The 1st technical meeting of the EC-UNEP project in plastic pollution in aquatic environments took place at the European Commission Charlemagne building, on the 3rd and 4th of September 2024. Over 20 participants attended the event, including working group members, project staff, and UNEP and EC representatives (full list on annex 1). The agenda was arranged around five main sessions -Background session, Toolkit discussion, Data session, MFA discussion and Other Source categories discussion-, and participants and project staff engaged in interesting conversations around different topics of plastic pollution modelling, as detailed in the next sections. For full agenda and meeting notes, please refer to annexes 2 and 3.