In recent years, an increasing number of applications and products containing or using nanomaterials have become available. Knowledge on potential risks of these materials for humans and the environment is currently insufficient. By publishing the “Recommendation on the definition of nanomaterial” in October 2011, the European Commission has taken an important step towards risk assessment of nanomaterials.

The National Institute of Public Health and the Environment (RIVM) of the Netherlands has published a report which examines the European Commission’s definition of ‘nanomaterial’.

The Commission recommends that a nanomaterial is defined as a material in which at least 50% of the number of the constituent particles is in the size range 1 - 100 nm.

The RIVM considers this definition as a proper basis for regulation. Nevertheless, several scientific issues have been identified that need attention in the implementation of the definition in legislative frameworks. These issues include:

  • Are current measurement techniques for chemicals suitable for nanomaterials? There is a great variety of measurement techniques and methods available, but at present it is not clear what the most suitable technique for each case is.
  • In which part of the life-cycle, from production to use, will materials be examined to fulfill the criteria of the definition? It will not be sufficient to determine only once in the life-cycle whether a material is a nanomaterial, because the size of particles (including nanoparticles) can change during the life-cycle.
  • What does the definition reveal about environmental, health and safety risks of nanomaterials? The current definition is based on a percentage of the particles that is smaller than 100 nm and is not aimed at mapping out the risks of nanomaterials. The choice for this size limit is pragmatic and lacks a solid scientific basis. To enable a proper risk assessment, further insight is needed into the relationship between the particle size of materials and their effects on environmental and human health.