Public Consultation on Scientific Basis for a Definition of the Term "Nanomaterial"

In line with its procedures for stakeholder dialogue, published on 15 September 2007, the European Commission is launching a public consultation on the pre-consultation opinion approved by written procedure on 6 July 2010.

The services of the European Commission need to elaborate a working definition for the term “nanomaterial” to ensure the consistency of forthcoming regulatory developments to guide, as appropriate, the effective implementation of existing regulation and to contribute to international work and dialogue on nanotechnology definitions.

In order to prepare a science-based definition of nanomaterials, the services of the European Commission need clarification on the size ranges and other relevant characteristics and corresponding metrics reported in the scientific literature, the types of physical and chemical properties particular to nanomaterials, the relevant thresholds, as well as the most appropriate metrics to express such thresholds.

There is no scientific evidence in favour of a single upper limit. Moreover, there is no scientific evidence to qualify the appropriateness of the 100 nm value. Notably, defining the nanoscale as having a size between approximately 1 and 100 nanometre would not be without problems within a regulatory setting. There is a need for a more elaborate description to identify unequivocally a nanomaterial or a product containing a nanomaterial for various EU regulatory bodies.

The opinion provides advice on the essential scientific elements of a working definition for the term “nanomaterial” for regulatory purposes. Existing definitions formulated by various bodies are reviewed and discussed. Specific issues are addressed which need to be considered when a definition for nanomaterials has to be used in a regulatory setting.

By discussing various issues, several questions may be answered:

• When is a material a nanomaterial?
• Should there be a distinction based on the origin or application of the material?
• Is there a specific size (threshold) when a material changes its properties?

In order to define an enforceable definition of “nanomaterial” for regulatory use it is proposed to set an upper limit for nanomaterial size and to add to the proposed limit additional guidance (requirements) specific for the intended regulation.

Crucial in the guidance that needs to be provided is the extended description of the nanoscale. Merely defining single upper and lower cut-off limits is not sufficient in view of the size distributions occurring in manufactured nanomaterials. Although many nanomaterials are produced for specific properties at the nanoscale, at the moment it is not possible to identify a specific size or a specific generic property that is suddenly introduced or changed with size.

Alternatively, a tiered approach may be required depending on the amount of information known for any specifically engineered nanomaterial and its proposed use.

Source: European Commission