1.1 该分类体系涵盖间规聚苯乙烯材料，包括均聚物、共聚物、共混物和冲击改性材料，适用于成型和挤出。回收产品将在单独的标准中解决。 1.2 本分类系统和随后的线形标注（规范）旨在提供一种方法，指出用于制造最终用途项目或零件的塑料材料。它不用于材料的选择。只有在仔细考虑零件所需的设计和性能、其将暴露的环境、将采用的制造工艺、除本分类系统涵盖的材料之外的材料的固有特性和经济性后，才可以由在塑料领域具有专业知识的人员进行材料选择。 1.3 该分类系统中包含的属性是识别所涵盖成分所需的属性。识别对专业应用程序重要的特定特征所需的其他要求将使用第节中给出的后缀 5. . 注1: 没有已知的ISO等效于本标准。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

1.1 This classification system covers syndiotactic polystyrene materials including homopolymer, copolymers, blends, and impact modified, suitable for molding and extrusion. Recycled product will be addressed in a separate standard. 1.2 This classification system and subsequent line callout (specification) are intended to provide a means of calling out plastic materials used in fabrication of end use items or parts. It is not intended for the selection of matierials. Material selection can be made by those having expertise in the plastics field only after careful consideration of the design and the performance required of the part, the environment to which it will be exposed, the fabrication process to be employed, the inherent properties of the material other than those covered by this classification system, and the economics. 1.3 The properties included in this classification system are those required to identify the compositions covered. Other requirements necessary to identify particular characteristics important to specialized applications are to be called out using the suffixes given in Section 5 . Note 1: There is no known ISO equivalent to this standard. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.