What are nanomaterials?

The European Commission has proposed a definition of nanomaterials to be used in regulations. In this definition the nanoscale size-range is between 1 and 100 nm and because nano-objects may have different shapes, the EU-definition refers to the minimum diameter of the nano-objects. – For example the thickness of a fiber or a flake; not its length.
A material is a nanomaterial if it contains 50% nano-objects or more by number.

The proposed European Commission nanomaterial definition refers to both manufactured, natural, and incidental nanomaterials.

Manufactured nanomaterials; also called substances on nanoform in the European chemicals regulation; may consist of a single pure element (e.g., silver and gold) or a compound (e.g., TiO2 and (Zn,Ni)Fe2O4) and occur in many different shapes, which again may contain chemical doping or surface chemical modifications or coatings.

Therefore, materials, and nanomaterials in particular, can comprise a large group of chemically partially similar materials with very different properties and potential hazards.

The EUoN website lists more than 300 manufactured nanomaterials which have been registered for use in different industries (https://euon.echa.europa.eu/da/search-for-nanomaterials)

Many additional types of nanomaterials and modifications are studied in dedicated research for potential development and use in products.