We established the European Registry of Materials (nanocommons.github.io/identifiers/) in April 2019, allowing us to create global, unique identifiers to track nanomaterials used in individual research projects with minimal required information upfront. This provides users with full control over when to disclose or otherwise provide additional information on specific nanomaterials and accompanying physico-chemical and toxicological data. It allows users to discuss nanomaterials in a FAIR way, even before the detailed chemistry of the nanomaterials has been established. At the time of writing, six nanosafety projects have registered materials with the registry: NanoSolveIT, NanoFASE, RiskGONE, NanoTest, caLIBRAte, and SbD4Nano. Additionally, the European Gov4Nano project implemented these identifiers in several data reuse case studies, though no materials have been registered at the time of writing this paper.