Electrolysis Technology - Generating Hypochlorous Acid (HOCl)
Invention of Electrolysis
Electrolysis is the passing of a direct electric current through an ionic substance. It was first explained by Michael Faraday in the 1830s.
Membrane electrolysis generates strongly acidic HOCl and an alkaline byproduct of NaOH from a solution of NaCl (aka. table salt in water).
Single Cell Electrolysis
Single cell technology was developed to generate a more stable solution of HOCl at an optimal pH without an alkaline byproduct of NaOH.
Stable Hypochlorous Acid
This biggest challenge has been to create hypochlorous acid at a near neutral pH instead of chlorine gas or hypochlorite, and to do so in a stable form. Hypochlorous acid is a meta-stable molecule. It wants to revert back to salt water or convert to hypochlorite.
Generating Stable Hypochlorous Acid
Membrane Cell Technology
The electrolysis cell has two compartments separated by a membrane, an anode compartment and a cathode compartment. The membrane is made from a polymer which only allows positive ions to pass through it toward the cathode compartment. A sodium chloride solution is injected into the anode compartment. The positively charged sodium ions pass through the membrane to the cathode side but the negatively charged chloride ions do not.
Two solutions are generated, an anolyte and a catholyte. On the anode side, a solution of hypochlorous acid is generated that is strongly acidic and with an ORP > 800 mV. On the cathode side, a solution of NaOH is generated that is strongly alkaline and with an ORP < -800. Neither solution generated is stable. Both the anolyte and catholyte seek to return to an equilibrium. Both solutions rapidly lose their ORP.
Single Cell Technology
With the development of single cell electrolysis, many of these obstacles were overcome. Single cell electrolysis does not use high pressures across a membrane therefore little to no maintenance is required. And because single cell electrolysis does not force the saltwater into two streams of opposite oxidation-reduction potential and opposite pH, a more stable solution is generated, a solution that is not seeking to regain an equilibrium. Single cell systems generate only one solution, an anolyte in the pH range of 5 to 7. This pH range is optimal for hypochlorous acid in regards to stability and effectiveness as a sanitizer.
Hypochlorous acid (HOCl) is already produced by the white blood cells in our blood for protecting against invading microbial pathogens. When microbial pathogens try to enter a wound, white blood cells are the first responders and engulf the bacteria exposing them to the biocide HOCl. Because HOCl is non-irritant and gentle on skin, it makes sense to use it for wound care. In addition, it can replace all general sanitation chemicals used to clean healthcare facilities. Eliminating toxic chemicals not only makes sense but provides a safer environment for children and the elderly.
The majority of the research that has been done regarding the practical applications of hypochlorous acid has been in the field of food safety. Since the Food Safety Modernization Act (FSMA) was signed into law in 2011, the focus of food safety has shifted from responding to contamination to preventing it. There is probably no food sanitizer more researched and more understood than hypochlorous acid. The research clearly demonstrates that hypochlorous acid is safe and efficient for ensuring microbial counts are maintained below infectious levels on food and contact surfaces.