Biodiversity and chemical regulation: Status quo, data gaps, and recommendations for future action

Global biodiversity is declining, driven by multiple, interacting pressures including the 5 most prominent of resource use, habitat loss, invasive species, climate change, and chemical pollution. While chemical exposure is recognised as a potential driver of biodiversity loss, quantitative links and its relative impact compared to other stressors remains poorly understood. The European Union (EU) has intensified efforts to reduce pollution and restore biodiversity through strategic frameworks such as the Biodiversity Strategy, Farm to Fork Strategy, Zero Pollution Action Plan, and Chemical Strategy for Sustainability. Key chemicals regulations like REACH and the Plant Protection Products Regulation aim to protect ecosystems, however, due to the complexity of ecosystems and the range of impacting stressors it is difficult to measure their direct impact on maintaining or improving biodiversity objectives. This review, conducted by a multidisciplinary Task Force brought together by ECETOC, evaluates the current state of biodiversity research efforts and its integration within EU chemical regulation. We examined EU legislation, strategy documents, EU-funded research, and peer-reviewed literature to identify biodiversity definitions, metrics, and methodologies, and to highlight gaps in linking chemical exposure to biodiversity outcomes. Findings indicate that: current chemical regulations reference biodiversity mainly qualitatively, biodiversity research often lacks a focus on chemical impacts, and research outcomes are not clearly linked to regulatory frameworks. The relationship between biodiversity and chemical impacts is further complicated by diverse definitions and metrics of biodiversity in the academic literature, with limited consistency across biomes and minimal alignment with chemical risk assessment practices. To strengthen biodiversity considerations in chemical regulation, we recommend: developing operational definitions of biodiversity applicable across regulatory contexts; standardising metrics and indicators; establishing a centralised data platform for biodiversity research; and leveraging existing data, methodologies, tools and new technologies (e.g. machine learning). Bridging knowledge gaps between policy objectives and available approaches, whilst aligning biodiversity considerations across both chemical regulation and other regulations which can impact biodiversity such as habitat loss, will promote coherence and cooperation. Continued multistakeholder engagement and alignment is critical in achieving these recommendations.