RIVM considers this definition to be a good basis for further discussion that should focus on two aspects of the definition: the proposed size limits for nanoparticles (1 to 100 nanometres); and the requirement that at least 50% of the number of particles should be in this size range. According to RIVM, further scientific research would contribute to better understanding the implications of these threshold values. In addition, reliable and standardised measurement techniques are needed to determine particle number and size distributions. The European Commission will review the definition in 2014 in the light of experience and developments in science and technology.
In recent years, an increasing number of applications and products containing or using nanomaterials have become available. However, the small size of the particles in nanomaterials gives these materials different properties relative to materials with larger sizes. A unequivocal definition of the term 'nanomaterial' is essential in EU legislation and regulations, particularly with regard to the management of potential risks of nanomaterials to humans and the environment.
Once the definition of a nanomaterial has been established, it has to be incorporated in the appropriate legislative frameworks. Subsequently, further amendments may be required with regard to specific provisions for certain types of nanomaterials to ensure safe use.
RIVM agrees with the Commission's principle that a nanomaterial should not automatically be considered as hazardous. Conversely, materials not covered by the definition should not automatically be considered as safe. Such materials may pose a nano-sized related risk, if a substantial number of the particles is in the nano-size range, depending on the degree of human and environmental exposure.