5.1 This test method establishes the temperature at which 50 % of the specimens tested would probably fail when subjected to the conditions specified herein. The test provides for the evaluation of long-time effects such as crystallization, or those effects that are introduced by low-temperature incompatibility of plasticizers in the material under test. Plastics and elastomers are used in many applications requiring low-temperature flexing with or without impact. Use data obtained by this method to predict the behavior of plastic and elastomeric materials at low temperatures only in applications in which the conditions of deformation are similar to those specified in this test method. This test method has been found useful for specification purposes, but does not necessarily measure the lowest temperature at which the material is suitable for use.

1.1 This test method covers the determination of the temperature at which plastics and elastomers (as defined by Terminology D883) exhibit brittle failure under specified impact conditions. Two routine inspection and acceptance procedures are also provided.

Note 1: When testing rubbers for impact brittleness use Test Method D2137. When testing plastic sheeting for impact brittleness, use Test Method D1790.

1.2 The values stated in SI units are to be regarded as the standard.

1.3 Due to the potential safety and environmental hazards associated with mercury-filled thermometers, the use of alternative temperature measuring devices (such as thermocouples and RTDs) is encouraged.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Note 2: This test method and ISO 974 address the same subject matter, but differ in technical content.