Impact statement

In the leadup to the second part of the fifth session of the Intergovernmental Negotiating Committee to negotiate a legally binding global plastics treaty INC5.2), the Scientists’ Coalition for an Effective Plastics Treaty (the Scientists’ Coalition’) herein provide independent evidence-based responses to selected articles of the ‘Chair’s text’: the latest draft of the treaty text currently under negotiation. The aim of the Scientists’ Coalition is to ensure treaty negotiations are guided by robust evidence-based science underpinned by conflict-of-interest mitigation policies and processes.

Dear editor-in-chief, Prisms Plastics

The future Global Plastics Treaty is an instrument positioned to end plastic pollution and to protect health, rights and the environment. The Scientists’ Coalition for an Effective Plastics Treaty has been following treaty negotiations and supporting member states with independent and robust scientific evidence since the first negotiating session in 2022 (INC-1). When the most recent draft of the treaty text (‘the Chair’s text’) was released on 1 December 2024, our members convened working groups around selected articles of the Chair’s text to offer science-based responses. This letter summarises those responses.

Definitions (article 2)

Clear definitions are an essential element of any Multilateral Environmental Agreement (MEA), as they ensure common understanding and shared language to reduce the potential for ambiguity and disagreement. Definitions (or a glossary of terms) were introduced into Plastic Treaty negotiations at INC-1 in 2022, and UNEA resolution 5/14 included definitions adopted or endorsed by intergovernmental processes (UNEP, 2022). Article 2 of the Chair’s text requires definitions that are clear and science-based to ensure that all parties understand and agree on the scope and interpretation of the text.

We propose that Article 2 contain a short list of key definitions to facilitate negotiations and that prior to the first conference of parties (COP), a substantive list of definitions be prepared by an expert group/subsidiary body, including agreed terms (e.g., from other MEAs), as appropriate. An expert group can ensure the development and regular updating of terms and definitions reflect the best available science (Scientists’ Coalition for an Effective Plastics Treaty, 2025e).

Chemicals and products of concern (article 3)

Strong scientific evidence links plastic chemicals to reproductive, neurodevelopmental, immune and metabolic disorders in humans (Symeonides et al., Reference Symeonides, Aromataris, Mulders, Dizon, Stern, Barker and Dunlop2024). However, existing MEAs, such as the Basel and Stockholm Conventions, lack the mandate and the scope to comprehensively and effectively regulate chemicals of concern (CoCs) in plastics across their full life cycle and supply chains (Wagner et al., Reference Wagner, Monclus, Arp, Groh, Løseth, Muncke, Wang, Wolf and Zimmermann2024). The regulation of CoCs in the plastics treaty is, therefore, essential to protect human and environmental health from the most harmful plastic chemicals, with substantial benefits for public health, health care systems and the environment.

A successful Article 3 would include the following core components: sufficient scope and criteria to address groups of CoCs in all plastics based on their hazards; an efficient mechanism to include new CoCs in the treaty facilitated by a voting option for the COP; a subsidiary body with the expertise to assess the addition of new products and CoCs and update criteria based on the latest science; binding obligations to control the production, use and trade of CoCs; transparency requirements to improve public disclosure of the chemical composition of plastics (Brander et al., Reference Brander, Senathirajah, Fernandez, Weis, Kumar, Jahnke and Wagner2024).

Regulating CoCs in all plastics is estimated to lead to significant benefits for both health and the global economy. For example, if the widely used plastic chemical bisphenol A (BPA) was eliminated from all plastics, more than 60,000 cases of childhood obesity could be prevented annually in the US and EU, with nearly USD 4 billion in health cost savings (Trasande et al., Reference Trasande, Krithivasan, Park, Obsekov and Belliveau2024). Even greater benefits would be realised if bisphenols were regulated as a class. For products of concern, we note that the initial list recommended in the Chair’s text would only result in a modest reduction in plastic pollution of 17% (Trasande et al., Reference Trasande, Krithivasan, Park, Obsekov and Belliveau2024). However, listing additional plastic products widely found in the environment (e.g., plastic bottles and lids) would assist significantly in mitigating plastic pollution while substantially reducing environmental burdens and associated societal costs. We note that essential use criteria are currently missing from the assessment of products of concern and that these should be included (Figuière et al., Reference Figuière, Borchert, Cousins and Ågerstrand2023). Additionally, Article 3 should be fully integrated with Articles 5, 6, 7 and 11 to ensure cross-compatibility and to facilitate successful implementation of the future treaty (Scientists’ Coalition for an Effective Plastics Treaty, 2025a).

Plastic product design (article 5)

The design phase is critical in ensuring safer, more sustainable and more circular plastics and plastic alternatives enter the market. Importantly, CoCs and intentionally added nano and micro-sized plastics (MNPs) should be avoided in the design and manufacture of plastic products (Syberg et al., Reference Syberg, Nielsen, Oturai, Clausen, Ramos and Hansen2022; Wagner et al., Reference Wagner, Monclus, Arp, Groh, Løseth, Muncke, Wang, Wolf and Zimmermann2024). Plastic product design (Article 5) underpins decisions regarding the use of chemicals, the essentiality of products (Article 3) and overall plastic production (Article 6). Therefore, these articles should be considered in conjunction for effective implementation and should include the following evidence-based elements: global legally binding control measures, transparency, safety, essential use and sustainability criteria, and design for circular systems. Figure 1 illustrates how evidence-based criteria are key to identifying open and adaptive lists of products groups of concern in the treaty annex.

Figure 1. Illustration of the interconnections between core elements of the decision-making process for achieving safer and more sustainable product design (Article 5) (Scientists’ Coalition for an Effective Plastics Treaty, 2025b).

Production/supply (article 6)

In 1994, the Oslo Symposium developed a working definition on sustainable consumption which has become the basis of sustainable consumption and production (SCP) discourse: “‘…the use of services and related products, which respond to basic needs and bring a better quality of life while minimizing the use of natural resources and toxic materials as well as the emissions of waste and pollutants over the life cycle of the service or product so as not to jeopardize the needs of further generations.” The United Nations Commission on Sustainable Development (UNCSD) officially adopted this working definition in 1995.

Evidence demonstrates that even if plastics production is reduced by 1–3% per year, global plastic pollution will continue to grow unless ambitious reduction targets, such as a cap on virgin plastics, are established and enforced (Bergmann et al., Reference Bergmann, Almroth, Brander, Dey, Green, Gundogdu and Walker2022; Baztan et al., Reference Baztan, Jorgensen, Almroth, Bergmann, Farrelly, Muncke and Wagner2024). The correlation between the monetary value of plastic products when they reach the end of useful life and their risk of ending up as plastic pollution has further been demonstrated (Syberg et al., Reference Syberg, Palmqvist, Khan, Strand, Vollertsen, Clausen and Hansen2020). The current dynamics of accelerating global production of single-use and short-lived products will lead to increased plastic pollution. As demonstrated by Cowger et al. (Reference Cowger, Willis, Bullock, Conlon, Emmanuel, Erdle and Wang2024), a 1% increase in plastic production leads to a 1% increase in plastic pollution. Ambitious and legally binding global plastic production reduction targets will, therefore, not only reduce the consumption of fossil and biomass feedstocks for plastic production; they are also essential for minimising the production of single-use and short-lived plastic products, increasing the longevity of products, preventing plastic pollution and, ultimately, facilitating the transition towards a more just and sustainable production and consumption of plastics. Article 6 is, therefore, key to the success of the future treaty (Scientists’ Coalition for an Effective Plastics Treaty, 2025c).

Releases and leakages (article 7)

Microplastics (including those intentionally added) and CoCs can be released or leaked into the environment, food and living organisms all along the full life cycle of plastics. Leakages and releases include emissions to air from plastics such as greenhouse gases (GHGs), plastic chemicals and plastic particulates (e.g. volatile organic compounds and MNPs). No other MEAs sufficiently address the releases, leakages and emissions of plastic pollution (Table 1).

Table 1. Do existing multilateral environmental agreements (MEAs) already address plastic releases and leakages into ecosystems? (Scientists’ Coalition for an Effective Plastics Treaty, 2025d)

To successfully prevent releases and leakages, as shown in Figure 2, Article 7 should be considered alongside other articles while ensuring upstream measures are prioritised and supported by harmonised definitions, criteria and standards, including for safety, sustainability, essential use and transparency.

Figure 2. Key links between Article 7 and other articles in the Chair’s text, including the importance of Article 7 to the treaty (Scientists’ Coalition for an Effective Plastics Treaty, 2025d).

Finance (article 11)

An effective and just financial mechanism will be crucial, not only to achieve an agreed text but also to ensure that all member states can meet their legal obligations under the treaty. Financing will be needed to support the implementation of measures across the full plastics life cycle to achieve systemic change at a global scale. It is important that financing strategies and obligations are underpinned by core environmental principles and fundamental human rights (OHCHR, 2024) to safeguard against burden shifting and ensure plastic polluters are held accountable. Outcomes from other MEAs indicate a need to mobilise new resources and to redirect and realign existing financial incentives (Barrowclough and Birkbeck, Reference Barrowclough and Birkbeck2022; UNEP FI, 2023).

Our review of the Chair’s text also identified potential risks in Article 11 to the effectiveness of the treaty. These include overemphasising the efficacy of waste management and missing connections between finance and other measures in the treaty text. These omissions are key because they fail to incentivise the most effective responses, i.e., prioritising supply side measures that affectively address plastic leakage, releases and emissions. Instead, the draft text problematically prioritises downstream financial investments in techno-economic lock-ins which lack sufficient safety and sustainability criteria, standards, monitoring and reporting requirements. Finally, the prospect of plastic credits risks repeating past false solutions. Evidence from carbon markets shows that credits often fail to deliver concrete environmental or social benefits (Moon et al., Reference Moon, Tangri, Bonisoli-Alquati, Ralston, Bergmann, Syberg, Olsen, Wang, Castillo, Colombini and Alegado2025). There is an opportunity for the treaty to overcome these challenges with a financial mechanism that addresses overproduction and incentivises safer, more sustainable, accessible and cost-effective upstream solutions (Scientists’ Coalition for an Effective Plastics Treaty, 2025a).

Human health (article 19)

Health is a fundamental human right (UNGA, 1948, 2022), which can only be upheld by a global plastics treaty that addresses adverse human health effects that occur at all stages of the full life cycle of plastics. A standalone article on health is supported by many member states and health experts. A strong treaty will centre the protection of health in the preamble and the objective, within a full life cycle approach to addressing plastic pollution and will integrate health across relevant articles. Health concerns underpin the need for legally binding global targets to reduce plastic production (Article 3, 6), to reduce the number of chemicals used in plastics and to eliminate hazardous substances, ideally through group-based approaches (Articles 3 and 5). This can be supported by establishing harmonised safety criteria for plastics and their alternatives, including through safe product design (Article 5) and by ensuring mandatory transparency and traceability throughout the life cycle of plastics (Articles 3, 4, 5, 6, 8, 9, 17, 18). Sectoral exemptions, including for the health sector, do not protect human health and will hinder progress in addressing plastic pollution. Providing mechanisms to support and integrate emerging science is critical to ensuring the treaty is future- proofed to protect human health (Articles 3 and Annex, 5, 6,19, 20, 24). This can be supported by a subsidiary science body that mitigates conflicts of interest and includes health scientists and practitioners (Scientists’ Coalition for an Effective Plastics Treaty, 2025c).

Science-policy Interface

Science-policy interfaces (SPIs) enable exchange and integration of the best available science into policymaking (Allen et al., Reference Allan, Borthakur, Kinninburgh, Petersmann, Balayannis, Barry and Vadrot2025). They are crucial for fully informed treaty negotiations and the operationalisation and implementation of the treaty provisions (Rucevska et al., Reference Rucevska, Mafuta, Hinkle, Macmillan-Lawler, Skripnikova, Sevaldsen and Urho2023). A dedicated SPI as a subsidiary body of the future treaty will be important, as will regular opportunities for independent expert input in the form of regular invitations to submit information to the COP, and the formation of expert or working groups and/or science advisory panels. An SPI with robust participatory, transparency and inclusivity policies could future-proof, streamline and strengthen the treaty. An effective SPI will guide the development of globally harmonised criteria, standards, assessment, monitoring and reporting (Spring et al., Reference Spring, Schröder, Popovici, O’Meara, Corsi, Aliani and Sakellariadou2025). Horizon scanning will identify emerging issues and information gaps and estimate and prevent impacts and avoidable costs, including costs of inaction and regrettable technologies, systems, alternatives and substitutes. An effective SPI will also have the capacity to interpret the complex science of plastics for non-scientists and establish open access platforms to ensure equitable availability of the best available science. Well-designed SPIs ensure policy remains scientifically up to date and valid in the face of environmental, economic, technological and social dynamics. Importantly, SPIs with conflict-of-interest mitigation policies and processes will be essential to protect future decision making from vested interests and enhance public trust (Scientists’ Coalition for an Effective Plastics Treaty, 2024).