The definition adopted by the Commission is based on the size of the constituent particles of a material. The wording describes a nanomaterial as "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."

According to the European Commission, a clear definition was needed to ensure that the appropriate chemical safety rules apply.

"I am happy to say that the EU is the first to come forward with a cross-cutting designation of nanomaterials to be used for all regulatory purposes. We have come up with a solid definition based on scientific input and a broad consultation. Industry needs a clear coherent regulatory framework in this important economic sector, and consumers deserve accurate information about these substances. It is an important step towards addressing any possible risks for the environment and human health, while ensuring that this new technology can live up to its potential," commented European Environment Commissioner Janez Potočnik.

Criticism on the distribution threshold

A draft version of the definition was subject to a public consultation, and the Commission says the definition is based on scientific advice from the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) and the Joint Research Centre (JRC).

However, while the SCENHIR suggested to classify as nanomaterial any substance containing at least 0.15% of nanoparticles, eventually put the threshold at 50%.

BEUC, the European Consumer’s Organisation, as well as the European Environmental Bureau (EEB), said they were disappointed and surprised by the shift of threshold from 0.15% to 50%, which they consider will exclude too many substances from the scope of the definition.

The Commission said the decision to deviate from this threshold value was made for practical considerations. “Nanoparticles are present in low quantities in most solid materials. The percentage may be significant, in particular in certain powders. Therefore, a threshold of 0.15% could include too broad a range of materials within the definition, and would have made it difficult to tailor regulatory provisions appropriately. The choice of 50 % is based on the attempt to distinguish nanomaterials which may exhibit specific novel properties from conventional chemical substances.

As far as the chemicals industry is concerned, Cefic deems on the contrary that the definition is too broad in scope and therefore difficult to integrate into existing legislation in a meaningful way

What about cosmetics?

Regarding cosmetics, the new Regulation (EC) No 1223/2009 of 30 November 2009 on cosmetic products already provides a definition of nanomaterials [1], which significantly differs from the one the Commission just adopted.

In practice, earlier definitions, developed on a case-by-case basis and which vary across sectors, will nevertheless remain applicable in their respective areas, as long as these texts will not be updated by the legislator. However, the Commission may decide to propose some legal updates where deemed necessary, this should be the case in particular for REACH.

Otherwise, the Commission intends to use the definition in new proposals and applied it in a flexible way. For instance, in case of specific concerns related to the environment, health, safety or competitiveness, a lower threshold for the number size distribution of nanoparticles may be used.

The definition will be reviewed in 2014 in the light of technical and scientific progress.

Commission Recommendation of 18 October 2011 on the definition of nanomaterial