Water Chlorine Check

Specialties Urology

Published

This is probably a biomed question, but what's the risk of checking the chlorine before the RO has ran for 15 min? Is it possibly getting a false positive and having to do the check again, or getting a false negative and killing all the patients? Or some other reason?

Specializes in Dialysis.

It would be a real positive as the carbon tanks wouldn't have had enough time to remove the chloramines from the city water. The carbon removes chloramines by adsorption and each tank requires at least 5 minutes to achieve this. A two tank system would be 10 minutes. AAMI standard is 15 minutes of rinsing before testing.

If it's positive and early then it is a true positive, but still not an accurate result. That was my reasoning for calling it a false positive. But a negative, even if it's a little early, should be accurate?

DISCLAIMER: This is only to understand why we do what we do, not advocating violating any policy!!

Specializes in Dialysis.

If the strip shows greater than 0.01 for chloramine then it's positive and a risk to run a treatment. As to whether you obtain that result 2 minutes or twenty minutes into rinsing, the patient still can't be run. I've seen r/o's test positve after 6 hours if biomed has run disinfectant. Alot of factors affect the rinsing process, the temperature of the water, water pressure in the line, how old the carbon in the tanks and when they were last replaced. There is too much "hurry up" in the dialysis world and that mind set leads to short cuts that endanger the patient. I've learned to do other things while my r/o is rinsing, string the machine, read the chart, assess the patient. But if you test negative before the 15 minute rinse is complete it would be safe to run the patient but against every policy I am familiar with and against AAMI standards. Why risk it?

Well said, Chisca, thanks for the input. You have satisfied my curiosity, not that I could ever put it in practice. Unfortunatly I have never been able to get from RO on to water test within 15 min anyway. But I do have a couple of questions:

If the strip shows greater than 0.01 for chloramine then it's positive and a risk to run a treatment

Did you mean 0.1, the AAMI standard?

I've seen r/o's test positve after 6 hours if biomed has run disinfectant.

What are you testing at the RO sample port? We check for chlorine between the tanks on city water, disinfecting the loop would have no impact on pre RO water.

Specializes in Dialysis.

Yes, 0.1 is the standard. The disinfectant was used on a portable r/o and tested positive at S1 after 6 hours of rinsing. I would think your pre r/o water would be positive too depending on how much chlorine your city uses.

The disinfectant was used on a portable r/o and tested positive at S1 after 6 hours of rinsing

I assume your S1 is between the tanks? If disinfectant is getting into your carbon tanks or anywhere pre RO you have a serious piping problem.

Specializes in Dialysis.

My biomed person isn't here today but I'll ask them. I do know that once a month a chemical called mincare is instilled and recirculated through the portable r/o's we use. Our tech is of the opinion that the mincare would destroy the carbon bed if it came into contact with the disinfectant. Interesting. I'll post up what our biomed has to say.

Interested to hear what your biomed says. I would tend to agree with your tech, but I would say deplete rather than destroy. Either way, not good.

Specializes in Dialysis.

Had a chance to talk with our biomed guy and Minncare, a disinfectant, is placed in the water loop downstream of the two carbon tanks. A positive chlorine at either S1 or S2 reflects the functioning of the carbon tanks and he wouldn't commit to either destroy or deplete as an adjective if they came into contact with the disinfectant, his words- "it would be a bad thing". I love it when they use complicated descriptions.

We're only clinical, they don't want to confuse us with big words.

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