This International Standard specifies the basic test procedures for the determination of the physical properties of self-skinned, high-density (typically having an overall density in excess of 100 kg/m3) rigid cellular plastic materials. This standard also specifies the primary methods to be used for comparison of materials similar to selfskinned, high-density materials as defined in clause 3, based upon IS0 test methods and using a standard test specimen thickness. It likewise permits the use of the same test methods, when found to be suitable, for the assessment of the properties of products of different thickness, when agreed upon by the supplier and the purchaser.