1.1本试验方法包括在吸入毒理学研究的吸入暴露室内测定空气中金属和金属氧化物纳米颗粒的表面积。表面积可通过使用氮、氪和氩等吸附质的气体吸附法测量（Brunauer等人，1938；Anderson，1975；Gregg和Sing，1982） (1, 2, 3) 2. 或者通过基于离子附着和迁移率的方法（Ku和Maynard，2005） (4) . 本试验方法专门用于通过气体吸附和氪气体吸附测量表面积。该测试方法允许使用任何现代商用氪吸附仪器，但严格定义了金属和金属氧化物纳米颗粒的样品采集、放气和分析程序。 由于含颗粒样品的总表面积较低，并且需要准确测量用于样品采集的过滤器的背景表面积，因此需要使用氪。仪器根据多点Brunauer、Emmett和Teller（BET）方程报告表面积值（Brunauer等人，1938；Anderson，1975；Gregg和Sing，1982） (1, 2, 3) 用于计算过滤器上收集的空气中纳米颗粒的表面积。 1.2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。以国际单位制表示所有数值，除非特定仪器软件使用替代单位报告表面积。 1.3 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和健康实践，并确定监管限制的适用性。 ====意义和用途====== 5.1需要一种表征纳米颗粒特性的分层策略，以便就吸入毒理学实验期间观察到的剂量-反应关系得出有意义的结论。该分层策略包括纳米颗粒的表征 生产时 （即，按供应商出售的散装材料计量）和 按管理 （即，在交付给受试者时测量）（Oberdorster等人，2005年） (6) . 5.2试验方法B922和C1274以及ISO标准9277和18757用于测定 生产时 大块金属和金属氧化物粉末的表面积。在吸入暴露室中输送金属和金属氧化物纳米颗粒的过程中，材料特性可能会发生变化，因此具有不同于材料的特性 生产时 . 本试验方法描述了 按管理 用于吸入毒理学研究的吸入暴露室内空气中金属和金属氧化物纳米颗粒的表面积。

1.1 This test method covers determination of surface area of airborne metal and metal oxide nanoparticles in inhalation exposure chambers for inhalation toxicology studies. Surface area may be measured by gas adsorption methods using adsorbates such as nitrogen, krypton, and argon (Brunauer et al., 1938; Anderson, 1975; Gregg and Sing, 1982) (1, 2, 3) 2 or by ion attachment and mobility-based methods (Ku and Maynard, 2005) (4) . This test method is specific to the measurement of surface area by gas adsorption by krypton gas adsorption. The test method permits the use of any modern commercial krypton adsorption instruments but strictly defines the sample collection, outgassing, and analysis procedures for metal and metal oxide nanoparticles. Use of krypton is required due to the low overall surface area of particle-laden samples and the need to accurately measure the background surface area of the filter used for sample collection. Instrument-reported values of surface area based on the multipoint Brunauer, Emmett and Teller (BET) equation (Brunauer et al., 1938; Anderson, 1975; Gregg and Sing, 1982) (1, 2, 3) are used to calculate surface area of airborne nanoparticles collected on a filter. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. State all numerical values in terms of SI units unless specific instrumentation software reports surface area using alternate units. 1.3 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 and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== 5.1 A tiered strategy for characterization of nanoparticle properties is necessary to draw meaningful conclusions concerning dose-response relationships observed during inhalation toxicology experiments. This tiered strategy includes characterization of nanoparticles as produced (that is, measured as the bulk material sold by the supplier) and as administered (that is, measured at the point of delivery to a test subject) (Oberdorster et al., 2005) (6) . 5.2 Test Methods B922 and C1274 and ISO Standards 9277 and 18757 exist for determination of the as produced surface area of bulk metal and metal oxide powders. During the delivery of metal and metal oxide nanoparticles in inhalation exposure chambers, the material properties may undergo change and therefore have properties that differ from the material as produced . This test method describes the determination of the as administered surface area of airborne metal and metal oxide nanoparticles in inhalation exposure chambers for inhalation toxicology studies.