1.1 本规范涵盖的等级为 奥 -二甲苯鉴定为 正交的 -二甲苯980。 1.2 以下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，应根据实践中的四舍五入方法，将观测值或计算值四舍五舍五入至表示规范限值时使用的右最后一位数字中最接近的单位 第29页 。 1.3 以国际单位制表示的数值应视为标准。本标准中不包括其他计量单位。 1.4 查阅当前OSHA法规和供应商的安全数据表，以及本规范中使用的所有材料的当地法规。 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》中确立的国际公认的标准化原则制定的。

1.1 This specification covers a grade of o -xylene identified as ortho -Xylene 980. 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 and 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.