Skin irritation and Stinging eyes

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.
christmaya7
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Skin irritation and Stinging eyes

Postby christmaya7 » Tue 21 Aug, 2007 04:35

We always use the swimming pool in our school for our swimming subject. Until such time we slowly noticed that we are having skin irritation and stinging eyes every after our swimming lesson ends. What is the cause of this? Does the pool maintenance put too much chlorine to the water?
Anyone have the answer to this?


chem geek
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Postby chem geek » Tue 21 Aug, 2007 12:08

Is it an indoor pool? If so, then they are likely not using Cyanuric Acid (CYA) in the water. In that case, the disinfecting chlorine concentration is much, much higher than in outdoor pools that use CYA -- literally 10-20 times higher or more. My wife's swimsuits degrade over just one winter season of 5 months in an indoor pool with 2 ppm FC and no CYA while in our own outdoor pool at 3-6 ppm FC with 30 ppm CYA there is no degradation whatsoever over a summer season of 7 months and only a slight degradation noticeable after 4 years of summer seasons.

Is it also possible they are not using CYA in an outdoor pool, though that is far less common (but is sometimes done in commercial pools). And they could be using CYA but have the chorine level very high.

Also, stinging eyes can occur from the pH being away from 7.5. It does sound like the pool is out of balance. If you have a good test kit, you can test the water yourself and point this out (politely) to whomever runs the facility.

Richard
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Re: Skin irritation and Stinging eyes

Postby Backglass » Tue 21 Aug, 2007 12:30

christmaya7 wrote:We always use the swimming pool in our school for our swimming subject. Until such time we slowly noticed that we are having skin irritation and stinging eyes every after our swimming lesson ends. What is the cause of this? Does the pool maintenance put too much chlorine to the water?
Anyone have the answer to this?


Unfortunately, chlorine get's a bad rap as being the cause of all skin and eye problems. Most likely as chemgeek mentioned, it's a ph problem or CYA problem.

Believe it or not, if they put in too much chlorine and everything else is in balance...you wouldn't even notice. It's when they let the CC and ph get too high that you start smelling chlorine and rubbing your eyes.

Poor chlorine...the ugly duckling of the pool world. :lol:
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christmaya7
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Skin irritation and Stinging eyes

Postby christmaya7 » Tue 21 Aug, 2007 20:21

Yes, it is an indoor pool. When I asked the in charge of the pool of what chemical he used to disinfect the water, he told me that he just only use chlorine...
So it wasn’t really the high chlorine content of the water causes those problems but it is more likely on the imbalance CYA and pH content or the absence of CYA in the water?
No, I don’t have a test kit. If only I have one, I will test the water on my own to make sure that the chemical content is balance or not, and report it to our pool administrator to prevent this annoying skin irritation again.
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Postby fatybabe » Wed 29 Aug, 2007 01:03

well High chlorine levels cause irritation too much of anything will cause problems anyhow.


If your situated in an indoor pool try to check for a strong pungent chlorine smell, that is what we call chloramines in that case tell the operator to shock the pool.

You reallys hould point out to the facility manager to change yr pool to use of BCDMH it is better suited for indoor and heated pool applications.

A good source for this would be Hydrotech.
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Skin irritation and Stinging eyes

Postby chem geek » Wed 29 Aug, 2007 12:03

FYI - BCDMH is what is normally found in bromine spas and is a combination of chlorine and bromine attached to dimethylhydantoin. There are other methods for creating a bromine spa or pool including separate addition of bromide and an oxidizer, either chlorine or a non-chlorine shock (potassium monopersulfate) without the extra hydantoin.

At any rate, bromine pools have different smells. They don't get chloramines but bromine has a smell of its own. Also, more people are allergic to bromine than chlorine. The lack of CYA use in indoor pools makes the production of chloramines occur much faster than in outdoor pools (the poor air circulation and lack of sunlight in indoor pools are also factors), but I don't think you will be able to convince them to add some CYA to the pool. If they do, then even 10 ppm CYA should help.

I'm currently communicating with the CDC and others about this since the asthma and respiratory problems found with competitive swimmers and small children in indoor pools could be resolved through use of some CYA to reduce the rate of production of disinfection byproducts by a factor of 10 or more. I also know my wife will appreciate not having swimsuits degrade (elastic gets shot) after just one winter season in an indoor pool while in our outdoor pool with CYA the swimtuits don't degrade (or have slight degradation after 4 years). The difference is the disinfecting chlorine (hypochlorous acid) concentration -- the indoor pools essentially being "overdosed" by a factor of 10-20 because they don't use CYA.

Richard
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Postby fatybabe » Wed 29 Aug, 2007 21:57

Well as a personal preference id always gow ith BCDMH with indoor pools, up until now i havent had any odour reltaed problems so i consider that the best.

Richard pointed out BCDMh is a combination of bromine and chlorine what happens is the HYPOclorous acid is used to reactive the spent bromine ions or should we say BROMAMINES, BCDMH has less of a corrosion related problem than that of chlorine when you are talking of indoor heated climates.

Besides Bromine dont evaporate just as fast as that of chlorine in heated pools hence you tend to find for indoor and spas ppl use bromine for the outdoors they use chlorine.
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Postby chem geek » Wed 29 Aug, 2007 22:08

I think it should be noted that the primary reason chlorine is used more often in pools than bromine, even in many indoor pools, is cost. Bromine is quite a bit more expensive. So with spas that don't use a lot, bromine is often seen. In indoor pools, it's more of a mix. In outdoor pools, it's almost always chlorine because there is no equivalent to CYA to protect bromine from breakdown from sunlight (though it does not breakdown quite as fast as unprotected -- i.e. no CYA -- chlorine).

I agree, it's a personal preference. A well-maintained chlorine pool can have virtually no smell, but the key is "well-maintained" and that is harder to do with an indoor pool (without CYA and without good air ventilation).
Guest

Postby Guest » Thu 12 Feb, 2009 17:54

You should never, ever, use CYA in an indoor pool. Ask any aquatic expert and they will tell you the same thing. Outdoor pools need it because of the sun, wind, leaves and other elements than can rapidly reduce the effectiveness of CL2. The only pools that I've seen use CYA at an indoor pool loose clarity and overall chemical balance. Regards, Ken
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Skin irritation and Stinging eyes

Postby chem geek » Thu 12 Feb, 2009 20:28

Ken,

You shouldn't use too much CYA in ANY pool, indoor or outdoor, but it is absolutely positively not true that the ONLY reason CYA is used is to protect chlorine from breakdown from the UV in sunlight. CYA SIGNIFICANTLY reduces the active chlorine (hypochlorous acid) concentration so if you don't use it in an indoor pool and instead have 1-2 ppm FC with no CYA, then you are significantly over-dosing the pool with active chlorine. I don't care if so-called industry experts say not to use CYA in indoor pools -- that blanket rule doesn't match reality (and it's not the only "rule" that's been debunked, but I won't get into those others here).

My wife experiences this difference every winter season when she has to use a community center pool with 2 ppm FC and no CYA (pH and other parameters are normal). Her swimsuits lose elasticity in just one winter of use and her skin is flakier (drier) and hair frizzier. In our own outdoor pool over the summer with 3 ppm FC and 30 ppm CYA, the swimsuits last for years and the effects are minimal on skin and hair. The difference in active chlorine (hypochlorous acid) concentrations between the two pools is a factor of 20. 3 ppm FC with 30 ppm CYA is technically equivalent to a pool with about 0.1 ppm FC and no CYA.

Saltwater Chlorine Generator (SWG) pools that don't have CYA in them are susceptible to faster corrosion of stainless steel as noted in this older study . We've seen examples of this on some pool forums -- one pool had serious corrosion of stainless steel in under one year from somewhat higher 4-5 ppm FC levels, but no CYA because it was an indoor pool.

The relationship between chlorine and CYA has been known definitively since at least 1974 as described in this paper . The book this paper is in has been out-of-print, but I received permission to scan/post it. The main reason for the "CYA is only needed to protect chlorine from sunlight" rule is that the chlorinated cyanurate manufacturers do not want you to know how much CYA reduces chlorine effectiveness. Otherwise, you'd realize that continued use of stabilized chlorine increases CYA quickly and leads to algae growth as the chlorine becomes less effective and that this is why you must use a supplemental algaecide weekly or a phosphate remover (at extra cost to the homeowner and profit to the manufacturer).

The amount of CYA that should be used in an indoor pool would be low -- around 20 ppm -- usually with around 4 ppm FC in a higher bather load setting or 2 ppm FC in a residential setting. What you have seen with CYA in indoor pools is probably when they used inline chlorinators with Trichlor pucks where the CYA would get way too high. In that case, water can turn dull or cloudy since oxidation takes too long because the active chlorine level is too low (the FC/CYA ratio is too low). This even occurs in outdoor pools where algae often develops as the CYA rises if the FC is not raised proportionately. The solution, of course, is to properly manage the CYA level and keep the FC/CYA ratio roughly constant (see this chart ).

The following are chemical facts which is why one should use chlorinating liquid (or bleach) or a saltwater chlorine generator instead of stabilized chlorine once the CYA level is set.

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.

The above has strong implications. With Trichlor, even a low chlorine demand of just 1 ppm FC per day would result in a 6*30*0.6 = 108 ppm CYA increase in 6 months if there were no dilution, say from backwashing (though that isn't that much unless the pool is smaller). This is what happened in my own pool (with a cartridge filter) years ago when after just 1-1/2 seasons of using Trichlor in a floating feeder, the CYA was at 150 ppm, the chlorine was hard to maintain with pucks, and the water turned dull with a nascent algae bloom (plus I had some stainless steel mounts rust when the feeder "parked" itself nearby at times). And this was in spite of using algaecide, but I was only using it every other week. Had I used it every week, I would probably have gotten by for a bit longer. My pool's fill water has 300-500 ppb phosphates that the water district adds for corrosion control.

Today, I only use 12.5% chlorinating liquid in my 16,000 gallon pool (after raising the CYA initially) and my pH is stable and it only costs me around $15 per month. It has been algae free and clear as a bell in spite of the phosphate level being 2000-3000 ppb. Understanding what really goes on and not necessarily believing industry lore has made all the difference.

Richard

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