4.1 If the material to be tested includes forming skins, the apparent overall density, or the apparent core density, or both, shall be determined. If the material does not have forming skins, the term overall density is not applicable.

4.2 This test method is also applicable to spray foam materials.

4.3 Before proceeding with this test method, reference shall be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or combination thereof, covered in the relevant ASTM materials specification shall take precedence over those mentioned in this test method. If there are no relevant ASTM material specifications, then the default conditions in this method apply.

4.4 When density or apparent density is used in reference to a cellular plastic, without further qualification, it shall be interpreted as follows:

1.1 This test method covers the density of a cellular plastic. Density can be evaluated as the apparent overall density (includes forming skins) or by apparent core density (forming skins removed).

1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.

1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.