FAQs

General information

Hypochlorous acid (HOCl) is a weak acid, formed from the reaction of chlorine with water. In addition to its use as a reagent in organic chemistry, it has significant biological relevance. HOCl is generated in biological systems in a reaction between chloride ions and hydrogen peroxide, catalysed by the enzyme myeloperoxidase.

This enzyme is secreted by phagocytes (cells which help protect the body by ‘ingesting’ bacteria) when they are activated during an immune response. Hypochlorite (ClO), the conjugate base of HOCl, is extremely toxic to bacteria and plays a vital role in assisting the activated phagocytes with killing a wide range of pathogens.

How safe is HOCL - Hypochlorous Acid ?

Hypochlorous acid is non-toxic and non-hazardous. Unlike most chemical sanitizers, hypochlorous acid is non-irritant to eyes, skin, and the respiratory tract. Even if it were ingested by accident, it causes no harm.

Can HOCL - Hypochlorous Acid be used directly on food ?

Yes, the majority of the research on hypochlorous acid has been for using hypochlorous acid directly on food. The FDA Food Contact Notification 1811 allows for hypochlorous acid to be used on raw or processed fruits & vegetables, fish & seafood, meat, poultry and shell eggs at up to 60 ppm.

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How effective is HOCL - Hypochlorous Acid killing viruses?

Hypochlorous acid (HOCl) has been researched and proven to be effective against many viruses.

Study 1 - Evaluation of Virucidal Efficacy on Surface by EcoloxTech Hypochlorous Acid Solution (pH 8) against Murine Norovirus (Surrogate for Human Norovirus)

Microbe(s): Murine Norovirus surrogate for Human Norovirus


The EcoloxTech 240 system was used to generate a 50 ppm electrolyzed water solution of hypochlorous acid at pH 8 (25% solution of HOCl). Ceramic tile which had been innoculated with Murine Norovirus was treated with the hypochlorous acid solution for a contact time of 1 minute resulting in a 4-log reduction of Murine Norovirus.

Study 2 - Evaluation of Virucidal Efficacy on Surface by EcoloxTech Hypochlorous Acid Solution (pH 5) against Murine Norovirus (Surrogate for Human Norovirus)

Microbe(s): Murine Norovirus surrogate for Human Norovirus


The EcoloxTech 240 system was used to generate a 50 ppm electrolyzed water solution of hypochlorous acid at pH 5 (99% solution of HOCl). Ceramic tile which had been innoculated with Murine Norovirus was treated with the hypochlorous acid solution for a contact time of 1 minute resulting in a 5-log reduction of Murine Norovirus.


The advent of old diseases in new places, of newly-emerging infectious diseases not seen before, and of highly resistant organisms, has complicated disaster response and the management of displaced populations. One method for addressing that developing risk is to attack pathogens before they become life-threatening infections using area and wound decontamination and disinfection techniques. Current methods for disinfection, however, can contribute to the development of resistance, prove toxic to...

How effective is HOCL - Hypochlorous Acid killing bacterial?

Chlorine is an extremely effective disinfectant for inactivating bacteria. A study conducted during the 1940s investigated the inactivation levels as a function of time for E. coli, Pseudomonas aeruginosa, Salmonella typhi, and Shigella dysenteriae (Butterfield et al., 1943). Study results indicated that HOCl is more effective than OCl- (aka. chlorine bleach) for inactivation of these bacteria. These results have been confirmed by several researchers that concluded that HOCl is 70 to 80 times more effective than OCl- for inactivating bacteria (Culp/Wesner/Culp, 1986). Since 1986, there have been hundreds of publications confirming the superiority of HOCl over OCl- (click here to visit research database). HOCl may be more effective than OCl- for two reasons, this first is because it holds a neutral charge and therefore can easily penetrate the negatively charged cell walls of bacteria. The second reason is because HOCl has a much higher oxidation potential than OCl-.

Does HOCL - Hypochlorous Acid kills biofilm?

Yes, hypochlorous acid is very effective at removing biofilm and preventing formation.

How dose HOCL kills viruses & bacterial?

Hypochlorous acid (HOCl) is a neutrally charged molecule. Bacteria have negatively charged cell walls. Just like magnets, molecules with the same charge will repel each other. For example, the negatively charged molecule of bleach (OCl-) is repelled by bacterial cell walls. This is not the case with HOCl which is neutrally charged. HOCl easily penetrates bacterial cell walls. HOCl either oxidizes the cell walls killing the bacteria or enters through the cell walls and destroys the vital components inside the bacteria.

Is there any adverse effect or disadvantages ?

Unlike many other sanitation chemicals, hypochlorous acid does not have an ongoing antimicrobial effect. In other words, once it lands on a surface, it reacts with any germs or organic matter on that surface and then immediately deactivates. This is good and bad. It is good because it allows for sanitation without requiring a post-rinse because no toxic chemicals are left behind. The disadvantage is that it has to be continuously applied.

What is HOCL - Hypochlorous Acid?

Hypochlorous acid is a free chlorine molecule with the chemical structure HOCl. It is the dominate free chlorine species in chlorine solutions that have a slightly acidic to neutral pH. HOCl is a much more powerful oxidant than sodium hypochlorite (or chlorine bleach).

How is generated in nature?

Hypochlorous acid is produced naturally by the white blood cells of all mammals. It is used by white blood cells to kill invading microbial pathogens.

Stability & Production

How HOCL - Hypochlorous Acid is made ?

Hypochlorous acid is made through a process called electrolysis. By passing a sodium chloride solution (NaCl) through an electrolysis cell containing an anode and a cathode, electrolyzed water is generated. There are two commonly used electrolysis methods for generating hypochlorous acid, membrane cell electrolysis and single cell electrolysis. Membrane cell electrolysis converts a saltwater brine into two solutions, a strongly acidic anolyte of hypochlorous acid and a strongly alkaline catholyte of sodium hydroxide. Single cell electrolysis converts a saltwater brine into one solution, a slightly acidic-to-neutral anolyte of hypochlorous acid.

Is HOCL - Hypochlorous Acid stable?

Depending on the process used to generate the hypochlorous acid, the solution can be stable. Membrane cell electrolysis generates two streams with opposing oxidation-reduction potentials and opposite pH. This is done by forcing positively charged sodium ions across a membrane toward the cathode side. On the anode side, a very high concentration of anolyte is generated that is strongly acidic (~ pH 3). Generating hypochlorous acid by this method is not as stable as that generated by single cell technology. Single cell technology uses an acidified brine and only one stream of solution is generated in the pH range of 5-7. When generating hypochlorous acid through a single cell, no high pressures are used and no ions are forced across a membrane. The hypochlorous acid generated is stable, not seeking a new equilibrium like the anolyte generated from membrane cell systems.

What is HOCL - Hypochlorous Acid shelf life?

The shelf-life can be 3-6 months if stored in a closed container protected from the oxygen in the air. Containers that block out UV light may have a small effect on extending shelf-life.

What concentration of HOCL - Hypochlorous Acid should be used?

The concentration that should be used depends on the application. Sanitizing food such as fruits & vegetables and fish & seafood is highly effective at 20-30 ppm however the FDA allows concentrations to be used as high as 60 ppm without requiring a post rinse. Sanitizing food contact surfaces is also effective at 20-30 ppm however concentrations as high as 200 ppm are allowed by the FDA. Water disinfection is effective at 1-2 ppm however the EPA allows up to 4 ppm. When deciding what concentration to use, it is best to refer to the research. Over 300 research articles have been published covering nearly every application. Click here for detail research

How concentration HOCL - Hypochlorous Acid is measured ?

Hypochlorous acid is measured with the same standard test strips that measure free chlorine in a pool. The test strips will turn a different shade of purple to indicate the concentration between 10 and 200 ppm. For higher concentrations, the solution being tested can be diluted. (Example: A 1000 ppm solution could be diluted at a 1:10 ratio. A test strip would then read 100 ppm indicating the original solution was 1000 ppm.)

Does Does HOCL - Hypochlorous Acid kills Listeria, Salmonella, and E. coli?

Yes, probably the most research on hypochlorous acid has been done on the microbial pathogens Listeria, Salmonella, and E. coli.

Does Does HOCL - Hypochlorous Acid effective against Norovirus?

Yes, there are two published studies on Norovirus. Click here to see the research on Norovirus.

EcoloxTech Norovirus Research - Study 1

Study 1 - Evaluation of Virucidal Efficacy on Surface by EcoloxTech Hypochlorous Acid Solution (pH 8) against Murine Norovirus (Surrogate for Human Norovirus)

Microbe(s): Murine Norovirus surrogate for Human Norovirus


The EcoloxTech 240 system was used to generate a 50 ppm electrolyzed water solution of hypochlorous acid at pH 8 (25% solution of HOCl). Ceramic tile which had been innoculated with Murine Norovirus was treated with the hypochlorous acid solution for a contact time of 1 minute resulting in a 4-log reduction of Murine Norovirus.


EcoloxTech Norovirus Research - Study 2

Study 2 - Evaluation of Virucidal Efficacy on Surface by EcoloxTech Hypochlorous Acid Solution (pH 5) against Murine Norovirus (Surrogate for Human Norovirus)

Microbe(s): Murine Norovirus surrogate for Human Norovirus


The EcoloxTech 240 system was used to generate a 50 ppm electrolyzed water solution of hypochlorous acid at pH 5 (99% solution of HOCl). Ceramic tile which had been innoculated with Murine Norovirus was treated with the hypochlorous acid solution for a contact time of 1 minute resulting in a 5-log reduction of Murine Norovirus.

Journal of Food Protection 78.6 (2015): 1147-1153

Comparative study on the efficacy of bacteriophages, sanitizers, and UV light treatments to control Listeria monocytogenes on sliced mushrooms (Agaricus bisporus)

Microbe(s): MNV-1, Norovirus, HAV, Hepatitis A


The ability of acidic electrolyzed oxidizing water (AEO) and neutral electrolyzed oxidizing water (NEO) to inactivate the murine norovirus (MNV-1) surrogate for human norovirus and hepatitis A virus (HAV) in suspension and on stainless steel coupons in the presence of organic matter was investigated. Viruses containing tryptone (0.0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0) were mixed with AEO and NEO for 1 min. In addition, stainless steel coupons containing MNV-1 with or without organic matter were tr...




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