Refers to tests with a definite temperature under static tensile strain with air containing a definite concentration of ozone in circumstances that exclude the effects of direct light. Great caution is necessary in attempting to relate the test results to service performance. Explanatory notes on the nature of ozone cracking are given in Annex A. Part 2 refers to dynamic tensile strain. Constitutes technical revision of the second edition (ISO 1431-1:1980).