Standards Development

Scope

This document specifies a laboratory-level test method to determine the combined aerobic and anaerobic biodegradation rate and extent of plastic materials when settled on sandy sediments at the interface of the seabed and seawater. This test method can also be applied to other materials. Biodegradability shall be determined by the combined measurement of carbon dioxide (CO2) and methane (CH4) evolved from plastic materials exposed to sediment and seawater collected from the sublittoral zone under laboratory conditions. The test method simulates the sediment-covered state of plastics introduced into the sublittoral zone under laboratory conditions. The conditions described in this standard do not necessarily represent the optimal environmental conditions required for maximum biodegradation in marine environments.

Purpose

This proposed standard addresses the urgent global need for reliable and harmonized test methods to assess the combined biodegradability of plastic materials in marine environments, especially under sediment interface conditions. With increasing awareness of the environmental impacts of plastics and microplastics, international policy frameworks such as the European Green Deal and Circular Economy Action Plan have emphasized the importance of reducing marine pollution and fostering sustainable materials. In particular, the European Union has committed to promoting biodegradable plastics only when they demonstrate clear environmental benefits and compliance with standard biodegradation conditions. The European Bioplastics Association (EUBP) has explicitly advocated for the establishment of standardized marine biodegradation test methods, noting the current lack of methodologies that reflect real marine conditions (i.e., sediment and seawater interface with both aerobic and anaerobic microbial activities). The proposed ISO standard is designed to fill this technical gap by providing a robust laboratory-scale method that simultaneously assesses aerobic and anaerobic biodegradation using gas evolution analysis (CO2 and CH4). This method builds upon existing standards such as ISO 19679 and ISO 22404 but expands their scope by incorporating combined aerobic and anaerobic processes, making it more representative of marine sediment zones. Furthermore, the method aligns with broader international efforts to develop materials that truly degrade in marine environments without leaving harmful residues. By establishing this test standard, the ISO community can support regulatory frameworks, guide industry innovation, and ensure transparent labeling of marine-biodegradable plastic products. (Please use this field or attach an annex)

European Commission. A European Green Deal: Striving to be the first climate-neutral continent. COM (2019) 640 final. https://eur-lex.eu.europa.eu/legal-content/EN/TXT/?uri=CELEX:52019DC0640 European Commission. Circular Economy Action Plan: For a cleaner and more competitive Europe. COM(2020) 98 final. https://ec.europa.eu/environment/strategy/circular-economy-action-plan_en European Bioplastics (EUBP). Marine biodegradability of plastics – a standardization need. EUBP Position Paper, 2022. https://www.european-bioplastics.org