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Electrolyzed Water

What is electrolyzed water, and is it allowed for organic processing?

By Daniel Nguyen

Electrolyzed water, sometimes referred to as electrolyzed oxidizing water (EO water), is a sanitizing solution conventionally used to reduce microbial contamination on both food contact and non-food contact surfaces. Unlike many other commercial sanitizers, electrolyzed water solutions are usually generated on-site with specially designed electrolyzed water generating devices. 

An electrolyzed water solution is generated by applying an electrical current to a solution of table salt (sodium chloride) dissolved in water. The resulting solution can be acidic, neutral or basic depending on the design of the specific generating device, and it contains an equilibrium of hypochlorous acid and hypochlorite ions. It is the presence of hypochlorous acid and hypochlorite ions that gives electrolyzed water solutions many of their sanitizing properties. 

Hypochlorous acid and hypochlorite ions are also the source of sanitizing properties for many other commercial products. Calcium hypochlorite and sodium hypochlorite, the active ingredients in bleach and water treatment tablets, dissociate when added to water. The resulting solutions contain a cation (the calcium or the sodium ion) and an equilibrium of hypochlorous acid and hypochlorite ions. 

The USDA organic standards at §205.605(b) currently allow chlorine materials in or on processed organic foods at with the annotation “[for] disinfecting and sanitizing food contact surfaces, Except, That, residual chlorine levels in the water shall not exceed the maximum residual disinfectant limit under the Safe Drinking Water Act (Calcium hypochlorite; Chlorine dioxide, and Sodium hypochlorite).” On September 11, 2015, the National Organic Program (NOP) published Policy Memo 15-4  to clarify that electrolyzed water is a type of chlorine material that is allowed in organic production and handling. In the memo, the NOP specified that hypochlorous acid, the active ingredient in electrolyzed water, is an allowable type of chlorine material. 

Revised and updated in June 2018 by OMRI Technical Director Johanna Mirenda. This article was originally published in the Summer 2014 edition of the OMRI Materials Review newsletter.