Introduction: How to Purify Water Using Iodine Tincture

Picture of How to Purify Water Using Iodine Tincture

When you're in the wilderness, you need clean water to drink -- but water sources in the wilderness can carry bacteria such as giardia. You don't want giardia, trust me, and trying to carry a few jugs of Poland Spring would be extremely heavy and inefficient. Luckily, there are a number of ways to purify water, and one of the simplest, cheapest, and most effective ways is to use iodine tincture.

Step 1: Supplies

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To complete this task, you'll need the following:

--Water bottle: A Nalgene (what I use here) or a metal water bottle will work best, but all you really need is any container that will hold water.

--Iodine Tincture Solution: You want Iodine Tincture with 2% Iodine and about 47% alcohol. Bottles of this solution should be available at your local drugstore and a 2 oz. bottle is usually $3 or less.

--An eyedropper: Counting the number of drops is the easiest way to keep track of how much you're using.

--A good water source: This can be a lake, a river, a stream, etc. If you have a choice of water sources, consider these two tips:

Clear water is better than cloudy water.
Flowing water is better than still water.

Remember, though, that even if the water looks extremely pure and clean, it should still be purified before drinking. Looks can be deceiving!

Step 2: Fill Your Bottle

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After finding a water source, you need to fill your bottle with water. To do this, position yourself close to the water source and tilt the bottle under the water. You want to collect water from near the surface, so don't just immerse the whole bottle in the water. Let the bottle fill up and remove it.

Examine your bottle of water to make sure there are not too many floating particles (called "floaties" in scientific terms). A couple of small floaties are fine, but too many large floaties can be dangerous. If this happens, you need to try filling up again. A way to solve this problem is to cover the mouth of the bottle with a bandanna or thin cloth that will allow water into the bottle but keep floaties out.

Step 3: Add the Iodine Tincture

Picture of Add the Iodine Tincture

Dip your eyedropper into the iodine tincture and squeeze up some of the liquid. Carefully position the eyedropper over the mouth of the bottle and add 5-10 drops per 32 fluid ounces (about 1 liter) of water. The exact number of drops is a personal choice (I can't make this decision for you) depending on the following factors:

The water source: if your source is a lake or some other still body of water, you want to add closer to 10 drops; if the source is flowing, you can add fewer.
The clarity of the water: you should add closer to 10 drops if the water is cloudy.
Your own aversion to the taste of iodine: some people hate the taste of iodine (it is a little bitter, and you will notice the taste in your purified water). If this is the case, you might want to add closer to 5 drops.

Personally, I'm a fan of 8 drops. If you are filling up a bottle or container that is not 32 fl. oz. or 1 liter, change your measurements accordingly. A 2 liter bottle will require twice the number of drops.

Step 4: Wait 5 Minutes

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After adding the iodine, you need to wait 5 minutes before you can continue. You can go for a quick hike, admire nature, play a game, or think up an idea for your next Instructable.

Step 5: Thread the Bottle

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After five minutes, you need to purify the mouth and rim of the bottle (which touched the original water source and which will touch your mouth). To do this, you need to "thread" the bottle. Turn the bottle upside down and slowly unscrew the top until you can see a ring of water appear around the inner rim. Once you see that ring of water, you know that the water with the iodine has touched the mouth of the bottle and disinfected it. Screw the top back on and flip the bottle right-side up.

A little water will probably leak out while threading, and that's not bad--it just ensures that you've fully threaded.

Step 6: Wait 30 Minutes, Then Enjoy!

Picture of Wait 30 Minutes, Then Enjoy!

The iodine needs time to completely purify the water. You need to wait 30 minutes before you can drink the water--plenty of time to finalize that idea for an Instructable.

After you have waited 30 minutes, your water is purified for drinking. Revel in the cool, clean taste of your iodine-infused water while you enjoy your wilderness adventure.


DonL68 (author)2017-09-09

Me? I'm doing charcoal filters ONLY!! KISS

tedsan (author)2010-09-21

tincture is poisonous, Lugols solution is not. Use Lugols. All of the other halogens, flourine, chlorine, and bromine are also poisonous and replace iodine (which is a necessary nutrient) in the body.

nnnoooiiissseee (author)tedsan2010-11-08

I agree. You may want to simply change Iodine Tincture Solution to 2.2% Lugol's solution. Otherwise, you may have someone who is deathly afraid of Iodine, flag your post and then keep posting over and over about how your instructable "may" kill someone or "may" cause monkeys to fly out of their butt.

Unless you have a very rare case of being allergic to Iodine, Lugol's is not only safe, but actually good for you when taken is reasonable amounts.

Using Lugol's is much healthier for you than chlorine is.

""For many years physicians used potassium iodide in doses starting at 1.5 to 3 gm and up to more than 10 GRAMS (not milligrams) a day, on and off, to treat bronchial asthma and chronic obstructive pulmonary disease with good results and surprisingly few side effects."" !!!

Please read the article yourself:

I sure am glad that the "deadly poisonous, and super duper highly toxic iodine" fear mongering is over now.

dude's before stating that something is poisonous how bout actually looking to see if it is.

Now i AM a chemist and looking up the MSDS it states the ld50 of Lugol's iodine AND tincture of iodine is 30 mg/kg! Why?? Because both Lugol's and tincture are just different ways of solubilising elemental iodine, which is poisonous but your body can hack a bit of it, same as chlorine.

Elemental iodine is very insoluble in water so it needs something to help it dissolve. Lugol's solutions uses a salt "KBr", while tincture uses ethanol and a lot less KBr, or NaBr. Your body can hack alot more ethanol than it can iodine.

This method that has been shown is technically sound, Just don't use two much iodine so you don't kill your liver.

macglobalus (author)paliaspip2017-07-02

It can not process industrial ethanol man!!!!!!! it will kill you

What do mean by "industrial ethanol"? Perhaps you are thinking of denatured alcohol? While denatured alcohol may be poisonous (depending on how it was denatured), it is very likely that the the ethanol in a tincture of iodine is NOT denatured. I say likely only because I don't know this for a fact but you can look at the ingredients on the label. If it says 5% ethanol it is not denatured. If it says 5% denatured alcohol it is. Furthermore, a few drops of 5% ethanol in a half gallon of water is totally safe, even for those who never drink.

ndjalva (author)xenoscientific2017-09-07

I qt of cheap will kill most anything in the qt of water. More fun than iodine

Bleach also works. Prepper school:

Place the water (filtered, if necessary) in a clean container. You can use coffee filters, or towels/shirts to filter the water prior to treating it with bleach. Add the amount of bleach according to the table below. Mix thoroughly and allow the water to stand for at least 30 minutes before using (60 minutes if the water is cloudy or very cold). Treating Water with a 5-6 Percent Liquid Chlorine Bleach Solution Volume of Water Bleach Solution to Add (Clear water) Bleach Solution to Add (Cloudy, Very Cold) 1 quart/1 liter 3 drops 5 drops 1/2 gallon/2 quarts/2 liters 5 drops 10 drops 1 gallon 1/8 teaspoon 1/4 teaspoon 5 gallons 1/2 teaspoon 1 teaspoon 10 gallons 1 teaspoon 2 teaspoons Purifying water with bleach is safe if you follow the proper guidelines and use the correct type of bleach. Only use Calcium Hypochlorite bleach, and avoid using bleaches that contain perfumes, clarifiers, dyes and other additives. Be sure to read the ingredients on the label.

Copyright © Read more at:

If you have a choice between Lugol's formula and some xyz brand pushing tainted Iodine, what are you reaching for? and yes, Alcohol is POISON to the body - elementary knowledge. So what if everyone chooses it to subdue their lives - what's that old folk name they call it .. choose your poison..referring to ALCOHOL. Do you know the function of mixing Iodine with Alcohol? Again, why use inferior when you can choose the best. And the body does not 'hack' iodine, it utilizes it. You are a bit mixed up with your logic.

Alcohol is less toxic than iodine. Look up the lethal doses. Sounds like you are on a bit of an iodine mission here. Just because you take iodine every day below the level of toxicity doesn't necessarily mean it is good for you or anybody else. The body does need a very very small amount, micrograms per day, but not milligrams per day. And no, I am not a troll for the pharmaceutical industry. (That any such person would be following this tread so somewhat laughable.)

It can't use elemental iodine, at all, actually.

TerryG71 (author)paliaspip2017-07-02

very well said


If you're replying to my post, maybe you should read it again. It's called irony.

I should have been more specific though because they're may be a few people around here who are actually dumb enough to put 10 GRAMS of Iodine in their bottle of water. You only need to use the recommended amount to purify water kids, no need to dump the entire bottle in there...

I was actually making a general statement considering all the different posts.
Potassium iodide isn't Lugol's though, just making a differentiation. Potassium iodide is used as a iodine supplement with an ld50 of 2g/kg. Not Lugols! Lugols is KBr + I2 dissolved in water and shouldn't be used as a supplement due to the free iodine, which is toxic

There is nothing toxic about lugols. Don't take my word for anything though. GOOGLE it. It would be illegal to sell lugols as an oral supplement if there was anything poisonous about it.

The same goes for vitamins. You should take one a day. They're good for you. If you try to eat the whole bottle in one sitting though, then YES, vitamins are poisonous.

So, trying to be constructive here, Lugol's has been used as an oral supplement in the past. The reason why it should not be anymore is because IT IS TOXIC. All tests on LD50 that you will find are shown for rats who have a very high tolerance, about 2 g/kg.

However they have done recent human studies and found as I mentioned before a LD50 of 30 mg/kg! Which is a heck of alot less than rats, and why they don't want people to use it, even though you are having a very diluted amount. Any lugol's MSDS within the last few years will state these values.

It is dangerous to say that something is not toxic just because you can buy it of the shelf. Warfarin (rat poison) can be bought as a blood thinner, even though it is extremely deadly. Likewise Lugols IS TOXIC, but can be used at low levels

"Lugol's has been used as an oral supplement in the past. The reason why it should not be anymore is because IT IS TOXIC."

And it STILL IS used as an oral supplement. If it were found to be "ToXiC" by any kind of REPUTABLE and CONCLUSIVE source then it would be ILLEGAL to SELL IT as an ORAL SUPPLEMENT.

"Lugols IS TOXIC, but can be used at low levels"

Everything IS TOXIC, but can be used at low levels.

And again (sighs) ANYTHING is TOXIC when used in large enough amounts.

I heard of this guy who went swimming IN PERFECTLY CLEAN WATER and he DIED of water poisoning! He drank SO MUCH of it (here it comes)... it KILLED HIM DEAD!

No more water for me! That stuff is ToXiC!

Here's some more links to different web sites ALL saying that it's perfectly FINE to use Lugol's solution to purify water.

So, what is the name of the guy who was "poisoned" by Lugol's solution? Exactly who is the "they" that you are referring to who conducted these tests? How many controlled tests did they conduct? WHO FUNDED THEIR RESEARCH? How much money is "the human" suing the company for, who tried to poison him with Lugol's solution?

And the best question of all... WHAT HAPPENED TO THAT DARNED RAT? Did he get a tummy ache? Maybe it made him turn into a pumpkin? Exactly what irreversible TOXIC reaction occurred which was so horrifying that it made "they" say:

"The reason why it should not be (used) anymore is because IT IS TOXIC."

Lugol's solution turned that poor rat into a ZOMBIE!!!

I've posted links to numerous places which ALL STATE that it is PERFECTLY SAFE TO USE LUGOL'S SOLUTION TO PURIFY WATER.


Except for the time some guy, in some lab (who probably worked for Pfizer or Bayer) PROVED that Lugol's solution is "toxic" by a test he preformed on ONE rat ...(who was also dying of terminal cancer and AIDS at the time of the test).

I am an environment, health and safety expert with experience architecting biochemical warfare agent abatement systems and other air, water and waste pollution controls for major aerospace, mining, working with industry associations and DARPA. The mixture of nascent iodine and potassium iodide comprising Lugol's Solution is not toxic to humans. It is necessary to replace the chlorine, fluorine and bromine that has keyed into every cell in your body; which, create a very toxic body condition! A therapeutic dosage of Lugol's solution is necessary for a long time (up to 1 year) to replace those halogens with iodine, which is an essential nutrient for humans. Seaweed in excess is an issue, as seaweed adsorbs metals including arsenic, of which one can receive too much. The modern medical community is now doing great work with iodine for highly deficient communities throughout North America. Do the research and get educated. All the best and respectfully,

Iodine can be used as long as it is the right solution I have been using it for yearsand I am fine

paliaspip sounds like he works for the medical white coat industry. Perhaps just brainwashed by it.

Yup, worry about iodine stains on you white coats and on your fingers, too, when preparing your own Lugol's solutions.

Dear eye..

Did you read paliaspip's post carefully?

M2aestro (author)nnnoooiiissseee2015-08-29

The subject of how much iodine in iodide form is pretty controversial, I have read, in Germany to this day, with some physicians believing that even iodized salt is not a good thing!

shadus (author)nnnoooiiissseee2011-06-12

I'll just add this-- I have heard of poisoning by tincture of iodine... when someone used the high potency solution instead of the low (It's about 4x stronger) and even then it was for an extended period of time.

Using even 4% tincture of iodine or lugols iodine is perfectly safe for a reasonable period of time as long as the person taking it isn't a complete moron and if they are a complete moron that is a self solving situation.

Chill out everyone, tincture or lugols both work fine and are both safe so long as you don't get stupid or try to live on it extended periods of time.

Given a choice between the two I would use Lugols 1% solution. That being said chlorine is a better solution than either for killing of cryptosporidium or giardia consistently and rapidly.

You use what you can in a pinch and most first aid kits have tincture of iodine in them for wound treatment so it's important to understand how to use it, because you'll likely have access to it even if fairly unprepared.

saumipan (author)paliaspip2015-08-27

LD50 studies are NOT performed on humans. What kind of chemist are you, again?

M2aestro (author)saumipan2015-08-29

Remember, too, that LD50 represents the dosage of 50% kill of the rabbits. Why the devil would lD50 even be germane to this discussion?

Lugol's could be very well toxic if used in dose that is non-sense. But in the logical method, it's a life saver and a healer. Your metaphor is amusing but is rather like a smoke screen and I'm not sure if you're just playing dumb or plain dumb. I have used Lugol's for 5 years every day at various doses with only positive effects that I have proof of . It's not a miracle cure, it's a sensible addition to human life.

jusup.wilkosz (author)paliaspip2014-12-21

Something is not necessarily toxic in low levels because it it toxic in high levels. The LD50 of vitamin C is 12 g/kg. Does that mean that vitamin C is toxic? No! The dose determines weather something is toxic or not. Even pure water is toxic when drunk in too large amounts in a short time. If you drink 8 liters of water within an hour you will die because of water intoxication.

cunningfellow (author)paliaspip2011-04-22

Hi Paliaspip. Not questioning whether you are a chemist or not, but I do need to set the record straight. Lugol's does NOT contain KBr and I2. Lugol's contains KI and I2.

The history of Lugol's is that it was invented by a French physician, Dr Jean Lugol in the 1820's for a variety of uses, includin as a dietary iodine supplement. Potassium Iodide (KI) is now considered to be safer than Lugol's. Sure, elemental iodine is poisonous in large doses, for example 2 to 3g is considered dangerous to life.

Consider: in a 50ml bottle of Tincture of Iodine, with 2% elemental iodine, half of which is I2 and half of which is KI, then (ignoring the weight of the K for this exercise) we have around 1.3% K2, or about 15 mg - around 1/200 of the lower of the dangerous doses. The lowest lethal dose (LDL) is 28mg per kg of body weight. Not 28mg - 28mg PER KILO of body weight.

If you were to drink 200 x 50ml bottles of tincture of iodine, then yes, you would be poisoned. As this article is about using 5 to 10 drops of this solution, the only possible danger would be to somebody with an iodine allergy.

I take an 'over the counter' tablet from Wells Pharmaceuticals called Cydiodine Buccal tablets for sore throats. Each tablet contains 1.5mg of elemental iodine, with the advice that not more than 5 tablets to be taken in one day.

The lowest lethal dose (LDL) is 28mg per kg of body weight.

The sky may well be falling, but I'll take my chances with the iodine, and not with the microorganisms!

paliaspip (author)cunningfellow2011-04-26

I use iodine as my main method of purifying water. I rate iodine as the best method for hikers etc.
I stand corrected with KI, my bad for the slip up. Truth be told it will take a bit to kill yourself with iodine. The reason I try to get people to exercise caution with how much iodine they add is because that it takes a big tole on you kidneys. In the "Australian Air force Survival School" they only allow the use of iodine for purification for three days only. After that, it takes to much of a toll on your kidneys.
Excess iodine is not advisable.

MarkB82 (author)paliaspip2015-08-27

Agreed! I perfer boiling, then add a few drops of lemon flavor. I really don't like iodine flavored ANYTHING. Small block of solid fuel does wonders quickly boiling water!

rustyfox (author)paliaspip2015-04-25

Slight correction to that - probaly a typo: Lugol's uses KI, not KBr. Other than that, totally agree with you! Too many panic merchants out there wanting to tell everybody that everything is dangerous!! Tincture and Lugol's both contain elemental Iodine and Potassium Iodide:

USP Tincture of Iodine is defined in the U.S. National Formulary
(NF) as containing in each 100 mL, 1.8 to 2.2 grams of elemental iodine,
and 2.1 to 2.6 grams of sodium iodide. Alcohol is 50 ml and the balance
is purified water.

The 5% solution consists of 5% (wt/v) elemental iodine and 10% (wt/v) potassium iodide mixed in distilled water and has a total iodine content of 126.5 mg/mL.

hinge (author)paliaspip2011-04-11

@paliaspip I always thought that Lugol's solution involved NaJ possibly KJ(sodium/potassium iodides).Maybe there's some other Lugol's composition I'm not aware of

anax22 (author)paliaspip2011-04-10

sorry Mr.chemist i happen to be a bio-tech engineer not complaining abut any thing but giardia is no bacteria its a deadly parasitic protozoa and it is not really sensitive to to iodine compounds not that much that it will get killed so try simply boiling the water or using chloride water disinfection tablets its much effective than that i guess always peace out

paliaspip (author)anax222011-04-10 your research.

Iodine does inactivate giardia. However it does not inactivate Cryptosporidium cysts, same with chlorine. As far as chlorine goes, it is less favorable to use mainly because of its usable lifespan, 3 days compared with 3 months for iodine, which is the main consideration out bush. But it is faster at killing certain organisms (E. coli). Boiling is more effective than both.

Below is a scientific article that you can look at.

"Efficacy of iodine water purification tablets against Cryptosporidium oocysts and Giardia cysts"

Also for those who use Vitamin C to remove the taste of iodine. Your breakdown product is Hydrogen iodide which has a ld50 of 30 mg/kg, which is just as toxic as the iodine. So still be careful with how much iodine you add!

Doctor Chemist

anax22 (author)paliaspip2011-04-11

will yeh it have an inhibitor effect on it but still giardia resist iodine also chloride but chloride will form stronger bond with glycolipids in the cyst causing longer inhibitor effect that can tolerate dilution (in digestive tract) so as to pass safely and case no infection will u can use a mixture of reagents to clean water it would be just better always peace out

paliaspip (author)anax222011-04-11

So do you know the difference between inactivate and inhibit?? I'm not sure you do. If you even glanced at that article i told you about you would see that what you just spouted is in direct contradiction to it. I know who i'll be trusting

hinge (author)anax222011-04-11

@anax Sir,it is chlorine not chloride tablets.Any chloride is zero effective against any bacteria

anax22 (author)hinge2011-04-11

sorry i an no chemist but u get the point :D

hinge (author)paliaspip2011-04-11

@paliaspip Could you elaborate on the subject of KBr(potassium bromide) or Na Br(sodium bromide) being present in Lugol's solution?Why would anybody introduce bromide to Lugol's solution?

paliaspip (author)hinge2011-04-11

So elemental iodine or free iodine is what gives Lugols, tincture, providone or tetraglycine hydroperiodide its ability to bind and kill pathogens. The problem with normal iodine though is that it is not soluble in water. So the above methods are different ways to solubilise iodine.

Lugols uses twice the amount of an inert salt KBr which is quite soluble in water. The iodine forms a triiodie bond around it, and hence makes it soluble in water and more usable.

Tincture uses half the weight of KBr or NaBr than iodine, but dissolves it up in ethanol (alcohol). This can than be added to water as per instructable above.

studleylee (author)paliaspip2011-04-10

Thanks for this glimmer of sanity. Cody L. Uses similar methods in classes he teaches about 45minuts away from here. He's a friend of a friend

TerryG71 (author)nnnoooiiissseee2017-07-02

Military has been using Iodine for years its not dangerous if used carefully.

Many members of my family are allergic to iodine. Shrimp in a salad put my brother in the hospital. He stopped breathing on the way to the hospital.

It took my late Mom years to find out she was allergic to iodine. She loved shrimp, but would get a bad headache and feel ill after eating them, later found out it was iodine. Never knew anyone else allergic to it.

Lew Rockwells link is not live anymore.

Great link - something people should spend time to explore. real lugol's formula is a key to survival of the fittest. Not the garbage sold on those shock jock radio shows.

While iodine is fine to disinfect water, that article is BS. It relies almost entirely on the fallacy of correlation implying causation, and it is from which is never trustworthy.

Your asthma anecdote also seems to rely entirely on the fallacy of argument from authority. And you say it as somehow doctors, especially those in the past, are infallible people. Doctors also used to prescribe blood letting and leeches.

Please post some double-blind well-controlled studies from an academic institution or don't bother posting, because anything outside of that is pure conjecture.

cunningfellow (author)AutumnJazz2011-04-22

"Please post some double-blind well-controlled studies from an academic institution or don't bother posting, because anything outside of that is pure conjecture."

It is for reasons such as this that Tincture of Iodine has been removed from sale in pharmacies in Australia - because there is no 'proof' that it kills anything. Unless there are millions of dollars in profits to be made by a pharmaceutical company, nobody will finance such tests. The same applies to calamine lotion, gentian violet and acriflavine - all of which are known by the millions of people who have used them to be effective, but because no 'scientist' has 'said so', they are deemed ineffective.

Absence of evidence is NOT evidence of absence. And abscence of evidence of efficacy is NOT evidence of inefficacy.

Some people are actually capable of making their own decisions, without needing the approval of some 'wizard' who is in fact, just another person.

hedys (author)cunningfellow2014-08-14

not sure how to follow the arguments re effective or ineffective/lugols v tincture.... however, I did buy Iodine Tincture from a Sydney pharmacy without any problems. It was not hidden under wraps but in plain sight on shelves. Thus "Tincture of Iodine has been removed from sale in pharmacies in Australia
- because there is no 'proof' that it kills anything." seems not to be factual.

Lew certainly seems like a nutter, he's like some strange eugenic compilation of Glenn Beck and Rush Limbaugh..

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