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. Note 1 - This test method is equivalent to ISO 845.