On October 18, the European Commission released its long-awaited and much-debated recommendation for a regulatory definition for nanomaterials.  The major aspects of this definition are as follows:

  • “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.
  • Fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm should be considered as nanomaterials.
  • 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 %.
  • A material should be considered as falling under the definition…where the specific surface area by volume of the material is greater than 60 m2 / cm3.  However, a material which, based on its number size distribution, is a nanomaterial should be considered as complying with the definition…even if the material has a specific surface area lower than 60 m2/cm3.

It is important to note that the Commission’s proposed definition is a recommendation, addressed to Member States, Union agencies, and economic operators to follow when adopting legislation and implementing policy and research programs concerning the products of nanotechnologies.

In comparison with the draft recommendation, published almost a year ago, the final definition explicitly extends the scope of nanomaterials to all natural and incidentally formed materials.  As such, substances which are not intentionally engineered for their unique nano related properties are now also covered.  However, the definition is restricted to unbound particles and their aggregates and agglomerates, as opposed to the original draft recommendation also covering materials with internal or surface structures in the nano range.

Past comments made by EC Joint Research Center (JRC) in its 2010 “Considerations on a Definition for Regulatory Purposes” have pointed out the difficulties in relying upon a size-specific regulatory definition for nanomaterials.  Specifically, JRC said that “[there is no direct, material-independent relationship between size and novel effects or functions.”  Nonetheless, the Commission has crafted a definition “based solely on the size of the constituent particles of a material, without regard to hazard or risk.”  In addition, it has crafted a size-specific definition which relies upon a “number size distribution threshold” of 50%.  This is a significant change from the previous draft recommendation and the 2010 JRC report, which suggested a 1% threshold—a threshold which would have captured a very large quantity of substances with incidental fraction of particles in the nano range.  

Under the present definition, a mixture of heterogeneous particles will be considered a “nanomaterial.” At least 50% of these particles are in the 1-100 nm size range,which can be considered an arbitrary threshold which will be increased or decreased depending on further scientific progress.  It should be noted that the Commission intends to revisit all aspects of this definition “in the light of experience and of scientific and technological developments” by December 2014.