TriChlor, CYA, and Disinfection...Help Me Understand

[CYAppm]

Can TriChlor be used as a disinfectant outside of the pool ,i.e., dissolving 1" or 3" tablets in water and using it to disinfect surfaces. My inclination is no because the CYA levels would be too high thereby disrupting the chlorine's ability to kill certain viruses.

The reason I ask is because my new employer is using TriChlor tablets as a substitute for liquid bleach in the disinfection of surfaces contaminated with human feces, blood, vomit, etc. Based on my research I don't believe TriChlor tablets work as effectively as a solution of concentrated liquid bleach because of the CYA.

I know this is not exactly a pool related question, but I think this forum is the only place on the internet with the knowledge to answer my question. Please help... I'm concerned about the safety of our employees and the public that uses our facilities.

Thank you,
Daniel

 

[JoyfulNoise]

I would say that your analysis is mostly correct. Trichlor does not make a good contact disinfectant because the CYA slows the disinfection rates down. Bleach solutions make the best disinfectants because the concentration of hypochlorous acid is so high that contact times only need to be very short in order for it to kill or inactivate most pathogens.

However, there are other reasons not to use trichlor in this manner as it is highly acidic and can damage sensitive surfaces such as metals and soft stone surfaces. As well, when trichlor tablets get wet and are left in air, they can emit quite a lot of chlorine gas. That is dangerous to the people working in and around it.

Only you can determine if you feel that your working environment is unsafe and you have every right to report an unsafe work condition through the proper channels at your employer. Good luck.

 

[CYAppm]

Thanks for the reply. I'm going to talk about it with my supervisor. He thinks the Trichlor tabs are "90% chlorine". I think hes confused by the available or free chlorine (which I don't completely understand yet), but from what I've read the tablets are ~50% CYA by weight.

Thankfully liquid bleach is cheap so I don't see why it would be a big deal for us to purchase a few boxes of bleach.

 

[JoyfulNoise]

If he wanted to use a powdered source of chlorine that would be highly effective, he should just use cal-hypo powder instead. It's called "bleaching powder" for a reason - it was originally used as laundry bleach because liquid bleach based on sodium hypochlorite was not easy to get and store. In the good ole days, people used bleaching powder for cleaning and disinfecting. It much easier to sprinkle a little powder from a 1 lb bag of cal-hypo than lug around a 4 lb jug of liquid bleach.

Available chlorine is just the measure of the concentration of chlorine in something as chlorine gas. So when the trichlor say 91% available chlorine that just a way of comparing it to other chlorine source like bleach (8.25% sodium hypochlorite is approximately 7.8% available chlorine). So yes, a trichlor tablet is more highly concentrated in chlorine than a bottle of bleach BUT the acidity of the trichlor and the presence of CYA makes it less effective in the application as a disinfecting cleanser.

 

[Patrick_B]

It would be better, safer, and certainly more practical to simply mix a diluted bleach solution. His method simply isn't the best approach for more than one reason.

Edit: My reply was intended for an answer to post #3 and not a rebuttal of Matt's last reply. As usual... too slow.

:sad:

 

[CYAppm]

The reason we have the TriChlor tablets is because we use them to treat large ~2000 gallon water tanks fed by local springs; the tanks feed faucets and spigots used by the public. Again... not the intended use for these tablets.

Since we have the tablets available my smart management folks figure we can kill two birds with one stone and use them as disinfectant too.

 

[jblizzle]

You should not be offering water for consumption that contains CYA. This employer sounds like a train wreck.

 

[domct203]

The reason we have the TriChlor tablets is because we use them to treat large ~2000 gallon water tanks fed by local springs; the tanks feed faucets and spigots used by the public. Again... not the intended use for these tablets.

Since we have the tablets available my smart management folks figure we can kill two birds with one stone and use them as disinfectant too.

Oh my.... These are some serious heath code issues.... The CYA from those tabs is going to build up to levels that will make sanitation ineffective..... Someone is going to get sick from the water and/or contaminated surfaces, not to mention the possible consumption of high levels of CYA. Definitely bring this to the employers attention before someone gets seriously ill, or god forbid, worse.

 

[Patrick_B]

No, this will not do. You must use an approved drinking water sanitizer. In Texas this is regulated by the TCEQ. We are a reciprocity state meeting or exceeding EPA drinking water regulations. Different brands of Bleach, and pure gaseous Chlorine are at least two approved sanitizers on the list. They need to look into legal drinking water requirements if they are providing water for public use or consumption. Period.

I think we have offered all we can on this, and I am closing the thread.