The European Chemicals Agency (ECHA) recently held a two-day workshop concerning its first experiences with nanomaterials under the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) program, with an emphasis on the evaluation process. ECHA, Member State Competent Authorities (MSCA), accredited stakeholders, and the European Commission (EC) discussed how nanomaterials in general have been characterized in registration dossiers. Currently, according to ECHA, the scope of the registration (i.e., whether and how many nano-forms are included) is often unclear and the level of nano-specific information provided (e.g., substance characterization, hazards, exposure, and risks) shows “significant room for improvement.” ECHA agreed with MSCA representatives on a common approach to addressing the current information requirements in nanomaterial dossiers, taking into account the scientific uncertainties and legislative framework provided by REACH. ECHA states that it will implement the EC’s recommendation on the definition of a nanomaterial as a benchmark in assessing substances, and “invites registrants to proactively characterise their substances in light of this definition.” Workshop participants discussed creating a working group on nanomaterials that would provide advice on scientific and technical principles related to nanomaterials under REACH. The working group on nanomaterials would act independently, but report to the relevant ECHA committees. According to ECHA, the mandate of this working group will be further consolidated with the MSCAs. In addition, ECHA intends to disseminate the best practices that it has collected from relevant stakeholders that registered nanomaterials and that were discussed in the first “Group Assessing Already Registered Nanomaterials” meeting prior to the workshop. ECHA intends to post the best practices on its website by this summer.