Here we describe a recent initiative of several EU NanoSafety Cluster projects to establish such an identifier for use within projects and beyond, modelled on similar efforts in the pharmaceutical industry. In the case of pharmaceuticals, chemicals reported by a company receive an identifier, without the need to disclose their structures . This identifier can be used in, for example, clinical trials and publications, thus linking data to the unique registry number for the specific chemical as information becomes public . Applying this approach to nanomaterials and nanosafety research, the projects compile the list of nanomaterials that they will use and "register" these on behalf of the project. Each nanomaterial then receives an identifier, that may be accompanied by additional information such as supplier, composition, size and batch number, or can be simply a placeholder that does not disclose their structure or composition. This identifier can be used in, for example, project (deliverable) reports and subsequent publications. At some point the chemical structure is disclosed and the identifier is linked to the identity of the material. While this expectation is not explicitly required, releasing data is the default for European Horizon 2020 projects.