European Commission Adopts a Common Definition of "Nanomaterial"


On October 18, 2011, the European Commission officially adopted the definition of “nanomaterial” set out in its Recommendation.  In the Recommendation, “nanomaterial” is defined in the following manner.

  • “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 %.

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

  • For the purposes of the definition of “nanomaterial,” the terms ‘particle’, ‘agglomerate’ and ‘aggregate’ are defined as follows:

(a) ‘particle’ means a minute piece of matter with defined physical boundaries;

(b) ‘agglomerate’ means a collection of weakly bound particles or aggregates where the resulting external surface area is similar to the sum of the surface areas of the individual components;

(c) ‘aggregate’ means a particle comprising of strongly bound or fused particles.

Many members of the nanotechnology community will note with interest what the definition specifically includes and excludes by implication.  For example, the definition includes both natural and incidental materials, as well as aggregates and agglomerates of primary particles in the nanoscale (i.e, generally 1 – 100 nm).  The definition implicitly excludes materials having a surface or internal structure at the nanoscale; in other words, the definition is particle/object-focused.  Thus, the scope of the definition differs in important ways from those established by other members of the international community, such as the International Organization for Standardization’s Technical Committee 229  (ISO TC 229).  Also of interest will be the Commission’s decision to identify nanomaterials by particle number size distribution, which appears to be a reasonable approach to determining whether a material falls within the nanoscale, assuming reliable measuring techniques can be developed and standardized.

The Recommendation requires a review of the definition by December 2014 to ensure the definition remains adequate for its needs.  For example, the review will assess whether the number size distribution threshold of 50% should be increased or decreased and whether materials with nanoscale internal or surface structures should be included. 

With the adoption of a common definition for legislative, regulatory and policy purposes, the EU should achieve greater consistency in the way nanomaterials are identified for purposes of risk assessment and management.  Currently, there are several pieces of EU legislation (e.g., the Cosmetics Regulation, EU Regulation 1223/2009) and implementing guidance that either include a definition of “nanomaterial” or make reference to the term.  Consistency in how these materials are identified in the different regulatory areas should provide greater certainty and predictability for the regulated community and other stakeholders, and may even foster more innovation and increased confidence in safety claims and evaluations. 

Further information, including a Question & Answer document, is available here and here.