As reported in our June 19, 2017, blog item, the European Commission (EC) published a catalog of nanomaterials used in cosmetic products on the European Union (EU) market. On February 5, 2018, the European Union Observatory for Nanomaterials (EUON) published a table linking nanomaterials listed in the catalog to their Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) registration data in the European Chemicals Agency’s (ECHA) database. According to EUON, the linking was done by matching chemical substances in ECHA’s database through their Chemical Abstracts Service (CAS) numbers and/or with the name of the nanomaterial in the catalog. EUON notes that as the registration of nanomaterials under the Cosmetics Regulation and the registration of substances under REACH have different scopes, it is not always possible to have a perfect match. Some catalog entries are more specific in scope than the substances registered under REACH. EUON cautions that a REACH registration may not specifically cover the nanoforms of the substances used in cosmetics.