Nanoforms (NFs) of a substance may be distinguished from one another through differences
in their physicochemical properties. When registering nanoforms of a substance for
assessment under the EU REACH framework, five basic descriptors are required for their
identification: composition, surface chemistry, size, specific surface area and shape. To
make the risk assessment of similar NFs efficient, a number of grouping frameworks have
been proposed, which often require assessment of similarity on individual physicochemical …