hard water?

My answer: ice

John Sykes
- Philadelphia, Pennsylvania, US

September 8, 2011

A. I drink steam distilled water ... for 40 years now and look younger than virtually everyone of my contemporaries and all of my younger siblings.

Paul Bragg ND and many other pioneers of natural health who consumed distilled water lived long healthy lives, some into their 90s.

The solids in distilled water may be useful for plants, but do little for humans. If you want minerals, eat high brix fruits and vegetables.

Harold Merkins
- Cambridge, Massachusetts, USA

January 6, 2012

A. Those who claim RO/DI water is harmful are incorrect. Here is why:

The tap water does contain some very minimal minerals our body required, but heck, other than those minuscule "good" minerals, the rest are extremely harmful, such as arsenic, copper, lead, radioactive materials such as Iodine 129, Cesium 137.

I also doubt that by ONLY drinking tap water will suffice your daily mineral intake as 99% minerals were getting from fruits & vegetables. If you were deficient in certain mineral, it is definitely NOT because you've been drinking too much RO/DI water; most likely, you need to change your diet, be it on tap water or RO/DI water.

If the lack of mineral of RO/DI water still has somewhat scientific background (despite I've busted it) The other often claimed part is this so-called "leaching mineral ... bursting your cell" stuff:

Even if by drinking 100% pure water made from burning Hydrogen and Oxygen in an enclosed burner will not harm you in any forms of "leeching your body minerals" as the moment the water reaches your mouth, your nasty saliva will immediately dissolve any pure water that gets contact with it, and brings ppm from 0 to over thousands in a matter of milliseconds! It also alters your water pH value and it should be no more or less corrosive (mineral leeching) than the tap water you've been drinking for eons!

Then, you've swallowed this already 1000 ppm, pH balanced *water* down to your stomach where nasty stomach acid was so concentrated that it lowers your pH value to somewhat around 2, and not to mention other body fluid such as gallbladder fluid, intestines fluid kicks in before finally the water can be absorbed in large intestine which is already as messy as it can get and if it's about to leech any minerals within your cells.... You must be already badly deficient on lots of minerals and I doubt under that condition, you'd be OK to get out of bed and fetch yourself a cup of RO/DI water, you must be in ER already!

Conclusion: if you were mineral deficient, it's your diet or digestive system problem, NOT RO/DI water. If you were sick and need minerals, tap water is NOT a good source for so and so. Taking pills is much wiser than drinking from heavy metal polluted tap water in order to cure some *deficiency* and your doctor will probably agree with me.

Xuan Lu
- Toronto, On, Canada

January 21, 2014

A. I'm an Analytical Chemist and work with DI water every day. I cannot claim to be able to put this debate to rest however, I can shed some real world light on the subject as well as fact. Ironically almost all the posts have some element of truth to them.

Scientific fact: Many harmful bacteria and viruses are altered by charged species attacking the functional groups and consequently rendering the bacteria as no more than harmless organic/organometallic matter. The same reason bleach or peroxide are effective antibacterials. Since DIW or MilliQ will have ultra low levels (ppt and sometimes ppq) of ions (both positive and negative) growth will be extremely elevated. Unless the DIW system contains truly harmful contagions this will not kill you, you will experience some diarrhea. The osmosis discussion while it is true DIW does in fact leach ions from your cells the most impactful consequence is in the muscles. ATP is used by the myosin filaments in the muscles to "contract" and the release of phosphorous to make ATP from ADP is controlled by Sodium. Consequently DIW will lead to lower levels of Na and cramping, the level of cramping will depend on the amount of DIW consumption. If you were to be extremely dehydrated to begin with and decided to drink bacteria free MiliQ (ppq pure) water you would experience very minor cell ruptures. One of the previous posts cited particle levels for some Dasani bottled water versus DIW, those are inaccurate. I use the most cutting edge analysis techniques known to man and can tell you that the DIW we have here has total ions of consistently less than 1 ppb and Dasani water (which I have in fact tested) has total ions of at least 50 ppm depending on the batch; some have been much higher. In other words it would take 50,000 gallons of my DIW to equal the number of ions in one gallon of Dasani water, that makes for a HUGE difference in your body.

Real World Light: As with any large company there are always those that disregard protocol and we have had several instances where workers have drank DIW. Every documented case resulted in diarrhea, stomach pain, cramps, and exhaustion. One did require medical attention (Saline IV) but they had repeated exposure.

Conclusion: It depends..... HAHA! It really does. DIW is generally separated into 3 classes of purity which are measured by conductivity. This is more of a ballpark guess of the total ion concentration. The ultra pure DIW often referred to MilliQ will "hurt" as in you will regret it. Class 3 DIW so long as your confident it doesn't contain amebas or something of the sort will not "hurt" you. Maybe a little sleepy and stiff. Dasani or other bottled waters have orders of magnitude more ions and have been treated with peroxide prior to deionization and are safe for daily consumption depending on the plastic. Most use HDPE but Dasani has a new bottle where they use sugar to make PET bottles, the process is new and still has some issues to work out and some have shown high levels of toxins during leach tests.

David Clayton
- Boise, Idaho, USA

August 2, 2014

Q. Is distilled bottled water in original container, from 1999, safe?

katie gutowski
- rossford, Ohio usa

December 21, 2014

A. Deionized water does have ions in it. pH is a measure of the concentration of hydroxide(OH-) and hydronium(H3O+) ions in the solution. pH is measured on a logarithmic scale. So if you had a pH of 9, you would have 1000 times more Hydroxide ions in the solution than hydronium ions. (9[OH-] vs 5[H3O+] = 4 times greater). That being said a solution of a pH of 7 has equal parts hydroxide and hydrogen ions in the water. It has much less overall ions (on the order of 0.00000001 mol/L for 7 vs a 9 ph solution having 0.0001 mol/L)

H3O + OH <=> 2H2O

The Le Chatelier's principle equation in this case. Ions will always be present in the solution due the equilibrium equation. If ions are taken out, the water shifts to the left on the equation and more ions are formed.

So, in regards the problems with pH detector, the level of ions are so low that it can cause erratic readings. Not that there are no ions in the solution.

I would venture to say that drinking deionized water won't due much damage to you if consumed in reasonable amounts. I wouldn't recommend drinking it myself, but I would not persuade someone from drinking it. As long as you are not experiencing any side effects which are listed as possibilities from the associated wikipedia page.

With regards to the coffee, it could be that the DI water is just not getting the added bad taste that may be present in tap water.


Troy Harinen
- Groton, Connecticut USA

January 12, 2015

! As a consumer of distilled water for over 5 years and as a health researcher with extensive research in water and its use in human consumption, I agree with Xuan Lu except for the saliva argument.

There is not enough saliva in the usual human's mouth to make that much difference unless you only consume a small mouthful and swirl it around in your mouth.

When drinking an 8 to 12 ounce glass of water, there is no time for your mouth to produce enough saliva to change the water as it flows past your tongue, inner cheeks and down your throat: it a biologically impossible scenario for your mouth to produce enough saliva to make any significant changes to the water flowing through your mouth - it is similar to the silly argument used by proponents of fluoridation saying that fluoridated water flowing past your teeth will benefit your teeth: it is a biologically irreconcilable and illogical proposition - your mouth provides necessary proteins and bacteria that begin the digestion process for whatever you put in it and swallow.

That being said, drinking distilled water can only be beneficial to your health - it is as pure a water as you can get and is immediately available to your bodily functions for using and processing - the first place it ends up in, your stomach, contains Hydrochloric acid (HCl), converts it immediately into an acidic fluid ready to be digested and properly used by your body - it does not have to be transformed, processed or cleaned for proper use by your body.

The apparent leeching of minerals from drinking distilled water occurs because drinking such water actually allows your body to assimilate any free floating cations and anions in your body - passing them through your urine and feces; if one gets an apparent bad reaction from drinking such pure water it is because the body is using that pure water to help eliminate bad fats, toxins and minerals from the body - if this occurs, one should moderate their drinking of such water and combine it with eating much fruits and vegetables that will help the body move these out of the body - one may find that while taking in a sauna and drinking distilled water produces very smelly sweat for the same reason since this is another elimination pathway, however, too much sweating under these conditions may produce rashes and skin blemishes of various kinds.

Tap water is by far the worst type of water to drink, other than untreated water, for reasons already covered by other commenters.

As to DI Water, as long as it contains only water and no treatment chemicals, it may very well be as healthy as distilled or RO Water as long as it has also been filtered or otherwise freed of any contaminants, parasites, bad bacteria and all impurities.

Richard Hudon
- Ottawa, ON, Canada

April 22, 2015

thumbs up signSo, with all this paranoia over the Osmötterdämmerung, would it solve all these various horses of the Apocalypse to just . . . sprinkle some salt into your drinking glass? *Drops mike.*

Brandon Carter
- Hollywood, Florida, USA

April 25, 2015

! My family and I have been drinking DI water for the past 3 years, and has not suffered any ill effects, blood work are always good, I buy my water at a health food store. Of all the comments I have read there doesn't seem to be anyone of authority on this matter.

Juanita Weekes
- Durham North Carolina USA

thumbs up signHi Juanita. I think the reason for the confusion is that, as mentioned, we have conflated so many different things together. In the first place, DI water is not the same thing as distilled water. In the second place, DI water that is sold in stores by the bottle has been tested and purified, and is a very different thing than the industrial DI water that people say poses contamination issues. In the third place, water with just some of the ions removed via a cation and anion deionizing system is a much less aggressive solvent than the ultra-purity DI water produced by mixed-bed deionizing, and used in integrated circuit manufacturing (as David told us, his DI water has 50,000X less ions in it than Dasani). I'm sure you're right that bottled DI water poses no health risks due specifically to its de-ionization ... but like any other products there might be lapses.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

July 3, 2015

Q. Does anybody possess or could address me to the results of a scientific study demonstrating pro or contra of drinking distilled water?

Anatoly Krutov
- Moscow, Russia

January 10, 2016

A. I am a physician, and read through this thread with some degree of amusement. We use sterile distilled water all the time at the hospital. Of course you can drink it! It doesn't have a lot of taste, but it is completely harmless. Deionized water is also used as a source for purified or purified sterile water, according to the United States Pharmacopoeia.

The reason that distilled, deionized, or tap water doesn't leach anything out of your body when you drink it is due to osmosis across a semi-permeable membrane, in this case the gut wall. All these forms of water are hypo-osmotic to body fluids and cell contents. But the ions (AKA salts) don't get pulled out from the body because they can't cross the gut wall; instead the water gets pulled in, or absorbed. Any ions present in the water you drink have to be actively pumped across the gut wall cell membranes, a process requiring energy expenditure to transport the ions against the osmotic gradient.

I suspect, as others have said in this thread, that you don't want to drink industrial deionized water due to the addition of non-ionic antiseptic agents which prevent the growth of bacteria and fungi.

Lane Peterson
- Olathe, Kansas, USA

June 11, 2016

Q. Hi everyone, could I add to this thread please? I have some 5 gal drums that contained deionised water for use in fork lift truck batteries. Can these be cleaned out in any way so that I can use them for drinking water while camping? The label on it says "this material must not be used for human or animal consumption or in products manufactured for human or animal consumption. This container must not be used or contaminated with any other material". I have 4 of them that I was going to use for changing the fluids in my truck, and thought I could use one for camping after cleaning. Would this be okay or should I steer clear? And advice either way would be most appreciated.

Mark Waters
- Cardiff, UK

October 24, 2017

A. Didn't read all of the thread, but on your submarine comment, you're right: on a submarine we make ultra pure water but then it's put into 2 potable tanks with controlled bacteria to make it drinkable.

Stephen Gallion
- Monson, Massachusetts USA

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