Experts within the WGs collaborate to consolidate knowledge and scientific consensus on their topic of expertise that can be used to guide stakeholders and negotiators involved in the Plastic Treaty Negotiations. Upon requests from government and international organizations, a WG can also provide feedback and opinions on specific matters relevant for its topic.
Membership in the WGs is voluntary. Two preconditions apply for membership:
1) Specific and documented expertise, and 2) a Declaration of Interest
Beyond these preconditions, the WGs are inclusive and will seek to ensure global representation of scientists, and balance across age, gender and geographic location. The Secretariat and Steering Committee monitor and actively contribute to achieve balance by following up on the WGs and taking action to broaden membership in the WGs together with the WG members and especially the chair and co-chair.
WGs are coordinated by a chair and co-chair elected by the working group members. The chair and the co-chair must both be core members. The role of the chair and co-chair is to coordinate the work under the working group and ensure progression. The working groups are free to determine the topics of investigation and levels of outputs.
| Working group | Co-chairs |
| WG1. Upstream measures and impacts | Nihan Karali, Lawrence Berkeley National Laboratory
Doris Knoblauch, Berlin Ecologic Institute |
| WG2. Circular Economy | Kristian Syberg, Roskilde University
Jane Muncke, Food Packaging Forum |
| WG3. Polymers, chemicals and products of concern | Martin Wagner, Norwegian University of Science and Technology
Susanne Brander, Oregon State University |
| WG4. Waste management and existing plastics pollution | Patrick O’Hare, University of St. Andrews |
| WG5. Indigenous and Traditional knowledge | Rufino Varea, University of the South Pacific |
| WG6. WTO dialogue on plastic pollution (DPP) | Trisia Farrelly, Massey University
Richard Thompson, University of Plymouth |
| WG7. Food System Plastics | Joe Yates & Megan Deeney, London School of Hygiene & Tropical Medicine |
In addition to the above working groups, Scientists’ Coalition members have organized in ad-hoc working groups in response to the ongoing negotiations, producing scientific outputs to inform the process on topics including:
| 2025 Priority Area working groups | Co-chairs |
| Products and Chemicals | Susanne Brander, Oregon State University
Martin Wagner, Norwegian University of Science and Technology |
| Supply and Production of Plastic Precursors Reduction | Kristian Syberg, Roskilde University
Andreas Arias, Argentinian Institute of Oceanography, National South University, Argentina |
| Emissions/Releases | Marie-France Dignac, French National Research Institute for Agriculture, Food and the Environment
Florin-Constantin Mihai, Alexandru Ioan Cuza University of Iasi |
| Finance | Noreen O’Meara, University of Surrey
Natalia de Miranda Grilli, University of Tasmania |
| Human Health | Jane Muncke, Food Packaging Forum
Megan Deeney, London School of Hygiene & Tropical Medicine |
| Product Design | Winnie Courtene-Jones, Bangor University
Jean-François Ghiglione, Centre National de la Recherche Scientifique |
Each WG member signs a declaration of interest declaring their commitment to work exclusively in the public interest in a way that is free from conditioning by particular interest and ideology. When applying to join a working group, candidates disclose their interests and report any situation that may configure a conflict of interest.
The interaction between the working groups and stakeholders (e.g., in cases in which a specific opinion is required from the working groups) takes place in an open fashion. The secretariat keeps records of Coalition interactions with the Intergovernmental Negotiating Committee (INC) and Member States.
The work within each working group is conducted in an open way, where experts cooperate to reach consensus among peers that will be reflected in the perspectives, indications and recommendations provided to stakeholders and negotiators.
The peer-review process and the elaboration of documents by working groups is open, traceable and documented.