What is HOCl?
QUICK FACTS
HOCl is the scientific formula for hypochlorous acid, a weak acid similar to that of a mild citrus juice.
How is HOCl made?
HISTORY OF ELECTROLYSIS
Michael Faraday founded the laws of electrolysis and it became commercially available in the 1870s.
Research Publications
RESEARCH BY MICROBIAL PATHOGEN
Listeria - Over 70 Research Publications
E. coli O157:H7 - Over 60 Research Publications
Why is HOCl more efficient at killing pathogens?
Hypochlorous Acid (HOCl) vs. Sodium Hypochlorite (Chlorine Bleach)
Home use of HOCl
There are several home electrolysis systems that have been developed that can generate stable hypochlorous acid using table salt and water. Distilled vinegar is sometimes added to lower the pH allowing for a solution of free chlorine more dominated by the hypochlorous acid molecule. When choosing a home system, an important factor to consider is the quality of the electrolysis cell. Higher quality systems may cost more but will last much longer due to the durability of the alloys in the metals used to make the cells.
Hypochlorous acid, unlike chlorine bleach, is 100% safe and non-irritant. If it gets on your skin or in your eyes, it will not burn. Even if it were accidentally ingested, it is completely harmless. Yet, it is 70-80 times more efficient at killing microbial pathogens than chlorine bleach.
In the home, hypochlorous acid is useful anywhere you need a sanitizer but don’t feel comfortable using a toxic chemical. A perfect example is in the kitchen. Instead of rinsing leafy greens with water, use hypochlorous acid. Or for pesonal items such as toothbrushes or razors, hypochlorous acid is safe. Want to sanitize laundry without damaging or discoloring clothing, hypochlorous acid is the answer.
Commercial use of HOCl
The technology behind generating hypochlorous acid has evolved tremendously over the past 20 years. The market used to be dominated by membrane cell electrolysis that used high pressures to force saltwater into two separate streams, an acidic stream and an alkaline stream. The acidic stream would contain hypochlorous acid (HOCl), the anolyte or oxidizing agent, and the alkaline stream would contain sodium hydorixde (NaOH), the catholyte or reducing agent. The benefit of these systems were that two useful solutions were generated, a sanitizer and a degreaser. The downside of these systems were that they were expensive, required high maintenance, and would generate unstable solutions that lost their oxidation-reduction potential (ORP) within a short period of time.
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.
Food Safety
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.
Surface Sanitation
Hypochlorous Acid vs. Quaternary Ammonium (Quats)
Hypochlorous acid has advantages over chemicals such as Quats when sanitizing food contact surfaces because Quats are not safe on food. Before cleaning with Quats, all food must be removed from the area before sanitation can take place. This is not required when using hypochlorous acid. Hypochlorous acid can be used continuously throughout the work day regardless of whether food is exposed.
Direct Food Sanitation
Hypochlorous Acid vs. Ozone
Hypochlorous acid has advantages over ozone. Ozone is a gas and is not stable in solution therefore it cannot be used to sanitize contact surfaces. Ozone is however used for food sanitation however it must continuously be regenerated as it is continuously leaving solution into the air. Being that ozone is an irritant to the lungs and respiratory tracts, ozone is limited in the concentrations that can be used, therefore limiting the oxidation potential that can be obtained for killing microbial pathogens. Hypochlorous acid is non-irritant and is also stable in solution. Hypochlorous acid can be used at high concentrations (60 ppm) for food sanitation without requring a post-rinse.