1.1 This specification covers the identification of polyethylene plastic pipe and fittings materials in accordance with a cell classification system. It is not the function of this specification to provide specific engineering data for design purposes, to specify manufacturing tolerances, or to determine suitability for use for a specific application. 1.2 Polyethylene plastic materials, being thermoplastic, are reprocessable and recyclable (Note 2). This specification allows for the use of those polyethylene materials, provided that all specific requirements of this specification are met. NOTE 1—The notes in this specification are for information only and shall not be considered part of this specification. NOTE 2—See Guide D5033 for information and definitions related to recycled plastics. 1.3 The values stated in SI units are to be regarded as standard. 1.4 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 3—There is no known ISO equivalent to this standard. 1.5 For information regarding molding and extrusion materials see Specification D4976. For information regarding wire and cable materials see Specification D1248