It has been postulated that ozone, like ionizing radiation, exerts its major oxidative effects on biological tissue via a free radical mechanism(s). Therefore, ozone has been considered a “radiomimetic” agent (Jaffe 1967; Veninga 1967; Zelac et a1. 1971). Jaffe (1967) has shown ozone to be lethal to small laboratory animals exposed to concentrations of 3.6 to 20 ppm within several hours, and to cause an increase in the mortality rate of animals exposed to 0.01 to 0.25 ppm ozone for several weeks.