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 either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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 and health practices and determine the applicability of regulatory limitations prior to use.