In this letter, Hermann Stamm, with the European Commission Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy, takes issue with Andrew Maynard’s article in the journal Nature, in which Maynard argued against defining engineered nanomaterials for regulatory purposes. Stamm says, “…such a definition is urgently needed, especially for particulate nanomaterials. The aim should be to identify a general class of materials for attention — whether they are benign or hazardous.” While conceding Maynard’s point that nanomaterials are heterogeneous is justified, he argues that they all have structures on the nanoscale, which modify their other properties. Size is then, says Stamm, the most appropriate parameter on which to base a broad definition, adding, “A definition is required for labelling purposes, and would assist industry and regulators in identifying where specific safety assessments might be necessary. We acknowledge that it would need revision in line with fresh scientific evidence.”
http://www.nature.com/nature/journal/v476/n7361/full/476399c.html