[FloatMan]

I've registered to this forum for help. I'm not a chemist or a chemistry student. I own and operate a commercial float tank center (aka sensory deprivation tank) and now, in the COVID world, we are stepping up our disinfection game.

Background: A float tanks contains 200-300 gallons of a solution of water and Epsom salt (magnesium sulfate) at a density of about 1.3, maintained at a temperature of about 94.5 f.  The water itself is kept safe through a combination of filtration between sessions, UV purification between sessions, and by maintaining 50 ppm hydrogen peroxide in the solution. We check this level twice daily and add 34% hydrogen peroxide as needed. Typically 2oz are added in the morning and 2 in the evening.

In light of the pandemic, we will begin disinfecting, among many other places, the hard, non-porous interior surfaces of the float tanks between clients. We need a disinfectant that can be applied and not wiped down, as it is not practical to enter each float tank after it is used. The substance used has to be harmless to the people who apply it and has to be safe when combined with the float tank solution (water and magnesium sulfate). 

We are looking at using hypochlorous acid at 500ppm as our disinfectant for the inside of the float tank. We can make it on site with a home product (https://store.ecoloxtech.com/ecoone). Hypochlorous acid is on the EPA's list of substances approved for "emerging pathogens", so we know it will be effective.  It is very benign stuff - can be sprayed on produce and on commercial food prep surfaces without rinsing.  My question is: Is it safe in combination with the float tank solution?  A colleague in the float industry said he believes mixing hydrogen peroxide and hypochlorous acid will produce hydrochloric acid, which I know is very caustic and dangerous. I just (cautiously and out of doors) mixed 3% hydrogen peroxide with the 500ppm hypochlorous acid and observed no response at all. No bubbling. No smell. It didn't hurt my skin to touch it. 

Please forgive my amateurish attempts to discuss a subject in which I have no expertise. I want to make sure that my staff and I are safe in our work - and that our customers are safe from infection.  Any help would be greatly appreciated!

[chenbeier]

Dont worry you can nix it in die concentration you asked. Nothing strange will happen.

[Enthalpy]

If you have to add hydrogen peroxide regularly, couldn't you use peroxide to clean the surfaces, and add correspondingly less peroxide daily to the tank?

[FloatMan]

Thanks. We have decided to do exactly that - use a 1% solution of H2O2 as a surface disinfectant. Our hesitation had been some corrosion of a few metal parts when we used 3% H2O2 to disinfect for about a week at the beginning of the pandemic before we decided to close down. I'm hopeful that the 1% solution will not cause as much corrosion.  We'll look at coating metal surfaces if it does - or look at switching to hypochlorous acid.