The oxidation potentials of common oxidants and disinfectants associated with water and wastewater treatment are all of a lower oxidation potential than ozone. There is only one element with a higher oxidation potential than ozone and that is fluorine. Organic compounds treated with a powerful oxidant as ozone will not always be converted totally to carbon dioxide and water, especially under abnormal industrial wastewater conditions. Ozone is very safe - in over 100 years of use, there has never been a fatal accident. While chlorine forms thousands of extremely toxic by-products, ozone forms virtually none.
Ozone is generated electrically and therefore adds no chemicals into the treated water.