ASTM E3144-19

5.1 A nano-object is an individual, well-defined, and separable piece of a nanomaterial; in practice, nanomaterials used in research, products, testing, and other uses are usually collections of nano-objects. Individual nano-objects and collections of nano-objects are the two major types of nanomaterials in use. The description of an individual nano-object is covered in this guide; the description of collections of nano-objects (for example, two or more individual nano-objects) is not covered in this guide.

5.2 Nanomaterials are of growing importance in research and commerce, and data on their physical and chemical characteristics are critical to predict performance, to transact commercial activities, to assess their potential for harm to human and animal health and the environment in general, and to support regulations that affect their use. To describe nanomaterials, whether for research or commerce, it is important to be able to describe an individual nano-object.

5.3 When in a liquid environment, a nano-object may attract a non-permanent “halo” of water or other solvent molecules; such a non-permanent halo is not described by the present guide.

5.4 In contrast, coatings and coronas are semi-permanent or permanent adherents on time scales commensurate with testing procedures; coatings and coronas can fundamentally transform one nano-object to another in terms of its characteristics and can be described using this guide.

5.5 The four types of data and information used to describe a nano-object are: physical and chemical characteristics; production; specifications; and general identifiers (names and classifications), as shown in Fig. 1.

5.6 This guide deals solely with data and information to describe the physical and chemical characterization of an individual nano-object.

5.7 In a practical sense, the amount of data and information reported to describe the physical and chemical characteristics differs widely depending on who is reporting and the reason they are reporting. Researchers examining specific aspects of a nano-object may choose to report a limited subset of characteristics. A test report on the potential toxicity of a nano-object may choose to report numerous characteristics. This guide supports both limited and complete reporting of the characteristics enumerated herein.

5.8 The science of characterizing nano-objects is still evolving. Some information categories will require additional descriptors as new knowledge is developed. Some descriptors may become obsolete. Users should consult the latest guide for the most complete recommendations.

5.9 The technology for collecting, storing, analyzing, and disseminating scientific and technical data continues to evolve, and tools such as ontologies, database schemas, data repository reporting requirements, and data recoding formats are evolving similarly. This guide provides a clear, English language definition of information categories and descriptors used to describe an individual nano-object that can be used in these and other similar tools.

5.10 A nano-object has properties and functionalities that are measured under specific measurement conditions. The description of a nano-object requires data and information on its properties as well as on the conditions under which those properties were measured, as shown in Fig. 2. The description of the data and information necessary to describe properties and functionalities as well as the procedure, which specify the measurement conditions under which the properties and functionalities are measured, are described in other guides and standards.

5.11 The characteristics of an individual nano-object defined in this guide address the important physical and chemical properties of that nano-object. Because the techniques and instruments used to measure these properties can greatly influence the property value, when available, the measurement result being used should include as much information as possible about the measurement conditions.

1.1 This guide provides guidelines for a description system for reporting the physical and chemical characteristics of individual nano-objects. It establishes information categories and descriptors useful in describing individual nano-objects uniquely and such that the equivalency of two or more individual nano-objects can be determined according to specific criteria.

1.2 This guide is designed to be directly applicable to reporting the physical and chemical characteristics of nano-objects in every circumstance, including but not limited to reporting original research results in the archival literature, developing ontologies, database schemas, data repositories, and data reporting formats, specifying regulations, and enabling commercial activity.

1.3 This guide is applicable to naturally-occurring, engineered, and manufactured nano-objects.

1.4 One goal of the guide is to help ensure that when measurement results are reported, they are reported uniformly.

1.5 A second goal of the guide is to encourage reports on the properties and functionalities of a nano-object to include as much detail as possible about the physical and chemical characteristics of that nano-object so it is uniquely specified.

1.6 This guide does not cover the chemical reactions or reactivity of a nano-object.

1.7 The values stated in SI units are to be regarded as 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.