Electrolysed Water (also known as "Electrolyzed Oxidizing Water" EOW, Electro activated water (EAW) or Electro-chemically activated water (ECA or ECAW) solution) is produced by the electrolysis of ordinary tap water containing dissolved salt sodium chloride. This occurs in a specially designed reactor which allows the separation of the cathodic and anodic solutions. In this process, hydrogen gas and hydroxide ions are produced at the cathode, leading to an alkaline solution that consists essentially of sodium hydroxide NaOH. At the anode, chloride ions are oxidized to elemental chlorine. If some of this chlorine is allowed to combine with some of the hydroxide ions produced at the cathode, it disproportionates into hypochlorous acid HOCl, a weak acid and an oxidizing agent. This "acidic electrolyzed water" can be raised in pH by mixing in the desired amount of hydroxide ion solution from the cathode compartment, yielding a solution of sodium hypochlorite NaOCl which is the major component of ordinary household laundry bleach. A solution whose pH is 7.3 will contain equal concentrations of hypochlorous acid and hypochlorite ion; reducing the pH will shift the balance toward the acid.
Both of these species are efficient disinfecting agents; since relatively few microorganisms can tolerate acidic conditions, the acidic form of EOW is usually preferred for rinsing food-preparation surfaces, fruits and vegetables. Preparations sold for topical application to wounds are usually slightly alkaline.
Sodium hypochlorite is produced in large quantities as a byproduct of the manufacture of chlorine and its solutions are widely available as household laundry bleaches. Mixing a dilute acid such as vinegar or lemon juice with a dilute solution of laundry bleach and adjusting the pH to around 4-5 will yield a solution roughly equivalent to that produced by EOW "machines" whose capital and operating costs may not be justified if only small quantities of EOW are required.
Some promotions of EOW claim that it can act as an antioxidant food additive; however, both of the chlorine-containing components of EOW are active chemical oxidizing agents.[1]
^ Callaway, Chyi-Shen; Wu, Christ; Yeh, Jui-Yueh; Saalia, Firibu K. (2005). "The evaluation of electrolysed water as an agent for reducing micro-organisms on vegetables". International Journal of Food Science and Technology40: 495–500. Retrieved on 2007-01-10.
