The European Commission Joint Research Centre (JRC) has today published a comprehensive report on concepts and terms used in the European Commission's definition of nanomaterial. The report 'aims to provide clarifications of the key concepts and terms that are used in the EC NM definition, and discusses them in a regulatory context.'

The European Commissionfrom  2011 (2011/696/EU) definition is a recommendation that has been used to create legal definitions in several sector specific EU legislations such as in the Biocidal Products Regulation, Medical Devices Regulation, and in the recent revised REACH annexes (EU) 2018/1881). The recommendation has also been used in several EU national schemes.

The report discusses concepts and terms such as particle, size and how this dimension can be measured, the difference between a nanomaterial vs a nanostructured material, constituent particles, volume specific surface area (VSSA), particle number-based particle size distribution, aggregates and agglomerates, nanomaterials in products and stresses the importance of appropriate sample preparation to generate accurate measurement results. 

The report also states that 'Nanomaterials are not necessarily hazardous and a definition based only on size properties cannot differentiate between hazardous and non-hazardous materials.'