1.1 全氟烷基和多氟烷基物质( PFAS )是由7000多种人造化合物组成的一组，这些化合物由与氟原子结合的碳聚合物链组成，通常在顶部带有极性官能团。本指南认识到 PFAS 可分为聚合物或非聚合物，总计超过4700种化学文摘社（CAS）注册物质。与 PFAS 主要集中在全氟烷基酸（PFAA）上，这是全氟烷基和多氟烷基物质的一个亚类，在生物群中表现出极端的持久性和链长依赖性生物累积性和不良影响。 1.2 监管框架 PFAS 在国内和国际上继续发展。 美国环境保护局( EPA )正在进行一系列广泛的 PFAS 监管行动（EPA，2021）。而《综合环境应对、赔偿和责任法》( 环扎 )当前无法识别 PFAS 像 危险物质 ，该法令确实要求采取行动保护公众健康和环境免受污染物和污染物释放到环境中。其他联邦监管计划，如《安全饮用水法》，正被用于解决受 释放 属于 PFAS .《清洁水法》的国家污染物排放消除系统( NPDES )许可计划是联邦和州监管机构用来监管资金流入的工具 PFAS -受影响的 废水 在两家公有的处理厂( POTW )和联邦所有 废水 处理厂和 PFAS 在允许的污水中。 EPA 继续将额外的全氟烷基和多氟烷基物质添加到联邦有毒物质释放清单下可报告的物质清单中( TRI )报告程序。解决全氟烷基和多氟烷基物质的国际努力包括澳大利亚的PFAS国家环境管理计划第2版（2020年）、加拿大的《禁止某些有毒物质条例》（2022年）、《关于持久性有机污染物的斯德哥尔摩公约》和欧盟的《水框架指令》 ( 1. ) 。 2. 1.3 危险废物 治疗 存储 和 处置 设施( TSDF )目前根据《资源保护和回收法》运作( RCRA )通过B部分许可证可以被命令进行调查 释放 属于 PFAS 在 RCRA 纠正措施指令。 EPA 在20世纪90年代做出了一项政策决定，推迟了许多潜在的 环扎 对 RCRA 《纠正措施计划》（EPA，1999年）。被允许 TSDF 在炼油厂可能受到 RCRA 纠正措施，与其他监管计划相反，旨在解决 释放 属于 PFAS 关联的过去和现在的使用 水成膜泡沫灭火剂 ( AFFF )。 1.4 许多州和部落正在利用其现有的监管计划来指导与 释放 属于 PFAS 土壤、地下水和地表水。这些行动范围从健康咨询和指导方针到可执行的监管标准。监管考虑因素包括 PFAS 人类健康和生态受体面临的风险受到广泛的联邦、州和部落监管计划以及条约权利的保护。 1.5 本指南有助于 用户 在识别可能是 PFAS 释放 或可能受到以下不利影响 释放 属于 PFAS .本指南的目的是协助环境风险管理者进行资源分配决策。 1.6 本指南不构成《美国联邦法规》第40卷第312部分中定义的“所有适当的询问”，也不旨在提供 使用者 任何土地所有者责任保护 环扎 §101（35）（A）（i）， 环扎 §101（40）（B）（iii），或《综合环境责任法》§107（q）（1）（A）（viii）。 1.7 本指南介绍了现场筛选和初始现场表征过程中广泛接受的考虑因素和最佳实践，并具体考虑了 释放 属于 PFAS 进入环境。本指南补充但不取代现有的技术指南和监管要求。 1.8 本指南不涉及也不适用于受《安全饮用水法》和州-私人试井法要求监管的公共或私人生活供水系统的采样和分析。 负责实施《安全饮用水法》的监管机构可能已经制定了公共、社区和私营供水系统的采样和报告要求。 1.9 截至出版之日，所有对特定联邦或州计划的引用都是最新的。这个 使用者 提醒不要仅依赖本指南，而是就这一复杂且快速发展的问题直接咨询适当的项目和法律顾问。 1.10 本指南旨在补充而非取代现有的监管要求或指南。ASTM国际（ASTM）指南不是规定；它们是基于共识的标准，可以根据需要遵循。 1.11 单位-- 以国际单位制表示的数值应视为标准。其他单位，如十亿分之一（ppb）和万亿分之一（ppt）的分数单位，也包括在本指南中。 1.12 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。 1.13 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====== 4.1 PFAS 广泛应用于世界各地的商业和工业应用中（请参阅 图1 )。 PFAS 由于其有文献记载的持久性及其对人类健康和环境的影响而备受关注。虽然没有关于许多个人的全面信息来源 PFAS 物质及其在不同应用中的功能，从业者可以获得一系列资源。本指南提供的信息有助于从业者在初步筛选和现场表征过程中应对这些挑战。 图1 可能是PFAS使用和释放来源的活动/行业 资料来源:AEI咨询公司 4.2 这个 使用者 应该注意 PFAS 联邦和州一级的监管管理框架正在迅速发展。因此，咨询具有联邦、州和地方知识的法律和技术代表 PFAS 在使用本指南之前，建议遵守相关规定。环境审计政策或特权可能适用于本指南中描述的一些步骤（见EPA，2000）。 4.3 多步骤风险管理框架: 4.3.1 本指南中描述的行动旨在提供一个多步骤风险管理框架，以合理的确定性确认 PFAS 可能在联邦所有、公有或私有财产中使用。本标准提供了如何将有限资源集中用于使用- 步骤过程，如所示 图2 ，以确定可能受到现场或场外使用影响的财产，以及 释放 属于 PFAS 部分 4.5 描述了 PFAS 部分 4.6 描述了政府和联邦设施的活动 PFAS 预期会使用。部分 4.7 大致概述了使用 PFAS 已记录在案（Glüge，2020 ( 2. ) ，盖恩斯，2022 ( 3. ) )。 图2 初步现场筛选和表征流程图 4.4 PFA历史和用途: 4.4.1 在20世纪40年代，工业过程商业化生产 PFAS 最早开发。从那时起 PFAS 已被用于制造世界各地的许多工业和消费品。自20世纪50年代以来， PFAS 已广泛用于纸张、织物、炊具和地毯的表面处理应用，使这些产品和材料能够抵御油、水和污渍。在20世纪60年代，美国海军使用 PFAS 发展 水性成膜泡沫 该技术已获得美国海军的专利。自20世纪60年代以来，美国食品药品监督管理局（FDA）已经批准了几大类 PFAS 由于其不粘、耐油脂、耐油和防水性能，可用于食品接触物质。在过去的50年里， PFAS 在全球范围内，食品和消费品制造、包装以及工业运营和应用领域的使用已经扩大。 限制或禁止使用 PFAS 在食品和消费品方面，已经在国家和地方层面颁布了法律。 4.4.2 释放 属于 PFAS 在制造过程中，可能已经发生并可能继续发生，随后重新沉积 PFAS 土地上的材料 PFAS 可以进入地表水和地下水。其他潜在的 PFAS 排放物是干洗和商业洗衣操作，其中衣服涂有 PFAS -包含材料的物品被清洗或洗涤。这些来源的排放物可能包括棉绒等颗粒物。此外， PFAS 可能未经治疗就出院 废水 处理厂或 垃圾填埋场 ，并最终通过非设计用于缓解的处理系统释放到环境中 PFAS .工业排放 PFAS 多年来不受监管；然而，美国正在州、联邦以及国际层面进行变革。 4.4.3 广泛而言 PFAS -含有产品和废物 释放 PFAS 进入 垃圾填埋场 和 垃圾填埋 渗滤液，并进入市政 废水 ，在那里它可能在可能被陆地应用的生物固体中未被发现地积累。 PFAS 可随后用于土壤改良剂，用于种植动物饲料和粮食作物以及供人类食用的产品。这个 使用者 应注意影响 PFAS ，包括空气排放， 废水 排放、生物固体、地下水、地表水和受影响土壤正在迅速演变，可能包括额外的报告要求。 ( 4. ) 4.5 PFAs的使用和发生: 4.5.1 PFAS 含氟化学品已被广泛用于联邦和商业活动，如 图1 .使用 PFAS 作为 AFFF 用于军事设施、炼油厂、石化制造设施、罐区和机场的消防是众所周知的。 PFAS 用作织物和纸制品的涂层，以防水和防油脂（参见ITRC的PFAS技术指南）。 PFAS 也已经是用于电镀操作的蒸汽控制雾的组成部分。 其他工业用途 PFAS 也在本节中进行了描述。 4.6 PFA的政府和军事设施使用: 4.6.1 PFAS 已在政府/军事设施的各种应用中使用，包括作为 AFFF ，通常用于消防训练区和设备测试区，目前仍在坠机现场和机库的一些灭火系统中使用。此外 PFAS 一直是与联邦设施和政府所有、承包商运营的电镀作业相关的抑雾化合物的组成部分( GOCO )研发工厂。这个 废水 处理厂( WWTP )在联邦设施 释放 PFAS 作为排放物，并可能排放 PFAS 进入作为流出物的接收水中。由 WWTP 可能包含 PFAS 如果 PFAS 存在于进水中。 4.6.2 当前和历史 AFFF 存储 联邦政府拥有的设施的转移区可能会引起关注 释放 环境。关于不受控制的泄漏和重复使用 AFFF 在消防训练和灭火期间 PFAS 地表水和地下水。消防实践中的液体排放到雨水和下水道系统以及蓄水池是潜在的来源区域。此外，其他 危险物质 在安装时应考虑潜在的源区域。 4.6.2.1 因此，识别重要 PFAS 联邦所有设施的来源是 存储 和使用 AFFF 。 PFAS 从…起 AFFF 用于消防和灭火系统被认为具有最大的潜力 释放 属于 PFAS 在政府/军事设施的大规模集中方面对环境的影响。 4.6.2.2 其他潜在的 PFAS 环境包括历史现场土地 处置 区域/ 垃圾填埋场 包含操作废物（例如来自电镀）， 废水 污泥和污水处理，或 PFAS 材料本身。 垃圾填埋 渗滤液可能携带 PFAS 地下水。 4.6.3 AFFF 消防演习和灭火中使用的是水性的（60-90%），通常含有烃基表面活性剂，如烷基硫酸钠，以及氟表面活性剂（如氟调聚物、全氟辛烷磺酸和/或全氟辛烷酸）。 AFFF 包含 PFAS 于20世纪60年代初至中期开发用于B级火灾，并于20世纪70年代初在政府设施中投入常规使用，至今仍在使用。 4.6.3.1 3M、杜邦、安苏尔和Chemguard等公司是主要的消防泡沫生产商，在生产 AFFF 典型的 AFFF 使用- 线性喷射器或其他比例装置，以产生3 % 至6 % 浓缩液的。如前所述， AFFF 主要用于B类燃料火灾，因为 PFAS 在里面 AFFF 形成了一层厚厚的泡沫毯。A类灭火泡沫用于扑灭木材和草地火灾，不含 PFAS 。 4.6.4 弹药的露天燃烧/露天引爆-- 公开焚烧和公开引爆弹药是一些军事设施和联邦设施的非常规活动。可能包含的弹药类型 PFAS 主要限于烟火（照明弹）。弹药的露天燃烧、露天引爆受 RCRA 许可程序（见40 CFR 264第X子部分）。 注1: 如果露天引爆活动是装置培训计划的一部分，则根据 RCRA 子部分X.弹药停用炉和回转窑的温度高达1500°F，这可能不足以摧毁 PFAS （环保署，2005年）。露天焚烧可能无法达到足以破坏的温度 PFAS .弹药的不完全燃烧以及热失效 释放 PFAS 空气中。与 OB/OD 弹药的顺风飞行，应在命运和运输模型中加以考虑。 OB/OD 可能会留下残留物 PFAS 以及土壤中的金属。 4.6.5 电镀， 特别是硬镀铬是一种工业活动 PFAS -可能已经使用了含有抑雾剂的。 PFAS 有时在铬电镀过程中用作铬酸浴中的表面活性剂。可能进行电镀的联邦设施包括国防部对飞机、重型设备和船舶进行检修和维护的设施。政府所有、承包商运营的研发工厂也是历史上进行电镀作业的场所。 4.6.6 填埋作业、废物处理区和污水处理厂-- 从历史上看， 垃圾填埋场 接收政府/军事设施产生的废物，包括作业区（机械车间、电镀作业等）的废物流。 )、住宅区和 废水 处理厂。这些废物流可能含有工业和/或消费品 PFAS 或含有当它们降解时， 释放 PFAS ，可能会从 垃圾填埋 此外，污水处理厂的废物生物固体和污泥可能含有 PFAS 。 4.7 PFA的商业和工业用途: 4.7.1 的用途 PFAS 商业应用多种多样，涉及众多的商业和工业部门（Gaines 2022） ( 3. ) 。本指南侧重于重要的潜在来源 释放 属于 PFAS 环境。一些行业的例子 PFAS 已用于生产和制造的产品包括: 4.7.1.1 化学工业，特别关注含氟聚合物聚合中的加工助剂， 4.7.1.2 纺织品、服装、皮革、地毯和纸张的表面保护， 4.7.1.3 电子工业（半导体和电线；分别为NAICS 334400和335929）（注:和太阳能电池板）， 4.7.1.4 消费者和个人护理产品， 4.7.1.5 食品加工和包装， 4.7.1.6 塑料和橡胶生产， 4.7.1.7 纸浆和造纸工业， 4.7.1.8 涂料、油漆和清漆， 4.7.1.9 炼油和石化工业， 4.7.1.10 弹药和爆炸物生产， 4.7.1.11 飞机和重型设备制造， 4.7.1.12 公共部门和私营部门机场，以及 4. 7.1.13 零部件电镀。 4.7.2 如第节所述 4.6.5 ，电镀，特别是硬铬电镀，是一种工业活动 PFAS -可能已经使用了含有抑雾剂的。 PFAS 有时在铬电镀过程中用作铬酸浴中的表面活性剂。 4.7.3 化学工业特别关注含氟聚合物聚合中的加工助剂。的重要用途 PFAS 在化学工业中，它们作为加工助剂用于氟聚合物的聚合、氯和氢氧化钠的生产以及其他化学品的生产，包括 溶剂 。 PFAS 由于排放和毒性，用作含氟聚合物聚合过程中的加工助剂受到特别关注（Lohmann，2020） ( 5. ) 。 4.7.4 纺织品、服装、皮革、地毯和纸张的表面保护-- 大量 PFAS ，特别是侧链氟化聚合物，已被用作纺织品、服装、皮革、地毯和纸张的表面保护剂。可能含有 PFAS 包括食品包装、披萨盒、微波爆米花。这些都是开放和分散的用途，许多消费者都会接触到 PFAS -含有产品。侧链氟化聚合物含有作为杂质的全氟烷基酸，它们可以作为 PFAS 许多的 PFAS 前体（如醇、酰胺）可以降解为全氟烷基酸（经合组织，2007；Buck，R.C.等人2011 ( 6. ) )。 注2: 全氟烷基酸的毒理学和生态毒性评估尚处于初级阶段。 4.7.5 电子工业-- PFAS 已经被用作电子设备中的部件（例如在平板显示器或液晶显示器中）。 PFAS 还被用于测试电子器件和设备，作为传热流体/冷却剂，在清洁溶液中，沉积润滑剂，以及蚀刻压电陶瓷过滤器。 PFAS 也用于半导体和布线的生产。 4.7.6 塑料和橡胶生产-- PFAS 已被用作模具 释放 发泡剂，发泡剂，泡沫调节剂，聚合物加工助剂，塑料蚀刻剂，抗- 用于橡胶的堵剂以及塑料和橡胶生产中的固化剂。含氟聚合物可以提高塑料和橡胶的加工效率和质量。使用 PFAS 在塑料和橡胶的生产中可以解释为什么 PFAS 在最终产品中发现，例如在人造草皮中。 4.7.7 涂料、油漆和清漆-- 大量的含氟聚合物已被用于涂料和涂料中，以赋予拒油和拒水性。含氟聚合物也被用作防粘和防腐涂层。 4.7.8 炼油厂和石化工业-- 如前所述， AFFF 包含 PFAS 已用于炼油厂、石化制造厂和散装 存储 以及配电终端。这些设施的灭火系统要经过周期测试。灭火含水量 AFFF 在工厂的 WWTP 或已出院。 4.7.9 弹药和爆炸物生产-- PFAS 在一小部分能量学中用作粘合剂和氧化剂，在一些军用弹药中用作衬套、o型环或其他部件（SERDP 2020） ( 7. ) .军火制造商历来都会发布 PFAS 通过公开焚烧弹药废料。 4.7.10 飞机和重型设备制造-- 在零件和设备的生产和制造中使用电镀的行业可能已经使用 PFAS -含有化学物质。 4.7.11 公共部门和私营部门机场-- AFFF 包含 PFAS 已被用于某些机场的灭火训练，包括散装燃料 存储 储罐。灭火培训使用 AFFF 定期在机场进行。灭火含水量 AFFF 在机场现场处理之前，可能会收集在滞留池中 WWTP ，排放到雨水输送系统，或流到场外 WWTP 。 4.7.12 洗车-- PFAS 是商业洗车中肥皂和蜡的成分（NAICS代码811192）。 集水坑 洗车场失去结构完整性的集水池可能是 释放 。

1.1 Per- and polyfluoroalkyl substances ( PFAS ) are a group of over 7,000 manmade compounds consisting of polymeric chains of carbon bonded to fluorine atoms, usually with a polar functional group at the head. This guide recognizes that PFAS can be categorized as polymeric or nonpolymeric, collectively amounting to more than 4,700 Chemical Abstracts Service (CAS)-registered substances. Environmental concerns pertaining to PFAS are centered primarily on the perfluoroalkyl acids (PFAA), a subclass of per-and polyfluoroalkyl substances, which display extreme persistence and chain-length dependent bioaccumulation and adverse effects in biota. 1.2 The regulatory framework for PFAS continues to evolve, both domestically and internationally. The United States Environmental Protection Agency ( EPA ) is proceeding with a wide-ranging set of PFAS regulatory actions (EPA, 2021). While the Comprehensive Environmental Response, Compensation, and Liability Act ( CERCLA ) does not currently recognize PFAS as hazardous substances , the statute does require actions to protect public health and the environment from contaminants and pollutants released to the environment. Other federal regulatory programs, such as the Safe Drinking Water Act are being used to address drinking water supplies adversely impacted by releases of PFAS . The Clean Water Act’s National Pollutant Discharge Elimination System ( NPDES ) permitting program is tool that both federal and state regulators are using to regulate the inflows of PFAS -impacted wastewaters at both publicly-owned treatment works ( POTW ) and federally-owned wastewater treatment plants and the concentration of PFAS in permitted effluent. EPA continues to add additional per-and polyfluoroalkyl substances to the list of substances reportable under the federal Toxic Release Inventory ( TRI ) reporting program. International efforts to address per-and polyfluoroalkyl substances include Australia’s PFAS National Environmental Management Plan, Version 2 (2020), Canada’s Prohibition of Certain Toxic Substances Regulations, (2022), the Stockholm Convention on Persistent Organic Pollutants, and the European Union’s Water Framework Directive ( 1 ) . 2 1.3 Hazardous waste treatment, storage , and disposal facilities ( TSDF ) currently operating under the Resource Conservation and Recovery Act ( RCRA ) via a Part B Permit may be ordered to investigate releases of PFAS under a RCRA Corrective Action order. EPA made a policy decision in the 1990s to defer many potential CERCLA enforcement actions to the RCRA Corrective Action Program (EPA, 1999). Permitted TSDFs at refineries may be subject to RCRA Corrective Action, as opposed to other regulatory programs, to address the releases of PFAS associated past and current use of aqueous film-forming foam ( AFFF ). 1.4 Numerous states and Tribes are using their existing regulatory programs to direct investigation, site remediation, and correction action related to releases of PFAS to soil, groundwater, and surface waters. These actions range from health advisories and guidelines to enforceable regulatory standards. Regulatory considerations include PFAS risks to both human health and ecological receptors that are protected under a broad array of federal, state, and tribal regulatory programs as well as by treaty rights. 1.5 This guide assists users in the identification of real property concerns that may be the source of PFAS releases or that may be adversely impacted by releases of PFAS . The goal of this guide is to assist managers of environmental risk in their resource allocation decision-making. 1.6 This guide does not constitute “All Appropriate Inquiries” as defined in 40 CFR Part 312 and is not intended to provide the user with any of the landowner liability protections codified in CERCLA §101(35)(A)(i), CERCLA §101(40)(B)(iii), or CERCLA §107(q)(1)(A)(viii). 1.7 This guide describes widely accepted considerations and best practices used in the site screening and initial site characterization process, with specific consideration of the potential for the release of PFAS into the environment. This guide complements but does not replace existing technical guidance and regulatory requirements. 1.8 This guide does not address and is not applicable to sampling and analysis of public or private domestic water supply systems subject to regulation under the Safe Drinking Water Act and state private well testing act requirements. Regulatory agencies responsible for implementing the Safe Drinking Water Act may have established sampling and reporting requirements for public, community, and privately operated water systems. 1.9 All references to specific federal or state programs are current as of the date of publication. The user is cautioned not to rely on this guide alone but to consult directly with the appropriate program and legal counsel regarding this complex and rapidly evolving concern. 1.10 This guide is intended to complement, not replace, existing regulatory requirements or guidance. ASTM International (ASTM) guides are not regulations; they are consensus-based standards that may be followed as needed. 1.11 Units— The values stated in SI units are to be regarded as the standard. Other units, such as fractional units of parts per billion (ppb) and parts per trillion (ppt), are also included in this guide. 1.12 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. 1.13 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 ====== 4.1 PFAS are widely used in commercial and industrial applications worldwide (see Fig. 1 ). PFAS are of concern due to their documented persistence and their studied impacts on human health and the environmental. While there is no comprehensive source of information on the many individual PFAS substances and their functions in different applications, a range of resources are available to the practitioner. This guide provides information to assist the practitioner in navigating these challenges during the initial screening and site characterization process. FIG. 1 Activity/Industry that may be Sources of PFAS Use and Release Source: AEI Consultants 4.2 The user should note that PFAS regulatory management framework at the federal and state level are evolving quickly. Therefore, consultation with legal and technical representatives with knowledge of federal, state, and local PFAS regulations is advised prior to use of this guide. Environmental audit policies or privileges may be applicable to some of the steps described in this guide (see EPA, 2000). 4.3 Multi-step Risk Management Framework: 4.3.1 The actions described in this guide are intended to provide a multi-step risk management framework to confirm, with reasonable certainty, that PFAS may have been used at a federally-owned, publicly-owned, or privately-owned property. This standard provides guidance on how to focus limited resources on using a multi-step process, illustrated in Fig. 2 , to identify property potentially impacted by on-site or off-site uses and releases of PFAS . Section 4.5 describes the use and occurrence of PFAS . Section 4.6 describes activities at government and federal installations where PFAS use is expected. Section 4.7 broadly outlines the industry sectors where the use of PFAS has been documented (Glüge, 2020 ( 2 ) , Gaines, 2022 ( 3 ) ). FIG. 2 Initial Site Screening and Characterization Flow Diagram 4.4 PFAs History and Use: 4.4.1 In the 1940s, industrial processes to commercially produce PFAS were first developed. Since then, PFAS have been used to make many industrial and consumer products worldwide. Since the 1950s, PFAS have been widely used in surface treatment applications for paper, fabric, cookware and carpeting which allows these products and materials to repel oil, water, and stains. In the 1960s, the United States Navy used PFAS to develop Aqueous Film Forming Foam products for firefighting applications and the technology was patented by the U.S. Navy. Since the 1960s, the U.S. Food and Drug Administration (FDA) has authorized several broad classes of PFAS for use in food contact substances due to their non-stick and grease, oil, and water-resistant properties. Over the past 50 years, PFAS use has expanded in food and consumer products manufacturing and packaging and industrial operations and applications worldwide. Restrictions or prohibitions on the use of PFAS in food and consumer products have been enacted at the State and local level. 4.4.2 Release of PFAS during manufacture into the atmosphere may have occurred, and may be continuing to occur, followed by subsequent redeposition of PFAS materials on land where PFAS can enter surface water and groundwater. Other potential sources of PFAS emissions are dry cleaning and commercial laundry operations where clothing coated with PFAS -containing materials is cleaned or laundered. Emissions from these sources may include particulate matter such as lint. Additionally, PFAS may be or have been discharged without treatment to wastewater treatment plants or landfills , and eventually be released into the environment by treatment systems that are not designed to mitigate PFAS . Industrial discharges of PFAS were unregulated for many years; however, change is underway in the U.S. at both the state and federal level as well as internationally. 4.4.3 Broadly, consumer and industrial uses of PFAS -containing products and waste may release PFAS into landfills and landfill leachate, and into municipal wastewater , where it may accumulate undetected in biosolids which may be land applied. PFAS may be subsequently used in soil amendments used to grow animal feed and food crops and produce for human consumption. The user should be aware that federal, tribal, state, and municipal regulations affecting the management of PFAS , including air emissions, wastewater discharges, biosolids, groundwater, surface water, and impacted soil are rapidly evolving and may include additional reporting requirements. ( 4 ) 4.5 PFAs Use and Occurence: 4.5.1 PFAS containing chemicals have been used in a broad spectrum of federal and commercial activities, as illustrated in Fig. 1 . The use of PFAS as a component of AFFF for firefighting at military installations, refineries, petrochemical manufacturing facilities, tank farms, and airports is well known. PFAS are used as coatings for fabric and paper products to repel water and grease (see ITRC’s PFAS Technical Guide). PFAS have also been components of vapor control mists for electroplating operations. Other industrial uses of PFAS are described in this section as well. 4.6 Government and Military Installations Use of PFAs: 4.6.1 PFAS have been used in a variety of applications at government/military facilities, including as a component in AFFF , which was routinely used at fire-fighting training areas and equipment test areas and is still used at crash sites and some fire suppression systems in hangars. In addition, PFAS has been a component of mist-suppression compounds associated with electroplating operations at federal facilities and government-owned, contractor-operated ( GOCO ) research and development plants. The wastewater treatment plants ( WWTP ) at federal installations may release PFAS as emissions and may discharge PFAS into receiving waters as effluent. The biosolids produced by the WWTP may contain PFAS if PFAS were present in the influent. 4.6.2 Current and historical AFFF storage and transfer areas at federally-owned facilities are of potential concern for release to the environment. Historical reports of uncontrolled spills and the repeated use of AFFF during fire training and firefighting have been correlated with higher concentrations of PFAS in surface water and groundwater. Discharges of liquids from fire-fighting practices into stormwater and sewer systems and holding ponds are potential source areas. In addition, treated effluents from remediation of other hazardous substances at the installation should be considered potential source areas. 4.6.2.1 Accordingly, key elements for identifying significant PFAS sources at federally-owned facilities are the storage and use of AFFF . PFAS from AFFF used in firefighting and fire suppression systems are considered to have the greatest potential for release of PFAS to the environment in terms of mass concentration at government/military installations. 4.6.2.2 Other potential sources of PFAS to the environment include historical on-site land disposal areas/ landfills containing operations wastes (for example, from electroplating), wastewater treatment sludges and effluents, or PFAS materials themselves. Landfill leachate could carry PFAS to groundwater. 4.6.3 AFFF used in Fire-Fighting Exercises and Fire Suppression are water-based (60-90%) and frequently contain hydrocarbon-based surfactants, such as sodium alkyl sulfate, and fluorosurfactants, such as fluorotelomers, PFOA, and/or PFOS. AFFF containing PFAS were developed in the early to mid-1960s for use on Class B fires and were placed into routine use at government installations by the early1970s and are still in use today. 4.6.3.1 Companies including 3M, DuPont, Ansul, and Chemguard were the primary fire-fighting foam producers that used fluoro-chemical surfactants in the production of AFFF . Typically, AFFF concentrate was proportionally mixed into water lines using in-line eductors or other proportioning devices to create the necessary foam solution ranging from 3 % to 6 % of the concentrate. As noted, AFFF was primarily used with Class B fuel fires because the chemical properties of PFAS in AFFF created a thick foam blanket. Class A fire-fighting foams were used to extinguish wood and grass fires and do not contain PFAS . 4.6.4 Open Burning / Open Detonation of Munitions— Open burning and open detonation of munitions are non-routine activities at some military installations and federal facilities. The types of munitions that may contain PFAS are primarily limited to pyrotechnics (flares). The open- burning, open-detonation of munitions is subject to Subpart X of the RCRA Permitting Process (see 40 CFR 264, Subpart X). Note 1: If the open detonation activities are conducted are part of the installation’s training program, they may not be subject to permitting under RCRA Subpart X. Temperatures in munitions deactivation furnaces and rotary kilns reach up to 1500°F, which may not be adequate to destroy PFAS (EPA, 2005). Open burning may not achieve temperatures high enough to destroy PFAS . The incomplete combustion of munitions as well as thermal deactivation releases PFAS into the air. Emissions associated with OB/OD of munitions travel downwind and should be considered in the fate and transport model. OB/OD may leave residual PFAS and metals in soil. 4.6.5 Electroplating, specifically hard chromium plating, is an industrial activity where PFAS -containing mist suppressants may have been used. PFAS were sometimes used during the chromium electroplating process as a surfactant in chromic acid baths. Federal facilities where electroplating may have been conducted include Department of Defense installations where aircraft, heavy equipment, and ships were overhauled and maintained. Government-owned, contractor-operated research and development plants are also sites where electroplating operations have historically been conducted. 4.6.6 Landfill Operations, Waste Disposal Areas, and Wastewater Treatment Plants— Historically, landfills received wastes generated from government/military installations, including waste streams from operational areas (machine shops, electroplating operations, etc.), housing areas, and waste from wastewater treatment plants. These waste streams may contain industrial and/or consumer products that were either manufactured with PFAS or contain compounds that, when they degrade, release PFAS , which may leach out of the landfill . Additionally, waste material biosolids and sludge from WWTPs can contain PFAS . 4.7 Commercial and Industrial Uses of PFAs: 4.7.1 Uses of PFAS in commercial applications are varied and span numerous commercial and industrial sectors (Gaines 2022) ( 3 ) . This guide is focused on potential sources of significant releases of PFAS to the environment. Some examples of industries where PFAS have been used in production and manufacturing include: 4.7.1.1 Chemical industry with a special focus on processing aids in the polymerization of fluoropolymers, 4.7.1.2 Surface protection of textile, apparel, leather, carpets, and paper, 4.7.1.3 Electronics industry (semiconductors and wire; NAICS 334400 and 335929, respectively) (Note: and solar panels), 4.7.1.4 Consumer and personal care products, 4.7.1.5 Food processing and packaging, 4.7.1.6 Plastics and rubber production, 4.7.1.7 Pulp and paper industry, 4.7.1.8 Coatings, paints, and varnishes, 4.7.1.9 Refinery and petrochemical industry, 4.7.1.10 Munitions and explosives production, 4.7.1.11 Aircraft and heavy equipment manufacturing, 4.7.1.12 Public-sector and private-sector airports, and 4.7.1.13 Electroplating of parts and components. 4.7.2 As noted in section 4.6.5 , electroplating, specifically hard chromium plating, is an industrial activity where PFAS -containing mist suppressants may have been used. PFAS were sometimes used during the chromium electroplating process as a surfactant in chromic acid baths. 4.7.3 Chemical industry with a special focus on processing aids in the polymerization of fluoropolymers. Important uses of PFAS in the chemical industry are their uses as processing aids in the polymerization of fluoropolymers, the production of chlorine and sodium hydroxide, and the production of other chemicals including solvents . PFAS that are used as processing aids in the polymerization of fluoropolymers are of special concern due to emissions and toxicity (Lohmann, 2020) ( 5 ) . 4.7.4 Surface Protection of Textile, Apparel, Leather, Carpets, and Paper— Considerable quantities of PFAS , especially of side-chain fluorinated polymers, have been used as surface protectors in textile, apparel, leather, carpets, and paper. Paper products that may contain PFAS include food wrapping, pizza boxes, microwave popcorn. These are open and dispersive uses where many consumers come into contact with the PFAS -containing products. The side-chain fluorinated polymers contain perfluoroalkyl acids as impurities and they may act as important precursors to PFAS . Many PFAS precursors (such as alcohols, amides) can be degraded to perfluoroalkyl acids (OECD, 2007; Buck, R.C. et al. 2011 ( 6 ) ). Note 2: Toxicological and ecotoxicity assessments of perfluoroalkyl acids are in their nascent stage. 4.7.5 Electronics Industry— PFAS have been used as components in electronic devices (for example, in flat panel displays or liquid crystal displays). PFAS have also been used for the testing of electronic devices and equipment, as heat transfer fluids/cooling agents, in cleaning solutions, to deposit lubricants, and to etch piezoelectric ceramic filters. PFAS are also used in the production of semiconductors and wiring. 4.7.6 Plastics and Rubber Production— PFAS have been used as mold release agents, foam blowing agents, foam regulators, polymer processing aids, plastic etching agents, anti-blocking agents for rubber, and curatives in the production of plastic and rubber. Fluoropolymers can increase the processing efficiency and quality of plastic and rubber. The use of PFAS in the production of plastic and rubber may explain why PFAS are found in final products, for example, in artificial turf. 4.7.7 Coatings, Paints, and Varnishes— Large amounts of fluoropolymers have been used in coatings and paints to impart oil- and water-repellency. Fluoropolymers are also used as anti-stick and anticorrosive coatings. 4.7.8 Refineries and Petrochemical Industries— As noted previously, AFFF containing PFAS has been used for fire suppression at petroleum refineries, petrochemical manufacturing operations, and bulk storage and distribution terminals. The fire suppression systems at these facilities are subject to period testing. Fire suppression water containing AFFF may collect in holding ponds prior to being processed in the plant’s WWTP or discharged. 4.7.9 Munitions and Explosives Production— PFAS is used in a small percentage of energetics as binders and oxidizers, and in some military munitions for liners, o-rings, or other components (SERDP 2020) ( 7 ) . Manufacturers of munitions have historically released PFAS through open-burning of munition waste. 4.7.10 Aircraft and Heavy Equipment Manufacturing— Industries that use electroplating in the production and manufacturing of parts and equipment may have used PFAS -containing chemicals. 4.7.11 Public-Sector and Private-Sector Airports— AFFF containing PFAS has been used for fire suppression training at certain airports, including the bulk fuel storage tanks. The fire suppression training using AFFF is conducted periodically at airports. Fire suppression water containing AFFF may collect in holding ponds prior to being processed in the airport’s on-site WWTP , discharged to stormwater conveyance systems, or flow to an off-site WWTP . 4.7.12 Carwashes— PFAS are a component of the soap and waxes at commercial car washes (NAICS code 811192). Sumps and catch basins at a carwash that have lost their structural integrity may be a source of releases .