1.1 This test method provides a means for estimating the resistance of polypropylene, in molded form, to accelerated aging by heat in the presence of air using a forced draft oven.

1.2 The stability determined by this test method is not directly related to the suitability of the material for use when different environmental conditions prevail and shall not be used to predict performance.

Note 1--The specified thermal levels in this test method are considered sufficiently severe to cause failure of commercial grades of heat-stable polypropylene within a reasonable period of time. If desired, lower temperatures can be applied to estimate the performance of polypropylene with lower heat stabilities.

1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

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 4577-1983 are technically similar but different in preparation of test specimens, thickness of test specimen, measurement of the number of air flow changes in the ovens, and the number of air changes per hour required.