On the 21st November ECHA hosted the 18th meeting of the Nanomaterial Expert Group in Helsinki, where technical issues relating to the implementation of REACH, CLP and the Biocidal Products Regulation (BPR) for nanomaterials were discussed. The discussion included a presentation on the strategy put forwards by the EU project NanoHarmony on how to prioritise OECD Test Guidelines and Guidance for Nanomaterials. Further input was requested under a survey (end date 31st December 2023) and which can be accessed through https://www.surveymonkey.com/r/maltainitiativeprioritylist