1.1 本分类涵盖了通过对无应力试样进行简单浸泡试验来测定和分类聚氯乙烯均聚物和共聚物化合物以及氯化聚氯乙烯（CPVC）化合物在化学品中的电阻的方法。 1.2 该分类适用于规范中定义的任何PVC或CPVC化合物 D1784 , D4216 , D4396 或 D4551 . 1.3 以国际单位制表示的数值应视为标准值。 1.4 本标准的文本引用了提供解释材料的注释和脚注。 这些注释和脚注（不包括表和图中的注释和脚注）不应视为本标准的要求。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 注1: 没有涵盖该分类主题的ISO标准。 1. 6. 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。 ====意义和用途====== 4.1 对于任何PVC/CPVC材料化合物规范，请参考该耐化学性分类，其中要求对特定化学品具有一定程度的耐化学性，以获得满意的产品性能。 4.2 附录中列出的化学品并不意味着PVC/CPVC的兼容性或对化学品的耐受性。列出的一些化学品可能对特定化合物有害，导致物理性质发生根本变化。在规范中，对这些化学品的耐受性不是实际要求。 4.3 对于化学品混合物的耐受性，建议测试混合物，而不是接受单个化学品的耐受性，因为组合化学品的溶解能力可能会增强。 4.4 本分类中测试的样本是无应力的。当使用条件包括应力或其他因素，或两者兼有时，在实际使用条件下测试PVC/CPVC化合物的耐化学性。

1.1 This classification covers the method for determining and classifying the resistance of poly(vinyl chloride) (PVC) homopolymer and copolymer compounds, and chlorinated poly(vinyl chloride) (CPVC) compounds in chemicals by simple immersion testing of unstressed specimens. 1.2 This classification is applicable to any PVC or CPVC compound as defined in Specifications D1784 , D4216 , D4396 , or D4551 . 1.3 The values stated in SI units are to be regarded as standard. 1.4 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard. 1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Note 1: There are no ISO standards covering the subject matter of this classification. 1.6 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. ====== Significance And Use ====== 4.1 Reference this chemical resistance classification for any PVC/CPVC material compound specification wherein a level of resistance to specific chemicals is required for satisfactory product performance. 4.2 Listing of a chemical in the annex does not imply PVC/CPVC compatibility or resistance to the chemical. Some of the chemicals listed could be deleterious to a specific compound, causing radical changes in the physical properties. Resistance to these chemicals is not intended to be a practical requirement in a specification. 4.3 For resistance to mixtures of chemicals, it is suggested that the blend be tested rather than accepting the resistance of the individual chemicals because of a possible solvency enhancement of the combined chemicals. 4.4 The specimens tested in this classification are unstressed. When service conditions include stress or other factors, or both, test chemical resistance of the PVC/CPVC compound under actual service conditions.