The European Commission (EC) adopted on October 18, 2011, a Recommendation on the definition of a nanomaterial. The Recommendation “invites” member states, European Union agencies, and economic operators to use the following definition of nanomaterial “in the adoption and implementation of legislation and policy and research programmes concerning products of nanotechnologies”:

2.         “Nanomaterial” means 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 %.

3.         By derogation from point 2, fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm should be considered as nanomaterials.

The Recommendation states that, by December 2014, the EC will review the definition “in the light of experience and of scientific and technological developments. The review should particularly focus on whether the number size distribution threshold of 50 % should be increased or decreased.”

According to information on the EC website, it will use the definition primarily to identify materials for which special provisions might apply (e.g., for risk assessment or ingredient labeling). The EC notes:

Nanomaterials are not intrinsically hazardous per se but there may be a need to take into account specific considerations in their risk assessment. Therefore one purpose of the definition is to provide clear and unambiguous criteria to identify materials for which such considerations apply. It is only the results of the risk assessment that will determine whether the nanomaterial is hazardous and whether or not further action is justified.

The EC posted “[d]etailed and technical information” about the definition in a “Questions and Answers” document.