Hypochlorous acid is naturally produced by the white blood cells of all mammals. It plays an important role in the immune system killing pathogens through oxidation and chlorination.
Hypochlorous acid can also be produced through a process called electrolysis. Electrolysis is a technique that uses a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Specifically engineered electrolysis cells can generate a solution of free chlorine species by running electricity through NaCl (table salt) and water. The oxidants hypochlorous acid (HOCl) and hypochlorite (OCl-) are formed at the anode. If the pH of the solution is weakly acidic to neutral, the free chlorine solution will be dominated by hypochlorous acid.
Hypochlorous is a powerful oxidant and is 100 times more efficient at killing microbial pathogens than sodium hypochlorite (aka. chlorine bleach).