On July 15, 2021, the European Union (EU) Observatory for Nanomaterials (EUON) published a Nanopinion entitled “The ECHA Nanomaterials Expert Group (NMEG)” by Frank Le Curieux, Scientific Area Leader for Genotoxicity at the European Chemicals Agency (ECHA). Le Curieux provides a brief summary of the creation of NMEG and its history. NMEG’s current mandate is to provide informal and non-binding scientific and technical advice on questions related to nanomaterials or nanoforms of substances in the frame of the implementation of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation, the Classification, Labeling and Packaging (CLP) regulation, the Biocidal Products Regulation (BPR), EUON, and other issues relevant to ECHA’s work. NMEG is intended to improve the understanding of specific issues concerning nanomaterials/nanoforms of substances, leading to more informed and efficient discussions within ECHA’s committees. In 2019 and 2020, ECHA paused NMEG’s work. In January 2021, the NMEG mandate was updated to align fully with the mandates for the Persistent, Bioaccumulative, and Toxic (PBT) and the Endocrine Disruptors expert groups. Le Curieux states that the main change is that an NMEG meeting will be organized only when critical scientific issues or operational issues have been proposed by one of the NMEG members and robust documentation is provided. Moreover, according to Le Curieux, the NMEG outcomes should be useful to support decision making, and the connection between NMEG, the Member State Competent Authorities, and ECHA committees should be ensured. Le Curieux suggests that NMEG could provide recommendations on specific dossier evaluation or substance evaluation cases that the Member State Committee may take into account in their decision making.