What is ozone? Ozone is three atoms of oxygen combined in one molecule, or O3, whereas ordinary oxygen is two atoms of oxygen in each molecule, or O2. Most of us are familiar with ozone as it forms a protective layer around the earth and absorbs most of the sun's damaging ultraviolet radiation. The medical use of ozone dates back to the 19th century and was used as a disinfectant for wounds. Throughout the years, ozone has been used to treat a diverse array of infections as