Nanomaterials are chemical substances or materials that are manufactured and used at a very small scale. Nanomaterials are developed to exhibit novel characteristics compared to the same material without nanoscale features, such as increased strength, chemical reactivity or conductivity.
ISO (2015) defines a nanomaterial as a:
‘material with any external dimension in the nanoscale (size range from approximately 1 – 100 nm) or having internal structure or surface structure in the nanoscale’.
In 2011, the European Commission released a specific recommendation on the definition of a nanomaterial (EC, 2011) which should be used in European Regulations, including REACH and CLP. According to this Recommendation, a “nanomaterial” means:
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.