1.1 本规范涵盖高纯度 p -二甲苯。 1.2 以下内容适用于本规范中的所有规定限值:为了确定是否符合本规范，应根据修约实践方法，将用于表示规范限值的最后一个右手数字中的观察值或计算值修约为“最接近的单位” E29年 . 1.3 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.4 有关本规范中使用的所有材料，请参阅现行OSHA法规、供应商安全数据表和当地法规。 1.5 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 specification covers high purity p -Xylene. 1.2 The following applies to all specified limits in this specification: for purposes of determining conformance with this specification, an observed value or a calculated value shall be rounded off “to the nearest unit” in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E29 . 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 Consult current OSHA regulations, supplier’s Safety Data Sheets, and local regulations for all materials used in this specification. 1.5 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.