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Mps Allergy


theoabear

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My dermatologist confirmed my skin allergy to MPS. I was the only one in my family to experience the large red bumps on arms and legs. The tub (400 gal.) was drained - filter cleaned with Aqua-EZ (great product - removes iron and clarifies water instantly!) - and tub then refilled using Dichlor only and new mineral cartridge.

It worked - no more bumps. Here's the issue - my son put in 2 tbls of the old shock cleaner with MPS the other night after he left (yes, I should have thrown it away). Took a tub last night - the bumps reappeared this morning - I asked him what he added and he confirmed it was the older bottle of shock. So - my question is - will just a few tbls. of MPS wear out if I leave it for a few days? If I add more dichlor will that burn it off? Or - do I need to drain and refill tub again? Thx in advance!

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Interesting.. I am having what I beleive is a similar problem.

Not MPS mind you but PPMS (potassium peroxymetasulfite) Natures Way brand of shock. Which isnt MPS, I thought it was until I read the bottle. Seems "non chlorine shock" is more than just MPS. (Monopersulfate) in my case it was PPMS. (Potassium Peroxypersulfate)

I wonder if I ALSO would have an allergy to MPS. Originally it was suggested here that I might have focculitis but it is "good" to hear others who have a itchy rash that isnt pimples. I've had my water tested now twice. They both said "You are good"

Dunno. I might have to get to the doctor as well I am itchy right now in quite a few places.

The my thread is here, you might see if there is some similarities but it sounds like we are using different chemicals.

http://www.poolspaforum.com/forum/index.php?showtopic=44325

Ive got bumps.. but not red (unless they are the ones that I scratched raw)

I went in yesterday for 15 minutes in the morning and about an hour last night.. this morning.. woke up 4am.. with itching and a little bit of burning as well.

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The MPS will get used up if there are things in the tub to oxidize. So it will last longer in a clean tub. It doesn't outgas like chlorine so if the water is clean it could last a while. You could always add some hydrogen peroxide to the tub to get rid of it and then add chlorine until you get an FC reading again.

As for the Nature's Way shock product PPMS, are you sure that is potassium peroxymetasulfite? They might mean potassium persulfate aka potassium peroxydisulfate which is the known minor contaminant in MPS products that is usually the one most irritating to the skin. It's a bit surprising that this product is used since it's more of a known irritant than MPS and if one could get pure MPS with this minor contaminant then it might not be so irritating to some.

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check it out

CrIgQKx.jpg

I am ITCHY as hell right now.. :)

hoping this stuff dissappates..

we are switching to chlorine and bleach.. I picked up plain clorox at Home Depot on the way home. We have to figure out THAT system now.

I was just thinking.

oh no.. I have sticks that test MPS.. but.. if i was using THIS.. I wasnt adding MPS.. I was adding PPMS..

ugh... no WONDER I am burning.. people put 1-2 tsp per person.. my wife was using 4-6 TSP..

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That says "Potassium Peroxymonosulfate", NOT peroxymetasulfite or peroxypersulfate as you had indicated before. Peroxymonosulfate is a synonym for Monopersulfate so IS THE SAME AS MPS.

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YEP, PPMS is the same as PMPS which sometimes is written as KMPS or KPMS since K is the chemical symbol for potassium.It usually just called MPS in the trade. It's all just alphabet soup for the same stuff.

Bottom line, it's a known irritant and sensitizer so if you are having a reaction then switch to either 3 step bromine using bleach as your oxidizer or to the dichlor/bleach method of chlorine. Bromine itself can be a minor sensitizer to some people but it is rare and most problems with bromine tubs are really from the MPS that is commonly used as an oxidizer in them.

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  • 1 year later...

My Wife has the same reaction to MPS, I thought this could be the problem, so I stopped using it about two weeks ago. There is still some residual left in the tub because she flares up every time she gets in, so how much hydrogen peroxide should I use to neutralize the MPS in a 400 gal. tub?

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I am not certain if hydrogen peroxide will neutralize MPS the way it most certainly does with chlorine. Though the thermodynamics say that it should occur since MPS as an oxidizer has a potential of +1.85V large enough to overcome the potential of hydrogen peroxide as a reducer of -0.695V, I do not know if the reaction is kinetically favorable. If it is, then the amount to use would be the same amount of hydrogen peroxide you would use to lower FC and in fact if you were to measure Total Chlorine (or FC+CC) then you could use that as your reference amount where the same volume of 3% hydrogen peroxide neutralizes FC from an amount of 6% bleach.

So in 400 gallons every 1 ppm FC would need 0.83 fluid ounces of 3% hydrogen peroxide to neutralize it. You probably don't have more than 5 ppm FC equivalent of MPS in the spa. In fact, I'm surprised if after two weeks you have any MPS left unless you haven't used the spa at all in that time and had added a bunch of MPS (maybe too much) after your last soak.

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Yes, if she's sensitive to sulfates, then a drain/refill is the only way to get rid of them. If that is the case, then you would need to avoid use of dry acid as well since that also results in sulfate. Muriatic Acid (hydrochloric acid) results in chloride so ordinary table salt.

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When MPS gets used/consumed, it results in sulfates. If prior to using MPS you had used dry acid (sodium bisulfate) in your spa and there was no problem, then yes your wife is probably not allergic to sulfates but just to MPS or other chemicals in non-chlorine shock. The actual non-chlorine shock product contains not only MPS but also a small amount of an irritating chemical called potassium persulfate (not the same as monopersulfate). So that could be the actual chemical to which she is sensitive in which case a drain/refill is your safest bet to starting over. Persulfate is broken down by silver ions which is one reason why the Nature2 system which uses silver ions and MPS is not as irritating as using MPS alone.

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Thanks for the info Chem Geek. We have been using Dichlor sanitizer prior to the MPS and she was fine with it. So it must be the MPS or one of the chemicals in it. I'm gonna drain and refill using only the dichlor, we'll see how this does. Thanks again!

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  • 2 weeks later...

My wifes rash is back with a vengeance! the only thing I can think of is the dry acid I use to lower the TA (sodium bisulfate). When the tub was drained and refilled she was fine for a while, (about a week) but then she started breaking out AGAIN. Our source water has a very high alkalinity, it's 250, but the ph is 7.4 so adding the dry acid over a period of about a week has increased the amount in the tub. At this point it's the only thing I can think of that would be causing her rash. Sanitizer is fine, no MPS, the only other chemical I use is pool tonic to get rid of the phosphates in our source water. Can someone HELP!!. Is there any way to lower TA quickly and safely without the use of Ph decreaser or Muratic acid?

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You have to use acid to lower the TA, but Muriatic Acid doesn't have sulfates and will just result in chloride as in ordinary sodium chloride table salt. So if you avoid MPS and dry acid (sodium bisulfate) you won't be having any sulfates in the water.

Though there are articles on contact dermatitis from sodium lauryl sulfate, I don't see such articles for plain sulfate ions.

I presume the phosphate remover is lanthanum chloride. You normally would not need to use that in a hot tub.

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My water test print out from the spa store tells me to use 1oz per day for 9 days to lower the TA from 250, but 9oz does not bring it down. The hot tub store told me to put 2oz every 3 hours until its within range. I have used close to 35 oz to get it within range, could this be the problem? too much dry acid, and if so, why doesn't the TA come down to within range after 10 - 12oz? I have been putting in the dry acid since I refilled the tub on the 31st of Dec. and my wife only started breaking out 2 days ago. Do you think that there is just too much Decreaser in the tub?

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I suppose high sulfate levels could be a problem -- I just haven't (yet) found scientific papers or medical reports on it. That doesn't mean it's not real or the cause.

Every 1 ounce weight of dry acid (93.2% sodium bisulfate) in 400 gallons lowers the TA by 7.3 ppm. 35 ounces would lower the TA by 255 ppm. So yes, it takes a lot of dry acid to lower the TA from 250 ppm, but the amount you added should lower the TA too low if indeed you started at 255 ppm. Note that 12 ounces would only lower TA by 87 ppm so not enough. Either your readings on TA aren't right or the concentration of dry acid isn't what it should be or you added something else possibly when the pH got too low from the dry acid and that raised the TA back up (pH Up raises TA). The right way to lower the TA is to use acid and aerate the water -- one should not add any chemical to bring the pH back up as that will also raise the TA thus defeating the purpose.

Something still doesn't sound quite right about the source of the breakout. If you drain/refill and use Muriatic Acid and aeration to lower the TA, then you would eliminate MPS and sodium bisulfate as the sources of the problem.

I presume that the disinfectant level has never gone to near-zero since clearly that could allow bacteria to grow and form biofilms and those could cause skin problems.

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We have had our spa since September and have drained and refilled 2 times (not counting the first fill). We purchased the ACE because from what we had read, it was easier to maintain.

The first drain was due to the chlorine. We couldn't keep a stable amount in the spa. This was due to high phosphate levels in the source water, or so we were told by our local dealer.

The second drain was due to the MPS which we thought my wife was allergic to. The breakout and itching on her back, arms and legs.

Now, after the drain mentioned directly above, she did fine. No breakout, no itching for the first 7-8 days. Our source water registered 250 TA and 7.4 ph and should require approximately 24oz. of dry acid according to your calculations above. I have added 35oz (ish) of dry acid (93.2%) to get TA within range. When adding the dry acid I do NOT aerate because the ph registers fine in the source water. The very next day, however, it also is too is high. I have not added any ph up because the ph has never dropped too low. Why is this?

A few days ago her rash came back as bad or worse as before. We just keep chasing the water with chemicals and it is our fear that we are adding too much to balance the readings which, of course, seems the logical reason for her breakouts. The disinfectant level has stayed steady (between 3-5ppm) with weekly shocks and pool tonic (requested by our local dealer) to kill phosphates. It seems that the more chemicals that are added, the worse her rash gets. This is not what we bargained for when we bought the tub. We are trying to find a happy balance so that we can enjoy, kick back and relax.

I'm anxious to hear your thoughts on this, once again. You have provided more information than our local dealer and for that... we thank you!

If we need to use the Muriatic Acid, where can I buy and how is it added? All at one time, or over a certain time period? The last thing we want is to risk more problems with chemicals. It seems as though we should be able to maintain the water chemistry without having to saturate the water or reach for yet another chemical to add to the madness.

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Well all I can suggest at this point is that you use Muriatic Acid for acid instead of using dry acid. You can get half-strength Muriatic Acid (15-16% hydrochloric acid) that won't fume as much. You can buy it at hardware or big-box stores (e.g. Home Depot, OSH, etc.) but check the concentration since both half-strength and full-strength are available. Sometimes one strength is in the paint section and another in the pool/spa section.

The only by-product of this type of acid is chloride salt and it is highly unlikely that sodium chloride salt water would be a problem. Note however that the water you have right now in the spa has sulfates in it so you won't know if they are the problem until such water is changed or at least diluted down to where it isn't a problem.

1 ounce of dry acid (93.2% sodium bisulfate) is equivalent to 1.7 fluid ounces (3-1/2 tablespoons or 10 teaspoons) of half-strength Muriatic Acid (15-16% Hydrochloric Acid).

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You can put the Muriatic Acid in at one time but add it slowly when the circulation is on or the spa jets (but be careful not to splash back into your eyes). You can use full-strength (31.45% Muriatic Acid) if you want to and you would use half the amount but full-strength tends to fume so can be very irritating to your nose when adding it in concentrated form. It will be fine once in the water.

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  • 1 month later...

My wife's rash just will NOT go away! We have switched to muriatic acid to balance the pH & TA, we have stopped using MPS, there is nothing in the tub but dichlor & salt. Just when we think her rash is better, she gets back in the tub, and BAM!! her rash flares back up. Her rash has never cleared up 100%. Has anyone ever heard of an allergic reaction to dichlor? I'm just not sure what to do next. I've drained / refilled 3 times since September when we got our tub. Could she be reacting to the salt? or the Spazazz we use to get the ozone smell out of the tub? If the sanitizer ever dropped to below 1 I could just say it's regular hot tub rash, but I keep the sanitizer level between 3-5 with weekly shocks. HELP!!!

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