The procedure to predict to time to crack initiation and rupture of rubber sheets by ozone is described. Five kinds of rubber sheets were exposed in the air for three years at Yokohama, measuring ozone concentration and temperature of the specimens every 10 minute. The time to the failure of each sheet was calculated by the proposed method, using both the measured data, and were compared with the exposure test results. The predicted times approximately agreed with the test results, and the proposed method was considered to be applicable to estimate the ozone degradation of the rubber sheets exposed in the air.
