Table 1.

Some definitions, descriptions and criteria for nanomaterials as discussed in GSRS19.

Description	Definition or criteria	Source
EC recommended definition of nanomaterial	Nanomaterial is a natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50% or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm–100 nm. In specific cases and where warranted by concerns for the environment, health, safety or competitiveness the number size distribution threshold of 50% may be replaced by a threshold between 1 and 50%. By derogation […] fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm should be considered as nanomaterials.	European Union (2011): 2011/696/EU
Guidance for Industry Considering Whether an FDA-Regulated Product Involves the Application of Nanotechnology	FDA will ask: 1.Whether a material or end product is engineered to have at least one external dimension, or an internal or surface structure, in the nanoscale range (approximately 1 nm–100 nm); 2.Whether a material or end product is engineered to exhibit properties or phenomena, including physical or chemical properties or biological effects, that are attributable to its dimension(s), even if these dimensions fall outside the nanoscale range, up to 1 μm (1000 nm).6	FDA (2014): http://www.fda.gov/Regulatory Information/Guidances/ucm257698.htm Docket number (FDA-2010-D-0530)
US-EPA	…chemical substances that are solids at 25 °C and atmospheric pressure and that are manufactured or processed in a form where the primary particles, aggregates, or agglomerates are in the size range of 1–100 nm (nm) and exhibit unique and novel characteristics or properties because of their size. The proposed rule would apply to chemical substances containing primary particles, aggregates, or agglomerates in the size range of 1–100 nm in at least one dimension.	Federal Register/Vol. 82, No. 8, 3641 (2017)
ISO definition of nanomaterial	Nanomaterial: material with any external dimension in the nanoscale or having an internal structure or surface structure in the nanoscale	ISO/TR 18401:2017(en)
REACH definition of nanoform	On the basis of the Commission Recommendation of October 18, 2011 on the definition of nanomaterial, a nanoform is a form of a natural or manufactured substance containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50% or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm–100 nm, including also by derogation fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm.	COMMISSION REGULATION (EU) 2018/1881 (amending REACH)