The reaction of ozone with ethane was studied in the range 24-150 degrees C. Added oxygen at 24 degrees C was found to cause a large induction period after which the reaction occurred rapidly accompanied by a flash of light. The light consisted of Meinel bands from vibrationally excited OH radicals as had been previously seen at higher temperatures in the methane-ozone system. Induction periods of more than 3 h were measured when an excess of oxygen was added. Total pressure measurements suggested a chain reaction, and several possible chain sequences are considered. A 42-step mechanism was used to simulate the system and found to account for the effect of added oxygen on the induction period and on the light emission.