Since 2011, the European commission had provided a recommendation of definition for nanomaterials in Europe.
The United States and Australia have recently launched their own definition.
Some sectors in Europe have also defined a definition introducing slight differences or additional characteristics.
The current regulatory context across Europe and also worldwide is therefore heterogeneous and rapidly evolving.
The impact of this regulatory situation on the toxicological and environmental evaluation of nanomaterials will be presented using examples of nanomaterials used for decades and recently developed ones.