BACKGROUND-AIM:
As the EU prepares revision of the Single-Use Plastics (SUP) Directive, global governance is shifting: COP11 adopted the decision on Article 18 FCTC, clarifying Parties’ environmental obligations, while negotiations of a UN Plastics Treaty continue. These developments raise questions of coherence across EU law, international environmental law and the FCTC. This study examines: the state of play of the SUP revision; key regulatory challenges; interactions with the Tobacco Products Directive (TPD), FCTC Article 18, and the emerging Plastics Treaty.

METHODS:
A comparative analysis will be conducted of the SUP Directive, the TPD, draft UN Plastics Treaty text, and the FCTC COP11 Article 18 decision. This includes: an assessment of regulatory gaps, risks of Treaty interaction under the Vienna Convention; scientific evidence on filter toxicity, chemical leachates and environmental persistence; examination of the growing market of biodegradable/plastic-free filters and their associated misleading claims; analysis of Extended Producer Responsibility schemes and their potential breaches of FCTC Article 5.3.

RESULTS:
The SUP Directive faces several problems: its scope is limited to plastic filters, enabling the rise of equally harmful “biodegradable” alternatives; its EPR provisions allow tobacco-industry involvement that conflicts with FCTC Article 5.3; and it insufficiently covers waste from new nicotine products. The Tobacco Products Directive (TPD) could provide a legal path as Article 7 allows restrictions on product features that increase attractiveness, and cellulose acetate filters clearly facilitate deeper inhalation and smoother smoking. At the same time, the UN Plastics Treaty presents a separate risk: current drafts prioritise trade protections and provide weak links to health treaties, meaning that without explicit alignment, future plastics rules could undermine stronger FCTC-based measures such as filter bans, independent EPR and hazardous-waste classification.

CONCLUSIONS:
The SUP revision is critical to align EU policy with global environmental and health frameworks. A material-neutral filter ban would reflect scientific evidence, prevent regulatory loopholes, and support implementation of COP11 FCTC Article 18. Should EPR remain in place, they must exclude industry involvement to comply Article 5.3, Article 13 and avoid greenwashing. Explicit alignment with the TPD, the FCTC (article 2.1, 5.3, 13 and 18), and the emerging UN Plastics Treaty is essential to ensure coherent, prevention-focused regulation of tobacco product waste. Such alignment would produce high-impact benefits for both public health and the environment.