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Thread: The forgotten alternative sanitizer for pools and spas that was extensively studied i

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    Red face The forgotten alternative sanitizer for pools and spas that was extensively studied i

    There were a number of studies done at Standard University, the University of Maryland, the University of Florida, Gainesville Municipal and Florida motel pools. All of these studies showed the sanitizer to be an effective at killing bacteria based on laboratory test results. Yet the sanitizer is not used today. What was it?

    Iodine. Iodine is a halogen. Halogens make up a column on the periodic table of chemical elements. All of the elements in a column have similar properties. Some of the halogens are: fluorine, chlorine, bromine and iodine. Chlorine and bromine are sanitizers heavily used for pools and spas and are toxic. In fact, chlorine was used as war gas in World War I. The concentrations in the pool will not kill you but they do account for red eye, skin irritations, bleached hair, bleached bathing suits, and other potential health problems. Iodine is actually an essential nutrient and causes none of the reactions that Chlorine does and in fact I was able to bath in my hot tub with iodine for hours without even wrinkled fingers.

    Since many people are deficient in iodine you can potentially get health benefits from its use.

    Iodine is more expensive per pound than chlorine, but since it is a solid at room temperature instead of a gas, it lasts longer. The chlorine you add to most pools are compounds. The compounds break down and release chlorine as gas. Because of this iodine actually lasts longer and may be cheaper to use. The studies in the 70s came to this conclusion but pricing has changed considerably since then.

    Iodine is commonly introduced into water as potassium iodide which is readily soluble. Something must be used to break it down into potassium and iodine. Ozone, which is extensively used in pools in Europe and hot tubs in the US is very effective at breaking down potassium iodide and oxidizing organic matter in pools and hot tubs. However, ozone is not very stable so most health departments want at least a low level of residual sanitizer. Also Iodine does not handle organic matter but ozone does. They make a great combination. Adding, a residual sanitizer also means that the ozonator does not have to be run 24 hours a day. Iodine makes a wonderful residual sanitizer. I have been using it with ozone in my hot tub for about a year with no health problems or algae problems either even though iodine is not supposed to be an algaecide. In fact, I left my hot tube at 106 degrees for several month with the ozone off, and the aeration off just circulating the water through the filter and heat exchanger. I thought I was going to have a green mess but the water stayed clear! I highly recommend it. I also had some calcium bentonite clay, a Nature2 Mineral Cartridge and epsom salts in the hot tub.

    Iodine is an approved sanitizer for food establishments. “Iodine Concentration: 12.5 to 25 ppm
    Iodine compounds or iodophors are fast-acting and effective against all bacteria. They are relatively nontoxic, non-irritating to skin, and stable. Iodophor solutions may stain porous surfaces and some plastics.” Southern Nevada Health District. However in the concentrations mentioned the water will turn brown and could stain things but these concentrations are for rapid sanitizing equipment in a food establishment not swimming pools.

    “With iodine as metallic iodine, 2.0 ppm is necessary to provide a result equivalent to the 0.6 ppm of available chlorine control with both E. coli and S. faecalis.” Comparison of Chlorine, Bromine, and Iodine as Disinfectants for Swimming Pool Water
    T. A. Koski, L. S. Stuart, and L. F. Ortenzio

    Based on the above about 3 ppm iodine should be enough when used with ozone.

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    The problem is that iodine is a sanitizer, and not an oxidizer. In a pool you need both. You will still need to add something to cover both.

    Richard chem geek had this to say in a previous thread

    Quote Originally Posted by chem geek View Post
    The chemistry of chlorine and bromine are such that they are very effective sanitizers, and they are oxidizers to boot so you get a 2-fer.

    Iodine is basically an effective sanitizer, but it does not control algae and it does not effectively oxidize organic matter.
    i had to edit this out of a much larger reply, but you can search on iodine here and see that it has been discussed before.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    RE: "The problem is that iodine is a sanitizer, and not an oxidizer. In a pool you need both. You will still need to add something to cover both."

    Yes it is true that Iodine is not an oxidizer. I am not suggesting it as the primary sanitizer but as the secondary or residual sanitizer used with Ozone. Ozone, O3 is an excellent oxidizer.

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Something I forgot to mention: If you add ozone 24 hours a day to a heat pool or hot tub the air and ozone that are sucked into the water cool it down quite a bit particularly in winter. (I know. I tried it.) So a good residual sanitizer is vital for hot tubes and heated pools. Again, what I use potassium iodide.

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Quote Originally Posted by Bernie301 View Post
    Chlorine and bromine are sanitizers heavily used for pools and spas and are toxic. In fact, chlorine was used as war gas in World War I. The concentrations in the pool will not kill you but they do account for red eye, skin irritations, bleached hair, bleached bathing suits, and other potential health problems. Iodine is actually an essential nutrient and causes none of the reactions that Chlorine does and in fact I was able to bath in my hot tub with iodine for hours without even wrinkled fingers.

    Since many people are deficient in iodine you can potentially get health benefits from its use.
    :
    Iodine is commonly introduced into water as potassium iodide which is readily soluble. Something must be used to break it down into potassium and iodine. Ozone, which is extensively used in pools in Europe and hot tubs in the US is very effective at breaking down potassium iodide and oxidizing organic matter in pools and hot tubs. However, ozone is not very stable so most health departments want at least a low level of residual sanitizer. Also Iodine does not handle organic matter but ozone does. They make a great combination. Adding, a residual sanitizer also means that the ozonator does not have to be run 24 hours a day. Iodine makes a wonderful residual sanitizer. I have been using it with ozone in my hot tub for about a year with no health problems or algae problems either even though iodine is not supposed to be an algaecide. In fact, I left my hot tube at 106 degrees for several month with the ozone off, and the aeration off just circulating the water through the filter and heat exchanger. I thought I was going to have a green mess but the water stayed clear! I highly recommend it. I also had some calcium bentonite clay, a Nature2 Mineral Cartridge and epsom salts in the hot tub.
    "Chlorine used as war gas in World War I." That is completely irrelevant, don't you think? We deal in facts here, not scare tactics through the presentation of deceitful and misleading information. Even at hot spa temperatures, during a soak with a typical 2 ppm FC with 40 ppm CYA (people usually soak with lower chlorine levels and then add chlorine to oxidize bather waste after their soak), the amount of hypochlorous acid in the water (at pH 7.5 and 104ºF) is around 0.1 ppm while the amount of aqueous molecular chlorine in equilibrium is only 0.02 ppt (that's parts-per-trillion) so chlorine gas is not an issue at all.

    As for red eye, that does not come from chlorinated water especially when Cyanuric Acid (CYA) is used. It comes from low salt levels due to osmosis that has water enter into the eye and causes pressure and irritation. See this paper that describes that the salinity of the water is the primary factor in eye irritation (except for high chloramine levels). Your epsom salts have increased the salinity of the water since the magnesium sulfate increases the salt level (and though it's sulfate and not chloride, that doesn't matter for net osmotic pressure which is the relevant factor in eye irritation).

    As for bleached swimsuits and hair, this can be largely mitigated through proper use of CYA that significantly lowers the active chlorine level. It is true, though, that since iodine is such a poor oxidizer that it does not have much effect on swimsuits, skin, and hair.

    The disinfection by-products from iodine are more toxic than from chlorine and bromine. Iodine has been used for some portable drinking water treatment but chlorine dioxide (from Dichlor and sodium chlorite) is a preferred approach due to fewer disinfection by-products and for inactivation of Cryptosporidium parvum. Even comparing iodine to chlorine as done in this paper demonstrates the following:

    Based upon previous measurements of chronic mammalian cell cytotoxicity for the individual THMs, consumers of two waters treated with iodine tincture would receive the same THM-associated cytotoxic exposure in 4-19 days as a consumer of the same waters treated with a 6-fold higher dose of chlorine over 1 year.
    In the same way that brominated THMs are more toxic than the chlorinated ones, iodinated THMs are even more toxic so are generally to be avoided and the same is true for other DBPs. As noted in this fact sheet:

    I-DBPs are highly toxic to cells, and one I-DBP (iodoacetic acid) is greater than 250 times more toxic to cells than a regulated DBP (chloroacetic acid) (Plewa and Wagner 2009).
    This paper goes into more detail about the higher toxicity of iodinated disinfection by-products:

    iodine-containing DBPs were found (in general) to be the most toxic and chlorinated species the least, with bromine-containing DBPs of intermediate toxicity.
    So your assertion of chlorine and bromine being toxic is wrong -- it's the disinfection by-products that are the problem. And your implication that chlorine and bromine are more toxic than iodine is wrong since again one must look at the disinfection by-products and the order of toxicity for those are the DBPs from iodine > bromine > chlorine.

    Iodine will not control algae growth while ozone in the circulation path and not leaving a residual in the bulk water will not prevent algae from growing on surfaces. This is more of an issue with pools than with spas since algae is not commonly seen in covered spas due to the lack of sunlight and the much hotter temperatures. That's why you didn't see algae in your spa -- hardly anyone does so long as it's normally covered and the water at least on occasion very hot.

    As for wrinkled fingers, that has nothing to do with chlorine or iodine. One gets wrinkled fingers in bath water regardless of whether chlorine or monochoramine or nothing is used. [EDIT] At first I incorrectly wrote that the skin wrinkling was from osmosis, but according to this article it is wrong. [END-EDIT] There might still be a reduced effect from saltier water from the epsom salts, but that's just speculation.
    Ozone will rapidly oxidize iodide to iodine so one must carefully manage/control the iodide bank and not overdose.

    So on balance, the issue is mostly about disinfection by-products so if one were using chlorine instead of bromine to try and minimize those, then most certainly one would not want to use iodine instead. If one doesn't care about minimizing the DBPs, then iodine does have the benefit you describe of not being a strong oxidizer so being easier on swimsuits, skin, and hair. There are other non-chlorine alternatives that do not have the disinfection by-product issues of any of the halogens and are EPA-approved for spas, namely Nature2 with non-chlorine shock (MPS), and Baquacil/biguanide/PHMB with hydrogen peroxide. An alternative not approved by the EPA for pools or spas but that is used for drinking water decontamination is chlorine dioxide (e.g. Katadyn Micropur MP1) and it produces fewer disinfection by-products.

    So let's sum up:
    • Your use of epsom salts, not iodine, is the reason for lower eye irritation (note that the high salt level increases conductivity of the water that increases the risk of metal corrosion).
    • The disinfection by-products from iodine are more toxic than those from bromine and those are more toxic than those from chlorine.
    • Iodine is not a good oxidizer so will be less harsh on swimsuits, skin, and hair than chlorine or bromine (however, chlorine is significantly moderated in its strength in the presence of CYA).
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    "Chlorine used as war gas in World War I." That is completely irrelevant,...

    Sadly 10 deep breaths of chlorine at a concentration of 10% is fatal. Chlorine
    reacts the same way to the organic matter in your lungs as it does to organic particles in your pool.

    Yes this is 100,000 ppm, however by storing chlorine without adequate ventilation or
    indiscriminately adding it one can achieve high enough of a dose to land you in the hospital. I found such stories on the internet. Does much smaller dosages improve the health of your skin? Do you really want to bathe in it?

    Oxygen on the other hand is an element you can not live without and is 20.95% of the air you breath. Just by pumping enough air through a body of water you could probably oxidize the organic matter in it. For a hot tub this is not workable because it would cool down the hot tub except on extremely hot days.

    Ozone (O3) can be used instead. First Ozone is very unstable and breaks down rapidly into O2 and O1. This make high concentrations of it hard to build up. The O1 rapidly oxidizes organic matter and is extremely effective at killing bacteria, better than chlorine.

    When you use chlorine to oxidize organic matter you generate chloramines. These are toxic and you can avoid this by using Ozone as your primary sanitizer.

    Because Ozone is so unstable all parts of a pool or hot tub might not be sanitized. Accordingly a secondary residual sanitizer is recommended. A secondary residual sanitizer also means the Ozone does not have to be injected all the time.

    Iodine can be used as the secondary residual sanitizer. Iodine does not react to the organic matter in your pool this is actually a benefit because it also does not react destructively to your body. Your body actually needs iodine in small quantities. Iodine is very effective at killing bacteria.
    Iodine has other advantages it does not change the PH of the water and it is very stable so you rarely have to add it. Maintenance becomes much easier.


    Chem Geeks contention that the disinfection by-products from iodine are more toxic than from chlorine and bromine are simply not true.

    First all the studies he sites are in regard to drinking water. Are you drinking the water in your pool or hut tub?

    But there is more problems with the conclusion he draws from the studies he sites First study Comparison of byproduct formation in waters treated with chlorine and “iodine: relevance to point-of-use treatment”.is referring iodine tincture. This is iodine and alcohol and you might have used it treat cuts. However, I was talking about Potassium Iodide which has no alcohol. Thus this study is not relevant.

    Next reference is a FACT Sheet from the Water Research Foundation. This study is again talking about drinking water treatment and the Disinfection by Products created with chlorine or chloramine. So this Fact Sheet is actually a condemnation of chlorine. Or perhaps we should filter all iodine out of drinking water so the population can have more health problems due to iodine deficiencies. For drinking water this is absurd but such solutions have been suggested for chlorinated pools.

    The next paper has similar problems. The specified disinfection by products sited are created by chlorine. Since the body needs iodine it seems likely that toxic compounds created with iodine might get more rapidly assimilated into the body and thus be more toxic. But, that is just speculation. Why create them?

    In several studies of pools where iodine was added and chlorine was reduced or eliminated less eye irritation was the thing most commented on by the swimmers. Since chlorine reacts to organic matter how could it NOT cause eye irritation?

    Most people in the US are deficient in iodine. In Japan due to the consumption of seaweed and fish their intake of iodine is considerably higher and they have historically lived longer. So adding iodine to your pool can have a positive effect on your health, my dry skin went away and returned when my hot tub broke and I stopped using it.

    Also chem geek speculation that the fact that my fingers stopped wrinkling was due to epson salts is empirically not true. I soaked in a tub of unfiltered tap water (containing chloramine) and a high levels of epsom salts and my fingers wrinkled.

    In short you can add chlorine and then try to mitigate its effect with Cyanuric Acid and then balance your PH and due to evaporation regularly repeat. to Or you can use ozone and iodine and rarely add some iodine. For pools you will probably also have to add an algaecide. You will probably experience some health benefits.

    Ozone is injected in a pool by creating a small bypass line around the filter. The pressure difference caused by the filter will ensure water flows through the bypass line and a venturi tube causes the ozone to be sucked into the water. The Ozone generator is hooked up in parallel with the pump so it only runs when the pump is running. If by some accident the ozone generator ran when the water was not running a high concentration of Ozone could build up but you can smell it easily.

    Most hot tubs in the US come with an ozone generator or they already have the venturi tube set up for easy installation.

    Also there was a product approved by the EPA called Clearodine – A quality outdoor pool purifier. It contained 4% potassium iodide.

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    I could get all whipped up about the complete garbage in that response but I won't. I'll just dump a quote and be gone.

    Reason is not automatic. Those who deny it cannot be conquered by it.



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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Quote Originally Posted by Bernie301 View Post
    Sadly 10 deep breaths of chlorine at a concentration of 10% is fatal. Chlorine
    reacts the same way to the organic matter in your lungs as it does to organic particles in your pool.
    Did you read what I wrote about the ACTUAL concentrations of chlorine gas from a swimming pool at 0.02 ppt (parts-per-trillion)? So at least for the swimming pool water it's an irrelevant discussion.

    Quote Originally Posted by Bernie301 View Post
    Yes this is 100,000 ppm, however by storing chlorine without adequate ventilation or
    indiscriminately adding it one can achieve high enough of a dose to land you in the hospital. I found such stories on the internet. Does much smaller dosages improve the health of your skin? Do you really want to bathe in it?
    OK, so now you are talking about concentrated chlorine product. So let's look at that factually rather than make incorrect assumptions that you have been doing. 8.25% (weight % sodium hypochlorite) bleach is 61,763 ppm while 12.5% (Trade % so volume % available chlorine) chlorinating liquid is 125,000 ppm. Let's look at the latter. The pH is 12.5 so the hypochlorite ion concentration dominates at 1.76 M while the hypochorous acid concentration at this pH is only 1.07x10-5 M which is 0.76 mg/L (ppm). The chlorine gas concentration is 5.9x10-15 M which is 0.42 ppt (parts-per-trillion). So what you are mostly smelling from concentrated bleach or chlorinating liquid is hypochlorous acid and hypochlorite ion (yes, some amount of charged ions can escape as gas or in water vapor though it's limited due to their charge). You apparently didn't consider the pH when you leaped to the assumptions that high concentrations of sodium hypochlorite would lead to high concentrations of chlorine gas -- a false assumption as you can now plainly see. You can use my Pool Equations spreadsheet to make these kinds of calculations (or use a standard chemical equilibrium package such as CHEMEQ, MINEQL+, etc.).

    Why don't you explicitly link to "such stories on the internet"? I've looked and find chlorine gas incidents such as this one from a tank that had chlorine gas and this one where a worker mixed sodium hypochlorite with acid producing chlorine gas. Of course, you'd better read the details of whatever incidents you have seen to make sure they are realistic with what would occur when people chlorinate their pools. You should not mix concentrated chemicals together and do not mix chlorinating liquid or bleach with acid. There are all sorts of household chemicals that would produce dangerous results if mixed together so what exactly is your point?

    If one left an OPEN container of chlorine bleach in an enclosed area then one could build up mostly hypochlorous acid gas, but far worse is having Trichlor tabs in an enclosed area since they are acidic and do produce not only more chlorine gas but more nitrogen trichloride that is very irritating. Even opening a large container of such tabs caused one death from fumes and is one reason why individual Trichlor tabs are wrapped when in large containers.

    Quote Originally Posted by Bernie301 View Post
    Oxygen on the other hand is an element you can not live without and is 20.95% of the air you breath. Just by pumping enough air through a body of water you could probably oxidize the organic matter in it. For a hot tub this is not workable because it would cool down the hot tub except on extremely hot days.
    What in the world are you talking about? Oxygen does not rapidly oxidize organic matter. If it did, your own body would be oxidized right now. In fact, you are very slowly getting oxidized by the oxygen in air, but while this is thermodynamically favorable, the activation energy hurdle is high so the reaction rate is fortunately very slow unless temperatures are significantly elevated. That is, to have oxygen oxidize organic matter rapidly you have to burn it (e.g. incineration, cremation). Since your proposal of putting oxygen in water to oxidize organic matter is simply not true, it is clear that you do not understand chemistry yet are making arguments promoting an alternative sanitizer.

    Quote Originally Posted by Bernie301 View Post
    Ozone (O3) can be used instead. First Ozone is very unstable and breaks down rapidly into O2 and O1. This make high concentrations of it hard to build up. The O1 rapidly oxidizes organic matter and is extremely effective at killing bacteria, better than chlorine.
    Again, you have half-truths here. I suggest you read Chemistries of Ozone for Municipal Pool and Spa Water Treatment where you will find that ozone itself (O3) is the primary disinfectant and when ozone breaks down it forms (among other things) hydroxyl radicals and that these are the most powerful oxidizers but are very short-lived. To disinfect, the chemical is most effective if it enters into the cell to disrupt cell functions including those related to reproduction. This won't happen with some radicals that are too short-lived so requires a chemical such as ozone that lasts long enough, which it does since its half-life is roughly 15 minutes. The ozone itself is able to oxidize certain organics in the cell to directly disrupt its ability to reproduce, similar to how chlorine operates though the specific chemical sites that are attacked may be different.

    Also, look at the reaction rates in this paper that effectively show VERY rapid reaction of ozone with hypoiodous acid (and hypoiodite ion but this isn't present in significant quantities at pool/spa pH) so using iodide in a spa with ozone will have the ozone produce iodine which reacts with water to produce hypoiodous acid and is then rapidly oxidized by ozone to iodate (IO3-). So using ozone will result in fewer iodinated by-products simply because it will use up the iodide in your spa. However, if you try and maintain a constant iodine-based disinfection level in your spa, then the rate of iodinated organic production will remain the same, but this means essentially adding iodide to your spa before every soak because the ozone that runs in between soaks will completely convert all the iodide to iodate. Did you know that? You cannot maintain a residual of disinfecting iodine in an spa with an ozonator!

    Quote Originally Posted by Bernie301 View Post
    When you use chlorine to oxidize organic matter you generate chloramines. These are toxic and you can avoid this by using Ozone as your primary sanitizer.
    This is true, but in order to have ozone retain a residual in the water that is effective for disinfection, it has the risk of outgassing and ozone is a lung irritant and oxidizes your airways. Because of this, ozone is regulated by the EPA as an air contaminant and is why it is not used as a bulk-water disinfectant. It also doesn't last so maintaining its level can become cost-prohibitive. Also, the outgassing will degrade hot tub covers much more rapidly than chlorine outgassing (when CYA is used).

    So ozone is great as a supplemental oxidizer and supplemental disinfectant in the circulation path, but not as a primary bulk-water disinfectant. Because ozone reacts with chlorine, it is best used in residential spas that are used every day or two since the ozone oxidizes bather waste letting you use less chlorine for that purpose and therefore producing fewer chlorinated disinfection by-products. However, if the spa is not used regularly, then the ozone breakdown of chlorine results in a higher chlorine demand in between soaks.

    Quote Originally Posted by Bernie301 View Post
    Iodine can be used as the secondary residual sanitizer. Iodine does not react to the organic matter in your pool this is actually a benefit because it also does not react destructively to your body. Your body actually needs iodine in small quantities. Iodine is very effective at killing bacteria.
    Iodide that is oxidized to become iodine is then partially hydrolyzed to become hypoiodous acid but at pool/spa pH the equilibrium is more towards iodine (I2) though both are present. It is true that hypoiodous acid is not as reactive as hypochlorous acid or hypobromous acid with regard to oxidation. However, it IS still reactive with some organic materials to produce more toxic iodinated organics as described in this presentation. You are confusing oxidation from the far easier substitution reactions and it is these substitution reactions that produce the worst by-products.

    This paper describes the formation of iodinated trihalomethane. As described in this study the recommendation is to use ozone first, but in the case of both bromine and iodine this is due to a combination of the ozone oxidizing the organics first and converting the bromide and iodide to bromine and iodine and then to bromate and iodate so that subsequent chlorination does not produce bromine and iodine again. In other words, ozone works because it effectively removes the iodide by oxidizing it to iodate as I described earlier. This thesis summarizes many of the issues using different oxidizers in the presence of iodide. This paper describes I-THM formation where the iodine is created from chlorine dioxide, but again how the iodine is formed is not the issue here -- it's whether iodine (and hypoiodous acid in equilibrium) create iodinated trihalomethanes and other iodinated organics.

    Iodine also participates as a catalyst in many chemical reactions as described in this paper.

    Let's look further at what is now known about the vastly greater toxicity of iodinated disinfection by-products compared to brominated and chlorinated ones. See this presentation (from this talk but the original link is no good so I put up the presentation I had downloaded earlier) for an outstanding analysis of the issues. Take a look at the graphs showing the far greater cytotoxicity and genotoxicity from iodine compared to bromine and chlorine. They sum up the "Comparative in vitro Toxicology of Iodo-DBPs" this way:

    Cytotoxicity and genotoxicity indices were calculated for 18 iodinated, brominated, or chlorinated haloacetic acids, haloacetamides, acetonitriles or THMs.

    When this balanced design of DBPs was analyzed, the iodinated DBPs were substantially more toxic than their brominated or chlorinated analogues.
    Also, read this paper that says the following (consistent with all other papers on this subject):

    Although the formation of brominated DBPs has been studied for many decades, research on iodinated DBP formation has been an emerging area of concern. Iodide can react with ozone, chlorine, chloramines or chlorine dioxide to first form hypoiodous acid (HOI) (Bichsel & von Gunten 2000; Hua & Reckhow 2006). Ozone or chlorine can then further react with HOI to form iodate, which acts as a sink for the iodide. Alternatively, HOI can react with NOM to form iodinated DBPs. The yield of iodinated DBPs generally follows the order: chloramines (NH2Cl) > chlorine dioxide (ClO2) > chlorine (Cl2) ≫ ozone (O3).
    Iodine most certainly reacts with Natural Organic Matter (NOM) via substitution reactions and forms the most dangerous disinfection by-products. The iodinated by-products are a concern in medical imaging, and papers on drinking water are consistent with this one that says "Iodinated disinfection byproducts (DBPs) are generally more toxic than their chlorinated and brominated analogues."

    Quote Originally Posted by Bernie301 View Post
    Iodine has other advantages it does not change the PH of the water and it is very stable so you rarely have to add it. Maintenance becomes much easier.
    Ignoring pH effects from the creation of iodine from iodide since this depends on what is used for such oxidation, the hydrolysis of iodine to hypoiodous acid is acidic in the same way that chlorine gas to produce hypochlorous acid is acidic.

    I2 + H2O ---> HOI + H+ + I-
    Iodine + Water ---> Hypoiodous Acid + Hydrogen Ion (i.e. acid) + Iodide Ion

    Furthermore, if ozone oxidizes hypoiodous acid to produce iodate, this creates further acidity.

    2O3 + HOI ---> 2O2 + H+ + IO3-
    Ozone + Hypoiodous Acid ---> Oxygen + Hydrogen Ion (i.e. acid) + Iodate Ion

    However, it is true that this acidity will balance the rise in pH from carbon dioxide outgassing so with proper TA adjustment one can have relatively stable pH with a dropping TA over time. In fact, the net effect from ozone will lower TA by around 8 ppm for every 10 ppm iodide converted to iodate. So baking soda would need to be added until the iodide was depleted. You might actually be thinking that you have iodine left in the spa when in fact the ozone has converted all the iodide to iodate. While pH and TA may be stable at that point, you don't actually have any residual disinfectant in your spa (when the ozonator is off).

    Quote Originally Posted by Bernie301 View Post
    Chem Geeks contention that the disinfection by-products from iodine are more toxic than from chlorine and bromine are simply not true.

    First all the studies he sites are in regard to drinking water. Are you drinking the water in your pool or hut tub?
    The studies I referred to were scientific studies analyzing iodine's reaction with various chemicals. It has nothing to do with whether this is in drinking water or in a spa. Chemistry is chemistry and if the same chemicals are found in drinking water applications as in spas then if iodine reacts with the chemicals in one it will react with those same chemicals in the other.

    Also, you assume that the iodinated organics are only a problem if you drink the water. If that were true, then you would have a point, but the trihalomethanes and haloacetic acids have both significant skin absorption and are also volatile. That's why these chemicals are a problem not only for drinking water, but for swimming pools and spas as well. It's end-point chemicals such as chlorate, bromate, and iodate that are a problem only for drinking water but not for pools and spas because they have minimal skin absorption and are not volatile.

    Quote Originally Posted by Bernie301 View Post
    But there is more problems with the conclusion he draws from the studies he sites First study Comparison of byproduct formation in waters treated with chlorine and “iodine: relevance to point-of-use treatment”.is referring iodine tincture. This is iodine and alcohol and you might have used it treat cuts. However, I was talking about Potassium Iodide which has no alcohol. Thus this study is not relevant.
    Since the alcohol is not involved in the chemical reaction being studied, the study is most certainly relevant. You are just grasping at straws here trying to justify something that is simply not true. You so desperately want iodine to be used that you make things up about chemistry in order to justify your position. Because studies without alcohol have shown the same by-product formation, it is clear that such formation has nothing to do with alcohol being present.

    Quote Originally Posted by Bernie301 View Post
    Next reference is a FACT Sheet from the Water Research Foundation. This study is again talking about drinking water treatment and the Disinfection by Products created with chlorine or chloramine. So this Fact Sheet is actually a condemnation of chlorine. Or perhaps we should filter all iodine out of drinking water so the population can have more health problems due to iodine deficiencies. For drinking water this is absurd but such solutions have been suggested for chlorinated pools.
    No, the paper is simply saying that if you add an oxidizer (such as chlorine, but ozone or MPS or other oxidizers would do the same) to water that has iodide, then iodine is produced and that iodine can then react with organics to produce iodinated by-products and these have higher cytotoxicity/genotoxicity than brominated ones and especially chlorinated ones.

    And again, you confuse "iodine" and "iodide" and they are not at all the same thing. They are the same atom, but in different oxidation states -- iodine and specifically hypoiodous acid in the presence of organic matter is bad, iodide good in the body (in moderation). You can't have iodide or bromide in drinking water that is going to use a residual disinfectant oxidizer that can react with them to produce iodine or bromine. So yes, for drinking water the best practices treatment uses ozone first to essentially convert the bromide to bromate and the iodide to iodate though bromate is also a regulated chemical but is generally less of a problem than brominated organics (THMs, HAA5s). You should get your required iodide from food (seafood) or if needed from supplements (this is one reason iodide was added to table salt).

    Quote Originally Posted by Bernie301 View Post
    The next paper has similar problems. The specified disinfection by products sited are created by chlorine. Since the body needs iodine it seems likely that toxic compounds created with iodine might get more rapidly assimilated into the body and thus be more toxic. But, that is just speculation. Why create them?
    No, they aren't just chlorinated disinfection by-products created by chlorine. The chlorine oxidizes iodide to iodine, but iodine itself (or hypoiodous acid with which it is in equilibrium) substitutes for hydrogen in methyl ketone organics to produce THMs and in acetic acid (technically fulvic acids that break down into acetic acid when chlorinated) to produce HAA5s. I specifically quoted the section in the paper that stated "iodine-containing DBPs were found (in general) to be the most toxic and chlorinated species the least, with bromine-containing DBPs of intermediate toxicity".

    You are again confusing "iodide" and "iodine" apparently not understanding the difference. The skin absorption of the THMs has nothing to do with iodine. It's an uncharged relatively small organic molecule and these tend to be more readily absorbed through the skin and also tend to be more volatile. Your body does NOT want iodine (at least not until the thyroid explicitly oxidizes it to iodine to create mono- then di-iodityrosine and then thyroxine hormone, T4). It needs (some) iodide and that is NOT the same thing. The problem is that you are wanting to use IODINE (not iodide) for disinfection but what is good for the body in moderate amounts is IODIDE. Once you finally get this straight you'll realize your entire argument for using iodine for disinfection falls apart.

    Quote Originally Posted by Bernie301 View Post
    In several studies of pools where iodine was added and chlorine was reduced or eliminated less eye irritation was the thing most commented on by the swimmers. Since chlorine reacts to organic matter how could it NOT cause eye irritation?
    Where are these "several studies of pools" that you refer to? You never link to any peer-reviewed papers in respected scientific journals. Why is that? Please link to these studies. I already provided links showing that eye irritation was not caused by chlorine, but mostly by water with too low a salt level and also by water that has certain chloramines. Are you referring to this 1959 paper that touted iodine over chlorine due to not forming chloramines and that referred to no eye irritation in the iodine pools? People using the techniques on this forum do not complain of eye irritation and CCs almost always register <= 0.2 ppm in their pools.

    Quote Originally Posted by Bernie301 View Post
    Most people in the US are deficient in iodine. In Japan due to the consumption of seaweed and fish their intake of iodine is considerably higher and they have historically lived longer. So adding iodine to your pool can have a positive effect on your health, my dry skin went away and returned when my hot tub broke and I stopped using it.
    So eat more foods that have iodide in it or take a supplement with iodide. You apparently (repeating myself) don't understand the difference between iodide which has health benefits and the oxidized version of iodide that is iodine which when combined with organics is a health problem. An atom can have different oxidation states (numbers of electrons and therefore charge) and this changes the atom's reactivity and therefore the end result. While iodide in the -1 oxidation state (as in potassium iodide, KI, or iodide ion, I-) has positive health results, iodine in the 0 oxidation state (as in I2) or in the +1 oxidation state (as in hypoiodous acid, HOI) can be harmful due to the chemicals it produces when reacting with organics and this is particularly problematic in a spa while in the body molecular iodine in small quantities can help prevent cancer. The same is also true for chloride in the -1 oxidation state vs. chlorine (hypochlorous acid, HOCl) in the +1 oxidation state. The difference is that the chlorinated disinfection by-products are far less harmful than the iodinated by-products. You continue to ignore this fact.

    Also, with iodine (really iodide, but people usually call it iodine referring to the element and not its actual oxidation state) one can go extreme in the other direction in overdosing and is why the use of iodine for disinfection is limited to "emergency" situations. As described in this document for the Army:

    Iodine is not widely used as a disinfectant in typical municipal drinking water systems due to potential adverse health effects caused from excessive iodine intake (reference 30). It’s been suggested that chronic (long term) intake of 2 mg/day should be regarded as excessive and potentially harmful (reference 30). When ingested, iodine is converted to iodide and efficiently absorbed into the body. Most iodide resides in the thyroid gland (reference 30). Excessive amounts of iodine can cause an enlarged thyroid, a condition known as goiter (reference 30). For healthy individuals without pre-existing thyroid conditions or sensitivity to iodine, ingesting iodine concentrations associated with using IWPDs for short periods of time (i.e., 3 months or less) are not likely to experience adverse health effects (reference 31). It is recommended that pregnant women, people with known hypersensitivity to iodine, people with a history (or family history) of thyroid disease, and people from countries or localities with chronic iodine deficiency should not use iodine as a means of water treatment (reference 31).
    This paper shows skin absorption of iodine, but that is a small neutral molecule so it is not clear that the same absorption occurs from iodide. Furthermore, soaking in some iodine is not regulated so overdosing may be possible though this 1963 paper showing iodine use in swimming pools did not show an increase in protein-bound iodine levels.

    Quote Originally Posted by Bernie301 View Post
    Also chem geek speculation that the fact that my fingers stopped wrinkling was due to epson salts is empirically not true. I soaked in a tub of unfiltered tap water (containing chloramine) and a high levels of epsom salts and my fingers wrinkled.
    I already linked to the more recent studies (such as this one) showing wrinkling due to a nerve-induced reaction to water possibly evolved so that we have a better grip of objects when in water. So why don't you repeat the experiment by dechlorinating the tap water by adding sodium thiosulfate or hydrogen peroxide (for chlorinated tap water, not chloraminated) or use distilled or (activated carbon) filtered water with or without added epsom salts and see what happens? You have not proved that chlorine causes finger wrinkling at all and studies show that water causes the wrinkling -- chlorine has nothing to do with it.

    Quote Originally Posted by Bernie301 View Post
    In short you can add chlorine and then try to mitigate it effect with Cyanuric Acid and then balance your PH and due to evaporation regularly repeat. to Or you can use ozone and iodine and rarely add some iodine. You will probably experience some health benefits.
    No, by using iodine you risk more iodinated organics that are more toxic than the brominated ones and those are more toxic than the chlorinated ones. Also, for health you do NOT want iodine -- you want iodide so can get that more directly via food or supplements or if you want to dechlorinate bath water and add iodide to it you can do that though of course it's not disinfected but then generally bath water isn't disinfected because you aren't in the bath for very long and you completely drain the water when you are done. Of course, a spa is not a bath since you don't replace the water after each use, hence it requires continual disinfection.

    Quote Originally Posted by Bernie301 View Post
    Also there was a product approved by the EPA called Clearodine – A quality outdoor pool purifier. It contained 4% potassium iodide.
    This PAN Database entry for the product shows it contains 12% DCDMH (similar to bromine tabs but using only chlorine), 72% potassium peroxydisulfate (similar to MPS oxidizer, but more irritating to the skin), and 4% potassium iodide. You will note that this product registration status is CANCELLED and that the PPLS entry shows an approval date in 1968. It was called "Blue Ribbon Bleach". Science evolves and the studies that showed the relative dangers of iodine > bromine > chlorine came out later. Note that the only scientific research paper that you referenced was Comparison of Chlorine, Bromine, and Iodine as Disinfectants for Swimming Pool Water that was published in 1966. Now by itself an old paper is not a problem, but the science of disinfection by-products (DBPs) has evolved tremendously since then and found iodine to be worse than bromine which is worse than chlorine with respect to DBPs.

    So let's sum up:
    • You claimed without proof that storing or adding chlorine without ventilation will land you in the hospital while cases I found had to do with mixing sodium hypochlorite with acid (something that should not be done).
    • You claimed that oxygen could oxidize organics in pool water which is simply not true (at least not without enzymes to lower the activation energy).
    • You incorrectly attributed singlet oxygen O1 (O•) as the primary disinfectant when it is ozone itself that is the disinfectant with a half-life of roughly 15 minutes while hydroxyl radicals (•OH) are the most powerful oxidizer but very short-lived (though other radicals can also oxidize, but are also very short-lived).
    • You suggested using ozone as the primary sanitizer, but this is not allowed due to risks of outgassing and it is not practical due to costs of constantly maintaining an ozone level and its destructive gasses to covers and equipment.
    • You claimed that iodine could be used as a residual sanitizer but did not realize that ozone reacts with it quickly to form iodate so it will not last as a residual. Furthermore, you claimed that iodine does not react with organic matter and that is simply not true at all.
    • You have completely ignored the fact that the iodinated disinfection by-products are far more toxic than the brominated and chlorinated ones.
    • You incorrectly assumed that disinfection by-product analysis for drinking water does not apply to pools and spas because you aren't drinking the water, but you ignored the fact that the worst disinfection by-products are absorbed through the skin into the bloodstream and that they are volatile so are breathed into the lungs and again into the bloodstream.
    • You incorrectly discount studies using iodine tinctures containing alcohol even though the chemistry described regarding by-product formation have nothing to do with the alcohol and this is borne out in other studies.
    • You think that iodide should be in drinking water not understanding that disinfection with most oxidizers that provide a residual will result in the most toxic iodinated disinfection by-products. So removing iodide or converting it to iodate from ozone are actually the best approaches and that iodide for the diet should come from food sources such as seafood or from supplements as needed.
    • You incorrectly assumed that because the body needs some iodide that this is why iodinated by-products are absorbed but that is not true. You also do not understand that you cannot avoid creation of iodinated by-products if you use iodine (or hypoiodous acid) as a disinfectant so long as there are organics in the water.
    • You refer to studies on eye irritation without linking to any. If the eye irritation was from chloramines, then it is true that iodine does not form iodamines, but chloramines are readily avoided in residential pools and spas (during soaking -- they are formed in significant quantities when dosing right after a soak).
    • You think that soaking in iodide is the best way to get this element to improve your health, but its dosage is not regulated, iodide absorption may not occur though iodine absorption in a pool study did not show any significant absorption.
    • Scientific studies have shown that wrinkling is due to water, not chlorine. If soaking in iodide/iodine inhibits this response triggered by an evolutionary nerve response, then such inhibition (if true) could be a cause for concern.
    • You continually mix up iodide and iodine when they are not at all the same thing.
    • You referred to a swimming pool product with iodide that is from 1968 and whose EPA registration has long been cancelled. Similarly, the sole research paper you referred to was from 1966 prior to the research on disinfection by-products (DBPs) that showed that the iodinated organics were the most toxic by-products, worse than brominated ones which are worse than chlorinated ones.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    I understand your fear of the chlorine in your pool. But, your pool has far more dihydrogen monoxide, which is just as deadly in certain concentrations and/or uses.

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Quote Originally Posted by RobbieH View Post
    I understand your fear of the chlorine in your pool. But, your pool has far more dihydrogen monoxide, which is just as deadly in certain concentrations and/or uses.

    http://www.dhmo.org/facts.html
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    This issue of relative toxicity of iodine vs. bromine vs. chlorine is so important that I want to show some graphs from this presentation I linked to earlier. The following shows the Comparative Chronic Cytotoxicity of Haloacetamides where the Y-axis starts at 100% cells surviving and drops as the X-axis moves to the right at higher concentrations (and note that this is a log scale for concentration). Notice that the compounds with iodine in red are most toxic (lowest concentration kills the cells) while next comes bromine and the least toxic is chlorine.



    Now let's look at the Comparative Genotoxicity of Haloacetamides where the Y-axis shows the degree of genotoxicity (genomic DNA damage) and the X-axis again is concentration in a log scale. Again, iodine is in red, bromine in green, chlorine in blue.



    Now let us look at the toxicity index overall for 18 haloacetic acids (HAA), haloacetamides, acetonitriles, and trihalomethanes (THM). As I quoted before from the paper, "When this balanced design of DBPs was analyzed, the iodinated DBPs were substantially more toxic than their brominated or chlorinated analogues."



    The only saving grace for the iodinated organics that cause DNA damage is that their DNA repair kinetics are comparable to (or somewhat faster than) the rate of repair from chlorine and both are significantly faster than the rate of repair from bromine.



    However, given the vastly greater rate of damage, this somewhat faster repair rate does not help when one looks overall at the net effect as shown by examination of the toxicogenomics. Here again, iodine is in red, bromine in green, and chlorine in blue.



    To sum up, at equivalent concentrations of halogenated organics, iodine is around 500 times more cytotoxic (kills cells) and 200 times more genotoxic (DNA damage) than chlorine. You'll note that bromine is also substantially more toxic than chlorine, but less so than iodine by around a factor of 4 in cytoxicity and a factor of 15 in genotoxicity.

    There have been quite a few "alternative to chlorine" proposals and most have problems of not providing sufficient disinfection, but this idea of using iodine is the first one that is actually more toxic than chlorine and bromine which really defeats the purpose of being an alternative worth considering. Iodine is not "the forgotten alternative sanitizer for pools and spas that was extensively studied". It was not forgotten. It was simply later determined to be too toxic to be considered safe, especially compared to chlorine. Perhaps you didn't get the memo.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    I <3 data. I <3 chem geek. Thanks for the thorough response.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    What I observed after using Potassium Iodide in my hot tub was no problems with Hot tub rash, no smells, no slime, clear water and significantly healthier skin (dry skin disappeared and even fingers did not wrinkle.)
    Frankly, I think this is a potential product that needs to be more understood.

    Either because of PH or for some other reason the there was less Iodecitic acid or it is less destructive to living human tissue than has been observed.

    Perhaps because of some of the other products I also added to my hot tub. For whatever reason something about the know data on iodine makes no sense. Investigating it should be very worth while.

    If anyone is interested in a water sample please let me know.

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Cytoxicity and genotoxicity at spa levels are long-term statistical effects mostly affecting cancer rates. It won't cause an immediately noticeable effect. Whereas the increase in cancer rates from chlorinated organics from EPA-approved chlorine levels are on the order of magnitude of between 1 in 200,000 to 1 in million, the increase in cancer risk from using iodine is roughly 200 times greater so 1 in 1000 to 1 in 5000. It may be worse than this for spas due to the higher volatility and absorption from hotter water temperatures. If that's acceptable to you, then just understand that. It's not nearly as bad as smoking, for example, where 65 years of smoking increases lung cancer risk by 1 in 76 though the 1 in 1000 is roughly equivalent to 35 years of smoking (see Table 1 in this paper and Figure 3 in this paper). On the other hand, it's why iodine is no longer used in pools or spas and why the EPA no longer approves such products for such uses.

    Furthermore, your use of ozone with the iodine doesn't make sense since unless you are replenishing the iodide virtually before every soak and then adding an oxidizer, the ozone will completely convert all the iodide in the water into iodate rendering it inactive and not having any residual disinfectant in the water during your soak or whenever the ozonator is off. You can readily tell this because iodine in the water has it look green instead of blue (in this paper, "Pool water which is properly chlorinated is a brilliant sky-blue color, while iodinated water is light green."). Also, if you use your test kit, see what you measure in the water when the ozonator is off.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    I saw this interesting thread and I had to comment. Potassium iodide is a strong antifungal, oddly its hard to find much on its other antimicrobial properties(if any). Just exposing it to air, it will slowly release iodine, though I'm not sure at what rate. Bernie mixing ozone with the iodide makes iodine not iodate http://www.ucar.edu/learn/1_7_2_29t.htm .Chem geeks arguments appear strong however I wonder if there is some underlying error. Consider that in our own bodies we use iodide and go to great extents to convert it to iodine and to recycle it. We seem to use iodine as a second immune system. iodide is brought into the thyroid and mixed with hydrogen peroxide(hydrogen peroxide is extremely damaging) to release free iodine where it binds to create thyroid hormones, mostly T4 and a little T3. Bernie if you mix a little hydrogen peroxide with potassium iodide you will see it turn yellow from the iodine released(you might try this with your ozone maker on a smaller more concentrated scale to confirm this the yellow color is the giveaway-or if starch turns black-blue when mixed). The thyroid hormones are circulated in the blood stream and mainly converted in the liver and kidneys to the most active form T3(and some RT3) and further reduced until all iodine is removed. The conversion plucks an iodine atom and leaves it in place resulting in localized concentrations of iodine in those places. The thyroid is the gland with the highest concentration of iodine(and selenium) in the body and interestingly thyroid cancer is the least dangerous cancer you can have. Some doctors were talking about calling it something other than cancer because its survivability is so high, and most people freak out at the word 'cancer'. If memory serves its over 95% after 10 years. Our government says our tolerable upper limit is 1mg/day which is a very interesting number considering it had been common to treat people in the gram range for extended periods of time for different afflictions. I've read several of the reviews in the studies from the swimmers who used the iodine pools, the stats were impressive, almost everyone preferred iodine and a few were indifferent. No one preferred chlorine. I suspect that chlorine may also interact with our thyroids in negative ways. Some of the highest TPO antibody levels (Hashimotos which is an autoimmune disease) I've ever seen were in swimmers. I find it hard to believe that we would be swallowing both iodine and iodide (they tend to occur together) and it would be interacting with the food we eat and the bacteria in our guts much like it would be in a pool(except for a different PH) and that we would have an increased rate of cancer because of it.

    By the same argument I could say hydrogen peroxide is and extremely damaging substance, yet our bodies have evolved specific mechanisms (glutathione peroxidase) to deal with that toxicity. Putting mice ovary cells in a petri dish and treating it with chemicals may not act the same as those chemicals in a fully functioning mouse body. In vitro is not in vivo. Do you have any in vivo studies indicating the same damaging effects for these chemicals chem geek?

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Quote Originally Posted by sameul11 View Post
    Chem geeks arguments appear strong however I wonder if there is some underlying error.
    I highly, highly doubt it. Chemgeek doesn't post information carelessly.

    I also find it very curious that your first post on this forum is a detailed response to this thread, so you too now have my attention.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    I for one love when new members post up some nonsensical method that goes against Chlorine and or Bromine, only to have Richard show them where their issues are...that is why this site is so trusted, there is no one here looking to make money, only help people with facts.

    LOL...I can only wait to see what the "NEW" product that will be sold as the "Magic Bullet" for water chemistry.

    . An Iodineator?

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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Welcome to TFP!

    Quote Originally Posted by sameul11 View Post
    Potassium iodide is a strong antifungal, oddly its hard to find much on its other antimicrobial properties(if any). Just exposing it to air, it will slowly release iodine, though I'm not sure at what rate.
    It's very slow. You can tell if potassium iodide has been oxidized since it will turn from white to yellow. Hydrogen iodide can react more quickly but only practically fast at high temperatures. I'm not sure what your point is though. We aren't talking about iodide or iodine themselves but rather were discussing the disinfection by-products, specifically the iodinated organics which are formed when iodine reacts with an organic compound.

    Quote Originally Posted by sameul11 View Post
    Bernie mixing ozone with the iodide makes iodine not iodate http://www.ucar.edu/learn/1_7_2_29t.htm .
    This is only half-true. Ozone reacts with iodide to make not only iodine but in water the iodine will form hypoiodous acid (HOI) and can be further oxidized to iodate (IO3-). This happens very quickly as described in this paper I linked to earlier. Do you not believe in peer-reviewed scientific papers in respected journals and instead look on the Internet to find course lessons (which you didn't interpret correctly, but more on that later)? Again, it is not that ozone won't form iodine, but rather that iodine in water will also form hypoiodous acid and hypoiodite ion and that these both react very quickly with ozone to form iodate. The Schoenbein Paper in the link you gave has the iodine remain mostly as iodine because it is not in water. Note that the paper must be dried before used to test for ozone - as the link you gave says in the instructions: "Set the paper out of direct sunlight and allow it to dry. A low temperature drying oven works well if available.". In fact, the lesson itself states that "this activity works best in areas of low humidity and high ambient ozone concentrations". When the humidity is higher or if the paper is not properly dried, then the iodine can dissociate in water to form hypoiodous acid (HOI) and hypoiodite ion (OI-) which both react with ozone to form iodate ion (IO3-).

    I hate to repeat myself but apparently you don't bother to read the detail in the posts I've already made in this thread so I strongly encourage you to do so since I don't want to copy everything over again (but will do so for one item now). For example, in this paper it sums up both points that you are missing -- that ozone oxidizes hypoiodous acid (HOI) to iodate ion (IO3-) and that without the ozone the HOI will react with some organics to form dangerous iodinated organics.

    Although the formation of brominated DBPs has been studied for many decades, research on iodinated DBP formation has been an emerging area of concern. Iodide can react with ozone, chlorine, chloramines or chlorine dioxide to first form hypoiodous acid (HOI) (Bichsel & von Gunten 2000; Hua & Reckhow 2006). Ozone or chlorine can then further react with HOI to form iodate, which acts as a sink for the iodide. Alternatively, HOI can react with NOM to form iodinated DBPs. The yield of iodinated DBPs generally follows the order: chloramines (NH2Cl) > chlorine dioxide (ClO2) > chlorine (Cl2) ≫ ozone (O3).
    Quote Originally Posted by sameul11 View Post
    Consider that in our own bodies we use iodide and go to great extents to convert it to iodine and to recycle it. We seem to use iodine as a second immune system. iodide is brought into the thyroid and mixed with hydrogen peroxide(hydrogen peroxide is extremely damaging) to release free iodine where it binds to create thyroid hormones, mostly T4 and a little T3.
    So what does this have to do with the iodinated organic disinfection by-products which have been demonstrated to be far more mutagenic and cytotoxic than their brominated and especially chlorinated counterparts? Because the bather-load is high in the relatively small spa volumes of water, there are more disinfection by-products formed there. The mechanisms the body has to isolate and reduce oxidizing agents before they cause too much damage are not present in spa water. So you can't compare what goes on in the body with what happens in a spa. In fact, hypochlorous acid is also formed in some cells but again the formation and usage of oxidzers in the body are done in very specific chemical environments designed to minimize formation of by-products. This is not true in a spa. Once the by-products are formed, it's too late and they are not readily handled by the body so can cause more damage.

    Quote Originally Posted by sameul11 View Post
    Bernie if you mix a little hydrogen peroxide with potassium iodide you will see it turn yellow from the iodine released(you might try this with your ozone maker on a smaller more concentrated scale to confirm this the yellow color is the giveaway-or if starch turns black-blue when mixed).
    As noted in the lesson that you quoted, you want to do this dry, not wet, or else you can produce more iodate (via hypoiodous acid or hypoiodite ion) than iodine.

    Quote Originally Posted by sameul11 View Post
    The thyroid hormones are circulated in the blood stream and mainly converted in the liver and kidneys to the most active form T3(and some RT3) and further reduced until all iodine is removed. The conversion plucks an iodine atom and leaves it in place resulting in localized concentrations of iodine in those places. The thyroid is the gland with the highest concentration of iodine(and selenium) in the body and interestingly thyroid cancer is the least dangerous cancer you can have. Some doctors were talking about calling it something other than cancer because its survivability is so high, and most people freak out at the word 'cancer'. If memory serves its over 95% after 10 years.
    Again, you are missing the point of this thread. It is NOT that iodine enters the body to cause problems, but rather that iodine (or hypoiodous acid with which it is in equilibrium) reacts with organics both in the spa water and in skin and it is these iodinated organics that are the problem, not iodine itself. This is also true from brominated and chlorinated by-products. Bromine or chlorine itself is not a cancer problem in the body -- it is these compounds combined with some types of organics that are a problem.

    Quote Originally Posted by sameul11 View Post
    Our government says our tolerable upper limit is 1mg/day which is a very interesting number considering it had been common to treat people in the gram range for extended periods of time for different afflictions. I've read several of the reviews in the studies from the swimmers who used the iodine pools, the stats were impressive, almost everyone preferred iodine and a few were indifferent. No one preferred chlorine. I suspect that chlorine may also interact with our thyroids in negative ways. Some of the highest TPO antibody levels (Hashimotos which is an autoimmune disease) I've ever seen were in swimmers. I find it hard to believe that we would be swallowing both iodine and iodide (they tend to occur together) and it would be interacting with the food we eat and the bacteria in our guts much like it would be in a pool(except for a different PH) and that we would have an increased rate of cancer because of it.
    Again, you are completely missing the point. This is not about iodide intake nor about iodine itself. It is about iodine (or hypoiodous acid) which has reacted with organics to form iodinated organics that are mutagenic and cytotoxic. Bromine and Chlorine both do this as well, but their by-products are less mutagenic and cytotoxic. That was the point. You get problematic chemicals from any of these, but the iodinated organics are the worst. So if you have any health concerns about chlorine or bromine, you certainly wouldn't want to be promoting iodine.

    Also, regarding chlorine, the fact that it is so reactive means that it won't get very far penetrating the skin or anywhere else in the body. It will oxidize compounds like ammonia and some amino acids and will react with organic material to produce chlorinated disinfection by-products. As for food, it contains iodide, but very little iodine and that's a good thing because iodide is a nutrient the body needs. This review of evidence notes that the term iodine is used improperly to encompass different forms but they have different effects (and even they incorrectly write iodate as NaIO when that is actually sodium hypoiodite):

    In the medical literature, the generalization of the term iodine can create confusion. The term iodine represents essentially any form of the molecule, including molecular iodine (I2), iodide salts (NaI or KI), iodate (NaIO), and/or lipids or proteins containing iodine (iodo) moieties such as iodotyrosine or iodolactones. The most well studied form is iodide salts, such as sodium iodide (NaI) and potassium iodide (KI), which are frequently used in supplementation of iodine to entire populations. Throughout this review the term iodine will be used as a general term, and specific forms given as a parenthetical descriptor whenever possible [eg, iodide (I-)].
    As the studies show, molecular iodine (I2) may be a preventative in carcinogenic processes and the consumption of iodate orally may have some of it convert to molecular iodine from the acidity in the stomach. The review of studies shows that too much iodide may be a problem for the thyroid and proposes consuming molecular iodine but the best approach is to get the iodine substances from food.

    The difference in using iodine in a spa vs. taking supplements is the likely concentration difference of the iodinated organics. Whereas the daily recommended iodine dose is 1 mg/day diluted throughout the body, having just 1 mg/L (ppm) iodine in a 350 gallon spa is 1325 mg and this is a lot of iodine that can combine with the relatively large amount of organics in a spa and does so over an extended period of time. So far more iodinated organics are formed in a spa (and can accumulate over time) than would be formed in the human body from food or nutritional supplements.

    Quote Originally Posted by sameul11 View Post
    By the same argument I could say hydrogen peroxide is and extremely damaging substance, yet our bodies have evolved specific mechanisms (glutathione peroxidase) to deal with that toxicity. Putting mice ovary cells in a petri dish and treating it with chemicals may not act the same as those chemicals in a fully functioning mouse body. In vitro is not in vivo. Do you have any in vivo studies indicating the same damaging effects for these chemicals chem geek?
    Again, you are still missing the point assuming that the problem with iodine is its oxidative power once in the body. The problem is AFTER iodine, or more specifically hypoiodous acid (HOI) has reacted with organics. It is some of those compounds that have strong skin absorption and/or volatility and are genotoxic and cytotoxic.

    As for in vivo studies, the correlation of in vitro studies on genotoxicity and cytotoxicy have always been very strong to in vivo studies and many of the in vitro studies use mammalian cells (see this link). However, there have been relatively few in-vivo studies on the halogenated disinfection by-products and even fewer on the iodinated ones. Nevertheless, this paper refers to one of the in vivo studies:

    Iodo-acids are a new, toxicologically significant class of DBP that was recently identified as part of a U.S. Nationwide Occurrence Study (Plewa et al., 2004b; Weinberg et al., 2002). Iodoacetic acid, one of five iodo-acids identified for the first time in chloraminated drinking water, has recently been shown to be more genotoxic and cytotoxic to mammalian cells than all DBPs that have been studied, including the regulated HAAs and bromate (Plewa et al., 2004b). It is a factor of 2X more genotoxic than bromoacetic acid, which is the most genotoxic of the regulated HAAs. Low M levels of iodoacetic acid caused these effects, which was similar to doses of iodoacetic acid that caused developmental effects (neural tube closures) in mouse embryos (Hunter and Tugman, 1995; Hunter et al., 1996).
    This paper also describes in vivo studies of the monohaloacetamides including that of iodinated by-products (i.e. iodoacetamide). As is often the case, the in vivo studies confirm the toxicity found in the in vitro studies.

    Cytotoxicity and genotoxicity of monoHAcAms are determined by the leaving tendency of the halogens and decrease following a rank order of iodoacetamide (IAcAm)>bromoacetamide (BAcAm)≫chloroacetamide (CAcAm).
    :
    Exposure to the monoHAcAms decreased the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the levels of malonaldehyde (MDA) and increased the level of 8-hydroxy-2-deoxyguanosine (8-OHdG), indicating that each exposure generated oxidative stress in mice liver. Metabolomic alterations were also induced by each monoHAcAms exposure. In addition, disruptions of metabolic pathways, related to amino acid, energy and lipid metabolism, were identified based on the significantly changed metabolites.
    This paper looked at some pathways from haloacetic acids, but only the chlorinated and brominated by-products, not iodinated ones. This WHO document describes several in vivo mutagenicity results but again looking at chlorine and bromine and not iodine. Similarly, this paper summarizes a variety of in vivo studies, but again with chlorine and bromine and not with iodine. Nevertheless, given the far greater in vitro mutagenicity and cytotoxicity of the iodinated compounds and the few in vivo studies showing them to be consistent with the in vitro studies, it's pretty clear that of the three halogens, iodine is the one to be avoided the most in terms of its disinfection by-products.

    This paper shows that iodine itself and some iodine containing compounds are not genotoxic nor cancer causing and that iodine deficiency increases cancer, but that is already known about iodine. Unfortunately, they did not focus on the disinfection by-product compounds (they did look at methyl iodide that induced local sarcomas in rats as well as iodinated glycerol which also showed some carcinogenic activity in rats, but those aren't the primary disinfection by-products formed in spas).

    This paper (which you can get for free here) refers to mammalian cell toxicity and notes that "new in vivo toxicology studies and human cell toxicogenomic studies (38) are currently being planned", but the in vivo toxicology studies have not been completed yet (except as I noted above) and I suspect most will focus more on chlorine and bromine than iodine. The human cell toxicogenomic studies have been done and are what I linked to in the presentation from which I showed the graphs in an earlier post.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Quote Originally Posted by Brushpup View Post
    ... I also find it very curious that your first post on this forum is a detailed response to this thread, so you too now have my attention.
    Mine, too. I'm still wondering about Standard University mentioned in the first line of this thread.

    This is the reason Dave created the circle of trust so we could discuss these things. I will be watching you.
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    Re: The forgotten alternative sanitizer for pools and spas that was extensively studi

    Since this June, 2014 paper I referred to near the end of my previous post is one done with in vivo studies on rats and since you have to pay for it, I copied the graphs from it to show you that in vivo the SAME order of iodinated compounds being more toxic than brominated one being more toxic than chlorinated ones shows up. So you're argument about things perhaps being different in vivo simply isn't true and while that has been proven over and over again with chlorine and bromine due to more studies done with those, it is also holding true (no surprise) with iodine.

    Oxidative Stress Induced by monoHAcAms.
    In order to evaluate the oxidative stress induced by monoHAcAms, key biomarkers (CAT, SOD, GSH-Px, MDA, and 8-OHdG) in liver were detected in this study and the results were presented in Figure 1. Compared with the control group, the monoHAcAms inhibited the activities of CAT, SOD, and GSH-Px, and decreased the level of MDA in a dose−response manner with a rank order of effect expressed as IAcAm > BAcAm > CAcAm. In addition, the monoHAcAms increased the level of 8-OHdG followed a similar rank order. This rank order was observed with other toxicological end points.

    Liver is sensitive to oxidative stress, and CAT, SOD, and GSHPx are all antioxidases, which play important roles in liver antioxidant defense system to inactivate the ROS produced by environmental chemicals. Oxidative stress will be induced when ROS generation overloads antioxidant defenses, and then affect the normal function of lipid, protein and nucleic acid. In this study, the decreased activities of CAT, SOD, and GSH-Px indicated that monoHAcAms induced oxidative stress in mice livers. In addition, lipid peroxidation might be induced in the livers of monoHAcAms-treated mice according to the significantly decreased MDA, which is considered as one of the endproducts in the lipid peroxidation process. Furthermore, 8-OHdG is an oxidation product of DNA, which is oxidized by various ROS. The dramatically increased 8-OHdG combined with the inhibition of CAT, SOD, and GSH-Px and decreased MDA demonstrated that oxidative stress and DNA damage in mice livers were induced due to the monoHAcAms exposure. Similar results have been found that monoHAAs can induce oxidative stress and lead to genotoxicity. These results suggested that monoHAcAms induced oxidative stress in mice liver and shared a common mechanism.


    Their conclusion was the following:

    In conclusion, these data support our hypothesis that the monoHAcAms can induce oxidative stress in mice and the rank order of IAcAm > BAcAm > CAcAm is consistent with other toxicological end points. In addition, metabolomic alterations were also found in mice treated with each of the monoHAcAms. Furthermore, the alterations of pathways related to amino acid metabolism, energy metabolism and lipid metabolism were identified based on SCMs. In this study, metabolomic methods were proved to be helpful to provide comprehensive views for the toxic effects of monoHAcAms.
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