ISO 22088-3:2006 specifies a method for the determination of the environmental stress cracking (ESC) resistance of thermoplastics when they are subjected to a fixed flexural strain in the presence of chemical agents. ESC is indicated by the change of a suitably chosen indicative property of specimens that have been strained for a defined time in the environment. The method of test is suitable for determining the resistance of sheets and of flat test specimens, especially the sensitivity of localized surface regions of specimens, to ESC. This is essentially a ranking test and is not intended to provide data to be used for design or performance prediction. For a constant strain test, refer to ISO 22088-5. For a constant load test, refer to ISO 22088-2.