1.1 本规范涵盖硝化级二甲苯。 1.2 以下内容适用于本标准中规定的所有限值:为了确定是否符合本标准，观测值或计算值应按照惯例四舍五入法，在表示质量标准限值时使用的最后一位右手数字中四舍五入至“最接近的单位” E29 . 1.3 以SI单位表示的值将被视为标准值。括号中给出的值仅供参考。 1.4 有关本规范中使用的所有材料，请参考OSHA法规、供应商的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》中确立的国际公认的标准化原则制定的。

1.1 This specification covers nitration grade xylene. 1.2 The following applies to all specified limits in this standard: for purposes of determining conformance with this standard, an observed value or a calculated value shall be round off “to the nearest unit” in the last right-hand digit used in expressing the specification limit, in accordance with the round-off method of Practice E29 . 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.4 Consult 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.