Describes a method of determining the force required to tear a specified distance from a specified slit, cut in a test specimen of thin flexible plastic sheeting or film, under specified conditions of loading. Includes flexible poly(vinyl chloride) and polyolefin films, but variable elongation and oblique tearing effects on the more extensible films may cause poor reproducibility of test results. May not be suitable for testing more rigid materials such as rigid PVC, nylon and polyester films. Suitable for the control of production and manufactured products. Covers references, definition, principle, apparatus, test specimens, conditioning, procedure, calculation and expression of results and test report.