The revision process for the definition of a nanomaterial has concluded with the publication of the updated definition.
First adopted in 2011, the definition provides a reference for EU legislation containing specific nanomaterial provisions; over the last several years, the Commission has been assessing the fitness for purpose of the definition, and its Joint Research Centre (JRC) performed three studies covering i) the collected practical experiences of application of the definition; ii) an assessment of those experiences; and iii) a scientific and technical evaluation of the potential options to clarify the definition and facilitate its implementation.
Based on the interim JRC findings, the Commission launched a stakeholder consultation in June 2021 (see the NIA contribution here), focusing in particular on particle aspects (consideration of particles with dimensions outside 1-100 nm, generalization from the derogation of fullerenes, single-wall carbon nanotubes, and graphene flakes); the flexibility of the particle number concentration threshold; and the reference to Volume Specific Surface Area (VSSA).
The final definition can be found at this link. It is accompanied by a Staff Working Document outlining the revision process as well as the rationale behind the changes made. It will be further complemented by a guidance document to be released by the end of the year.

An NIA factsheet is available to all members, providing a quick recap of the process and the changes made.