Irritation from pool water

[writingwizard]

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[Bama Rambler]

Combined chlorine between .2 and .7 ppm is pretty high. I bet that's where the irritation is coming from.
How high is the bather load on a daily basis?

How are you testing the FC and CC?

Are there any regulations preventing you from using CYA in the pool.

 

[writingwizard]

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[JamesW]

The MPS contains a minor ingredient that is a known irritant. MPS can also register as CC unless you use a special test. High use indoor pools can often benefit from supplemental oxidation from ozone or UV.

 

[Patrick_B]

We use the Taylor test kit, and we also use a photometer. Daily bather load is approximately 120 people. We also do a daily 10 minute backwash to help combat the high bather load. We have read that backwashing 8 gallons of water per bather, on a daily basis will help to combat the CC. We don't use Cyanuric acid, since we are an indoor pool. (We were told that Cyanuric acid is a stabilizer that is needed in outdoor pools only, because the sun causes the chlorine to break down.) Our city is also in the process of making the use fo cyanuric acid in pools illegal due it causing birth defects.

Interesting. That's the first I've heard of that regarding Cya. Not arguing merit to the argument or not, just haven't heard it yet.

 

[writingwizard]

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[jblizzle]

Please add your pool details to your signature and location to your profile as described HERE as it will help us help you.

I am really curious to see your location regarding that CYA statement.

A FC level of 1.5ppm with no CYA is pretty harsh ... that is an active chlorine level of ~0.7ppm Cl2.
We recommend the use of CYA for indoor pools as well, not for the protection from the sun, but for the buffering effect on the chlorine.
For example, with a CYA of 30ppm and our recommended FC target of 4ppm ... the active chlorine level is ~0.06ppm Cl2 ... that is 10 times less harsh than what you are currently running. Meaning what you have is 10x more drying of the skin and hair and damaging to swimwear than what we would recommend.

To match our recommended levels of active chlorine, you would have to keep the FC level around 0.15ppm ... and that is just not feasible to maintain or test for.

So, the irritation could be a combination of the drying effect of all the active chlorine and the higher than recommended CC levels (assuming they are not due to MPS) and the possible irritation due to the MPS itself.

 

[poolgurl88]

Hi there,
We operate a small, indoor, commercial pool, and we are struggling with bathers who complain of skin irritation and itching after prolonged exposure to the water. We use liquid sodium hypochlorite that is injected automatically by our Prominent Fluid Injection System. The fluid injection system also automatically regulates our pH by injecting muriatic acid. (We also manually test the water 3 times per day.) We do not use any cyanuric acid in our pool. We also do a daily enzyme treatment on the water using the Orenda enzymes. We have a high rate sand filter, and a 2 horsepower pump. Our free chlorine is consistently at 1.5 ppm, and our pH is kept at 7.4. Our combined chlorine is usually between .2 and .7. We do a weekly non-chlorine shock, using potassium monopersulfate. Our TDS is currently at 1300. Our pool is kept at 92 degrees, and we do have a high bather load.

Any ideas what could be causing the itching/irritation for our bathers? We are trying to be proactice with our pool maintenance, yet even when our numbers seem to be in range, it still seems that our water causes irritation. Any input is appreciated.

How old is the water? Tds is getting high but shouldn't be causing reactions. If your using an enzyme treatment and your water is set at 92 be weary and verify your enzyme capacity. Most enzymes are sluggish to work outside the operating temps. At my store we have one designed for spas and one for pools. I had a commercial customer who had problems but your already using a non chlorine shock. If your having problems though, you can use the mps more then once, especially in warmer water I have a customer who uses it daily

Sent from my SPH-L720 using Tapatalk

 

[Bama Rambler]

With a bather load that high in a small pool it's going to be problem keeping the irritating products down without some supplemental oxidation.

 

[duraleigh]

I have NEVER heard of ANYONE banning CYA for the reasons you state. What City, please?

 

[chem geek]

(We were told that Cyanuric acid is a stabilizer that is needed in outdoor pools only, because the sun causes the chlorine to break down.) Our city is also in the process of making the use fo cyanuric acid in pools illegal due it causing birth defects.

Why don't you tell whomever in your city is making this ridiculous recommendation that this paper which is probably the one that got them all in a tizzy is about melamine and cynauric acid combined. It is not about Cyanuric Acid by itself. CYA has been extensively tested for toxicity and you can read details in this report where it shows that CYA has lower toxicity than ordinary table salt (lethal dose is 7700 mg/kg compared to ordinary sodium chloride table salt at 3000 mg/kg -- lower numbers are more toxic) and has minimal dermal absorption. As for toxicity to reproduction, the No Observed Adverse Effect Limit (NOAEL) for rats is 600 mg/kg/day while for developmental toxicity/teratogenicity the NOAEL in rabbits is 200 mg/kg/day. A 50 kg (110 pound) female would have to drink 100 liters of 100 ppm CYA water every day to get to the lower of these limits and those are NOAEL so you'd still have no observed adverse effects. In other words, there is no risk for causing birth defects.

As for not having any CYA indoors because there is no sun, again those who make such statements don't understand chemistry. CYA is not only useful to protect chlorine from more rapid breakdown from the UV in sunlight, but it also significantly moderates chlorine's strength by having chlorine bind to it. For an indoor commercial/public pool, 4 ppm FC with 20 ppm CYA would be equivalent to roughly 0.2 ppm FC with no CYA. Your 1.5 ppm FC with no CYA is roughly 7.5 times higher in active chlorine concentration which oxidizes swimsuits, skin and hair that much faster, outgases faster, corrodes metal faster, etc. In effect, you are over-chlorinating. Note, however, that some states do (stupidly) ban CYA use in indoor commercial/public pools -- what state are you in?

 

[writingwizard]

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[RobbieH]

Just goes to show you can sue and win for anything, even if it doesn't make sense.

 

[duraleigh]

Can you link us to those lawsuits? Twice now you have definitively said CYA can cause birth defects so I assume those lawsuits proved that, right?

We all use CYA every day and have for years and have never heard of ANY harmful effects at appropriate levels.

Can you provide some legitimate documentation (not something a neighbor told you)?. If there is truth in what you are saying we would like to chime in to the discussion.

I know we've drifted off topic, but TFP is the leading residential pool water authority and it's important we keep up with all things pool chemistry related.

 

[Richard320]

We use the Taylor test kit, and we also use a photometer. Daily bather load is approximately 120 people. We also do a daily 10 minute backwash to help combat the high bather load. We have read that backwashing 8 gallons of water per bather, on a daily basis will help to combat the CC. We don't use Cyanuric acid, since we are an indoor pool. (We were told that Cyanuric acid is a stabilizer that is needed in outdoor pools only, because the sun causes the chlorine to break down.) Our city is also in the process of making the use fo cyanuric acid in pools illegal due it causing birth defects.

As others have mentioned, where did you hear that? The Pool Store?

I just hunted through the archives of the Las Vegas Review Journal and failed to see any news in the last year regarding Cyanuric Acid. http://www.reviewjournal.com/archive/search

Then I started delving into the Southern Nevada Health District website https://www.southernnevadahealthdistric ... /index.php but failed to see any prohibitions or cautions against cyanuric acid.

The state public health department site says this:

NAC?444.148??Quality of water. (NRS 439.200, 444.070)
1.??Water entering a public bathing or swimming facility for the first time must meet the bacteriological standards for potable water set forth in the primary drinking water standards adopted pursuant to NRS 445A.855, except the health authority may approve the use of water from natural sources including saline water. Fresh water must be added to pools that depend upon the flow of a stream, lake, well or other source which has been diverted to flow in and out of the pool, at a rate of not less than 1,000 gallons (378.5 liters) per hour for each 20 bathers using the pool during each hour.
2.??All public bathing or swimming facilities must have a uniform flow-through of water in the volume and quality described in subsection 1, or recirculation and filtration equipment provided for water purification in accordance with the requirements of NAC 444.010 to 444.306, inclusive.
3.??The equipment must provide water which meets the following standards:
(a)?The water must be continuously disinfected by a chemical which imparts an easily measured, freely available residual effect. Except as otherwise provided in NAC 444.207, adequate disinfection must be accomplished by one of the following:
(1)?Normal chlorination of 1.0 to 5.0 ppm chlorine at pH 7.0 to 8.0;
(2)?Chlorinated cyanurate chlorination of 1.0 to 5.0 ppm at pH 7.2 to 8.0; or
(3)?Normal bromination of 3.0 to 5.0 ppm at pH 7.0 to 8.0.
(b)?The health authority may accept other disinfecting materials or methods if they have been adequately demonstrated to provide a satisfactory residual effect which is easily measured, and otherwise to be equally as effective under conditions of use as the chlorine concentration required in this section.
(c)?The maximum permissible concentration of cyanuric acid is 100 ppm.
(d)?The total alkalinity should be within the range of 80 to 120 ppm.
4.??The chemical quality of water used in the facility must not cause irritation to the eyes or skin of the bathers, or have other objectionable physiological effects on bathers.
5.??The water must have sufficient clarity at all times so that the pattern of the main drain in any pool is clearly visible from the walk at the deep end. Failure to meet this requirement constitutes a ground for the immediate closing of the facility.
[Bd. of Health, Public Bathing Places Reg. Art. 20 §§ 20.1-20.5, eff. 5-21-74]—(NAC A 7-23-82; 11-1-88)

Emphasis added. http://www.leg.state.nv.us/nac/nac-444.html

As an aside, backwashing only dilutes the pool chemicals and removes sediments caught in the filter. Do you mean to say you dump almost a thousand gallons a day -- 8 gallons/bather * 120 bathers/day? That is hugely wasteful. The city doesn't care? What city is this?

 

[Patrick_B]

Thanks for the feedback everyone. We are in Southern Nevada. CYA is not banned yet here, but it soon will be. Several lawsuits have been won against casinos here that had CYA in their pools. The legislation to ban it has not been passed yet, but it soon will be, most likely. It is already banned in commercial pools in the state of New York, and there are other states that are working to ban it as well or to place a limit on the amount of CYA that is acceptable. This is due to it causing birth defects and also due to it causing the chlorine to become ineffective against crypto.

In the mean time, I will consider your argument for the buffering effect of CYA on our FC. Thanks for your input.

Cya does NOT make Chlorine ineffective against Crypto. It would be a a lack of enough FC to allow it to live.

 

[JamesW]

Writingwizard, can you provide references for any of the following:

1) Any reference that claims that cyanuric acid in pool water causes birth defects?
or
2) Any reference to anyone who has ever sued a pool operator claiming that the operator was liable for birth defects because the operator used cyanuric acid in a swimming pool?
or
3) Any government anywhere that has banned, or is considering banning, cyanuric acid because it causes birth defects?

Here is a reference that says the following

Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized.
http://www.iwaponline.com/jwh/004/0425/0040425.pdf
http://libra.msra.cn/Publication/644830 ... ilot-study

Reference cited for study:
Absorption and Excretion of Cyanuric Acid in Long-Distance Swimmers
http://informahealthcare.com/doi/abs/10 ... 8209029992

 

[chem geek]

Cya does NOT make Chlorine ineffective against Crypto. It would be a a lack of enough FC to allow it to live.

CYA reduces the active chlorine level so does make it less effective against Crypto, but normal FC levels without CYA are also ineffective against Crypto anyway. Chlorine alone won't kill Crypto quickly at all. The CT value is 15,300 (see this CDC link) so 1 ppm FC would take 10 days for a 99.9% kill of Crypto. If you wanted to hyperchlorinate to 10 ppm FC, then with CYA in the water you'd have to raise the FC to around 10 ppm higher than the CYA level so at higher CYA levels that can become impractical.

Nevertheless the CDC Model Aquatic Health Code (MAHC) is taking the approach of requiring supplemental UV or ozone to deal with Crypto. They initially were going to ban it in indoor pools and high-risk venues, but are reconsidering this at least for indoor pools as modest amounts of CYA can moderate chlorine's strength but not so much as to be ineffective.

I already linked to the references regarding birth defects having to do with melamine with cyanuric acid (that was also implicated in the pet food killing pets in the U.S. and in babies dying in China). This has nothing to do with cyanuric acid alone. Again, stop the scaremongering. As for lawsuits, please give specific links or details to them. Lawsuits are scientific proof, but it would be good to look at the trial transcripts to see what was actually claimed or said.

As for New York, it is the only state in the nation banning CYA, but that was because they did not understand that hyperchlorination with chlorine is still possible if the CYA level isn't too high and that the active chlorine level can be too high when there is no CYA.

 

[Patrick_B]

Thanks for clearing me up on that Richard. I'm thinking of something else, but obviously wrong on this point.

 

[duraleigh]

writingwizard,

As you can see from the responses about CYA, people on this forum deal with logic and facts and science.

I realize you did not post to talk about CYA but it is important we all get on the same page if we are to help you solve your bather irritation issue.

We can do that but CYA is going to be a suggested part of the best remedy.