This specification covers high-density cellular rubber adhered to carpet, rugs, or various substrates for use as separate underlay. This standard may also be used as a specification for separately blown sponge used as carpet underlay. 1.2 This specification provides material and dimensional requirements and test methods for specific properties of compression set, compression resistance or compression force deflection, delamination strength, and accelerated aging. NOTE 1—This specification does not include requirements for burning characteristics. It shall be noted that Flammable Fabrics Act Regulations FF1-70, Standard for the Surface Flammability of Carpets and Rugs, and FF2-70, Standard for the Surface Flammability of Small Carpets and Rugs, may be applicable for carpets and rugs with integral backing of rubber cellular cushion. 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 2—There is no similar or equivalent ISO standard.