1.1 本指南介绍了室内空气中全氟烷基物质和多氟烷基物质（PFAS）浓度的测定方法。 1.2 本指南侧重于适用于室内空气（包括车辆和室内工作场所）和其他相关风量（如室内空气、袋子或两者）的PFAS测量技术。所述技术是针对室内空气开发的；它们可能适用于也可能不适用于其他类型的空气样本。 1.3 本指南介绍了可用于测量室内空气中气相或颗粒相或两者的PFAS浓度的可用技术和方法。 1.4 本指南介绍了每种方法及其优点和局限性。 1.5 本指南不试图区分方法的有效性，也不确定方法的等效性。 1.6 本指南中介绍的基于吸附剂的采样策略适用于分子量大于200的PFAS化合物 g 摩尔 1. ( 1. , 2. , 3. ) . 2. 小于200的化合物 g 摩尔 1. ，例如CF 4. C 2. F 6. ，或PFAS降解产物可能需要本指南中描述的实时分析方法或此处未介绍的其他方法。 1.7 单位-- 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.8 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 1.9 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。 ====意义和用途====== 5.1 一些PFAS与人类健康的不良影响有关 ( 4. , 5. , 6. ) 因此，量化室内空气中全氟辛烷磺酸的浓度对于准确和有意义的暴露分析和风险评估非常重要。 5.2 在空气中发现的PFAS可能具有广泛的化学特性，这将影响采样实践的选择。例如，估计的蒸汽压值可以变化十个数量级，而估计的亨利定律常数可以变化五个数量级( 表1 ). 这意味着适用于一种全氟辛烷磺酸化合物的取样和分析方法可能不适用于其他全氟辛烷酸化合物。因此，在采样和选择室内空气中全氟辛烷磺酸测量的分析方法之前，至关重要的是要确定所选的全氟辛烷酸采样方法适用于目标化合物、采样位置和环境条件。 5.3 室内空气中PFAS的测量是一个活跃且不断发展的研究课题。对PFAS特性、采样和分析方法和技术的理解正在不断发展。这包括许多PFAS的物理化学性质的测定，这些PFAS甚至可能没有经过实验测量，或者具有广泛的实验确定的性质（即 表1 ). 本指南介绍了出版时正在使用的方法。 5.4 室内空气中的PFAS可能来自广泛的来源，包括消费品、建筑材料、食品包装、室外空气和其他杂项来源。PFAS也通常在室内灰尘中进行定量。有几种方法可以量化固体和液体介质中的这些化学物质，包括但不限于指南 E3302 ，试验方法 D7968 ，试验方法 D7979 ，试验方法 D8421 ，试验方法 D8535 ，US EPA 533和US EPA 537.1。美国环保局OTM-45量化了固定来源的混合气相和颗粒相中的一些PFAS，如焚烧炉烟囱取样。 5.5 本指南适用于室内空气中PFAS的采样（通常为15 °C至30 °C，20 % 至80 % 相对湿度（RH））。虽然土壤蒸汽侵入等来源会影响室内空气，但此处描述的方法不一定在其他气体环境中应用或验证，如土壤孔隙蒸汽、烟囱样本或室外环境空气条件下（<10 °C，>30 °C，<20 % RH，>80 % RH）。这里提供的方法和信息可以应用于或兼容于其他PFAS或PFAS类化合物的测定，如氟里昂和其他环境中的温室气体，包括其他收集和获取方案，如罐法。然而，本指南的范围仅限于观察报告的室内空气中的PFAS。

1.1 This guide describes methods for determining Per- and Polyfluoroalkyl Substances (PFAS) concentrations in indoor air. 1.2 This guide is focused on PFAS measurement technologies applicable to indoor air (including in vehicles and indoor workplaces) and other relevant air volumes such as, air in chambers, bags, or both. The described technologies were developed for indoor air; they may or may not be applicable to other types of air samples. 1.3 This guide describes available technologies and methods that can be used to measure indoor air PFAS concentrations in the gaseous or particulate phases, or both, in indoor air. 1.4 This guide describes each method and its advantages and limitations. 1.5 This guide does not attempt to differentiate between the effectiveness of the methods nor determine equivalence of the methods. 1.6 The sorbent-based sampling strategies addressed in this guide are for PFAS compounds with a molecular mass greater than 200 g mol -1 ( 1 , 2 , 3 ) . 2 Compounds less than 200 g mol -1 , such as CF 4 , C 2 F 6 , or PFAS degradation products may require real-time analytical methods described in this guide or other methods that are not presented here. 1.7 Units— The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.8 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. 1.9 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 ====== 5.1 Some PFAS have been implicated in adverse human health impacts ( 4 , 5 , 6 ) . Therefore, quantifying PFAS concentrations in indoor air is important for accurate and meaningful exposure analysis and risk assessments. 5.2 PFAS found in air can have a wide range of chemical characteristics that will impact sampling practice selection. For example, estimated vapor pressure values can vary by ten orders of magnitude, while estimated Henry’s Law constants can vary by five orders of magnitude ( Table 1 ). This means that sampling and analytical methods that are appropriate for one PFAS compound may not be appropriate for other PFAS compounds. Hence, prior to sampling and selecting analytic methods for PFAS measurement in indoor air, it is critical to establish that the chosen PFAS sampling method(s) is appropriate for the target compound(s), the sampling location, and the environmental conditions. 5.3 The measurement of PFAS in indoor air is an active and growing research topic. Understanding of PFAS properties, sampling and analytic approaches and techniques is constantly evolving. This includes the determination of physical-chemical properties of many PFAS, which may not even have been measured experimentally or which have a wide range of experimentally determined properties (that is, 8:2 FTOH in Table 1 ). This guide describes methods that are in use at the time of publication. 5.4 PFAS in indoor air may come from a wide range of sources, including consumer products, building materials, food packaging, outdoor air, and other miscellaneous sources. PFAS is also commonly quantified in indoor dust. There are several methods that quantify these chemicals in solid and liquid media including, but not limited to Guide E3302 , Test Method D7968 , Test Method D7979 , Test Method D8421 , Test Method D8535 , US EPA 533, and US EPA 537.1. US EPA OTM-45 quantifies some PFAS in the combined gas and particle phases of stationary sources, such as incinerator stack sampling. 5.5 This guide is applicable to sampling PFAS in indoor air (typically 15 °C to 30 °C, 20 % to 80 % relative humidity (RH)). While sources like soil vapor intrusion impact indoor air, the methods described here have not necessarily been applied or verified in other gaseous environments, such as soil pore vapor, stack samples, or under ambient outdoor air conditions (<10 °C, >30 °C, <20 % RH, >80 % RH). The methods and information presented here may apply or be compatible with determination of other PFAS or PFAS-like compounds, such as freons and greenhouse gases in other environments, including other collection and acquisition schemes, such as canister methods. However, the scope of this guide is limited to observationally reported PFAS in indoor air.