This International Standard specifies a method for 3.2 failure: Unless otherwise specified in the product Standard, shattering or any Crack or Split on the inside of the pipe that was caused by the impact determining the resistance to external blows of ther- and that tan be seen by the naked eye (lighting moplastic pipes of circular Cross-section; it is called devices may be used to assist in examining the the staircase method. specimens). This method is applicable to isolated batches of pipe to be tested at 0 “C.