1.1 本指南描述了用户可以采取的行动，以最大限度地减少人类在研究、制造、实验室和其他职业环境中接触未结合的工程纳米颗粒（UNP），而这些职业环境中可能合理地存在UNP。其目的是为控制此类暴露提供指导，作为既不存在相关暴露标准，也不存在明确的危险和暴露信息的警告措施。 1.2 一般指南- 本指南适用于可能合理预期UNP存在的职业环境。在与纳米级粒子暴露控制相关的特定方面，这些设置的操作将有很大差异。UNP代表各种物理和化学特性（例如，形态、质量、尺寸、化学成分、沉降速度、表面积、表面化学）和使用环境。鉴于各种UNP呈现的物理和化学特征的范围、职业环境的多样性以及处理UNP材料的经验知识和经验的不均衡性，本指南的目的是基于观点的共识，为UNP的暴露最小化方法提供一般指导，但不要建立标准做法，也不要建议在所有情况下都要遵循的明确行动方针。 1.2.1 因此，并非本指南的所有方面都与UNP处理的所有情况相关或适用。用户在应用本指南时应作出合理判断，包括考虑所涉及的特定UNP的特征、用户的工程和其他材料经验，以及用户可能应用本指南的特定职业设置。鼓励用户在应用本指南时获得合格专业人员的服务。 1.2.2 适用于不存在相关暴露标准的情况- 本指南假设用户了解并遵守适用于散装UNP的任何权威职业暴露标准。如果不存在此类暴露标准，或存在此类标准，但未考虑材料的纳米级形式，则本指南可能适用。 1.3 适用于不存在稳健风险信息的情况- 本指南假设缺乏与所涉及的特定UNP相关的科学合理的风险评估信息。如果存在或即将存在可靠的风险评估信息，则应根据该信息设计任何暴露控制措施，而不是以本指南为前提。此类措施可能比本指南建议的措施更严格或更不严格。 1.4 范围内的材料- 本指南适用于未结合的工程纳米颗粒或其可呼吸的团聚体或聚集体。相关的纳米颗粒类型包括，例如，有意生产的富勒烯、纳米管、纳米线、纳米绳、纳米带、量子点、纳米金属氧化物和其他工程纳米颗粒。可呼吸颗粒是指空气动力学等效直径（AED）小于或等于10µm（10 000 nm）或那些小到足以用可呼吸取样器收集的颗粒 ( 1- 3. ) . 2. AED描述了 行为 取决于颗粒密度、形状和尺寸，例如，球形、光滑表面、密度为1.0 g/cc、物理直径为4µm的颗粒的AED为4µm，而球形、光滑表面的颗粒，密度为11.35 g/cc、物理直径为4µm时，AED为14µm，因此尺寸不可呼吸。可呼吸纤维是指物理直径小于或等于3µm（3000 nm）的纤维或小到足以用胸部采样器采集的纤维 ( 4. , 5. ) . 1.5 超出范围的材料: 1.5.1 UNP可以以各种形式存在，例如粉末或悬浮液，或作为初级颗粒的团聚体和聚集体，或作为分散在基质中的颗粒。本指南不适用于在特定使用情况下（例如，分散或以其他方式固定在固体中、牢固结合在基质上或包含在液体基质中（如油漆中颜料的聚合初级晶体）中，无法作为实际事项在空气中传播或预期在职业环境中生成或释放UNP的UNP。 本指南不适用于非可吸入尺寸的UNP骨料或团块。 1.5.2 本指南不适用于呈现纳米级表面特征的材料，但不包含UNP（例如，纳米级光刻产品、纳米电子结构或由纳米级层组成的材料）。 1.5.3 本指南不适用于自然界中存在的UNP，这些UNP可能存在于正常环境大气中，或由人类活动（如燃烧过程）无意产生。它也不适用于已制定暴露控制计划（例如，纳米级生物制剂的安全处理协议）或已公布的暴露极限（例如焊接烟雾的职业暴露极限）的材料。看见 附录X1 . 1.6 处理超出范围的注意事项- 本指南的使用仅限于本节规定的范围。本指南通常不涉及与潜在环境风险相关的行动，也不涉及处置或其他目的可能产生的风险- 使用。 1.7 不是护理标准- 本指南不一定代表用于判断一组暴露控制措施是否充分的谨慎标准；在使用本文件时，不得未考虑其可能适用的特定材料和职业环境。标题中的“标准”一词仅表示该文件已通过ASTM共识程序获得批准。 1.8 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。 1.9 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、健康和环境实践，并确定监管限制的适用性。 1.10 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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本指南旨在供涉及在职业环境中处理UNP的实体使用。本指南涵盖了适用于各种UNP材料和搬运设置的搬运原则和技术。这些设置包括研发活动、材料制造以及材料使用和加工。本指南也可用于接收含有或包含固定在基质上或基质内的纳米颗粒（即结合的纳米颗粒）的材料或物品的实体，但其自身的过程或使用可能合理预期会导致此类颗粒变得不结合。

1.1 This guide describes actions that could be taken by the user to minimize human exposures to unbound, engineered nanoscale particles (UNP) in research, manufacturing, laboratory and other occupational settings where UNP may reasonably be expected to be present. It is intended to provide guidance for controlling such exposures as a cautionary measure where neither relevant exposure standards nor definitive hazard and exposure information exist. 1.2 General Guidance— This guide is applicable to occupational settings where UNP may reasonably be expected to be present. Operations across those settings will vary widely in the particular aspects relevant to nanoscale particle exposure control. UNP represent a vast variety of physical and chemical characteristics (for example, morphology, mass, dimension, chemical composition, settling velocities, surface area, surface chemistry) and circumstances of use. Given the range of physical and chemical characteristics presented by the various UNP, the diversity of occupational settings and the uneven empirical knowledge of and experience with handling UNP materials, the purpose of this guide is to offer general guidance on exposure minimization approaches for UNP based upon a consensus of viewpoints, but not to establish a standard practice nor to recommend a definite course of action to follow in all cases. 1.2.1 Accordingly, not all aspects of this guide may be relevant or applicable to all circumstances of UNP handling. The user should apply reasonable judgment in applying this guide including consideration of the characteristics of the particular UNP involved, the user’s engineering and other experience with the material, and the particular occupational settings where the user may apply this guide. Users are encouraged to obtain the services of qualified professionals in applying this guide. 1.2.2 Applicable Where Relevant Exposure Standards Do Not Exist— This guide assumes that the user is aware of and in compliance with any authoritative occupational exposure standard applicable to the bulk form of the UNP. This guide may be appropriate where such exposure standards do not exist, or where such standards exist, but were not developed with consideration of the nanoscale form of the material. 1.3 Applicable Where Robust Risk Information Does Not Exist— This guide assumes the absence of scientifically sound risk assessment information relevant to the particular UNP involved. Where sound risk assessment information exists, or comes to exist, any exposure control measures should be designed based on that information, and not premised on this guide. Such measures may be more or less stringent than those suggested by this guide. 1.4 Materials Within Scope— This guide pertains to unbound engineered nanoscale particles or their respirable agglomerates or aggregates thereof. Relevant nanoscale particle types include, for example, intentionally produced fullerenes, nanotubes, nanowires, nanoropes, nanoribbons, quantum dots, nanoscale metal oxides, and other engineered nanoscale particles. Respirable particles are those having an aerodynamic equivalent diameter (AED) less than or equal to 10 µm (10 000 nm) or those particles small enough to be collected with a respirable sampler ( 1- 3 ) . 2 The AED describes the behavior of an airborne particle and is dependent upon the particle density, shape, and size—for instance, a particle with a spherical shape, smooth surface, density of 1.0 g/cc and a physical diameter of 4 µm would have an AED of 4 µm, whereas a particle with a spherical shape, smooth surface, density of 11.35 g/cc and a physical diameter of 4 µm would have an AED of 14 µm and would therefore be of a nonrespirable size. Respirable fibers are those having physical diameters less than or equal to 3 µm (3000 nm) or those fibers small enough to be collected with a thoracic sampler ( 4 , 5 ) . 1.5 Materials Beyond Scope: 1.5.1 UNP may be present in various forms, such as powders or suspensions, or as agglomerates and aggregates of primary particles, or as particles dispersed in a matrix. This guide does not pertain to UNP incapable, as a practical matter, from becoming airborne or be expected to generate or release UNP in occupational settings under the particular circumstances of use (for example, UNPs dispersed or otherwise fixed within a solid, strongly bonded to a substrate or contained within a liquid matrix such as aggregated primary crystals of pigments in paints). This guide does not pertain to aggregates or agglomerates of UNP that are not of a respirable size. 1.5.2 This guide does not pertain to materials that present nanoscale surface features, but do not contain UNPs (for example, nanoscale lithography products, nanoelectronic structures or materials comprised of nanoscale layers). 1.5.3 This guide does not pertain to UNPs which exist in nature which may be present in normal ambient atmospheres or are unintentionally produced by human activities, such as by combustion processes. Nor does it pertain to materials that have established exposure control programs (for example, safe handling protocols for nanoscale biological agents) or published exposure limits such as occupational exposure limits for welding fumes. See Appendix X1 . 1.6 Handling Considerations Beyond Scope— The use of this guide is limited to the scope set forth in this section. This guide generally does not address actions related to potential environmental exposures, nor to exposures potentially arising at disposal or other end-uses. 1.7 Not a Standard of Care— This guide does not necessarily represent the standard of care by which the adequacy of a set of exposure control measures should be judged; nor should this document be used without consideration of the particular materials and occupational circumstances to which it may be applied. The word “standard” in the title means only that the document has been approved through the ASTM consensus process. 1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.9 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. 1.10 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 This guide is intended for use by entities involved in the handling of UNP in occupational settings. This guide covers handling principles and techniques that may be applied, as appropriate, to the variety of UNP materials and handling settings. These settings include research and development activities, material manufacturing, and material use and processing. This guide may also be used by entities that receive materials or articles containing or comprising nanoscale particles fixed upon or within a matrix (that is, bound nanoscale particles), but whose own processes or use may reasonably be expected to cause such particles to become unbound.