Biodegradability of Plastics in the Open Environment

The report explores biodegradable plastics (BDPs) and their potential in mitigating plastic pollution. It highlights the need for a cautious, evidence-based approach, emphasizing clear criteria, rigorous testing, and targeted applications to maximize environmental benefits.

The report defines biodegradation as the microbial conversion of organic plastic components into carbon dioxide, methane, biomass, and mineral salts. This process is influenced by material properties and environmental conditions. Open environments, such as soil, freshwater, and marine ecosystems, pose unique challenges due to their uncontrolled nature, leading to variable biodegradation outcomes.

Plastic pollution continues to rise, with substantial ecological and environmental repercussions. While BDPs are often viewed as a solution, their efficacy is context-dependent. Most BDPs degrade only under specific conditions, such as high temperatures in industrial composting facilities, which are not typical in natural settings. This emphasizes the need for a systematic evaluation of their environmental benefits and limitations.

The report advocates treating biodegradability as a system property, factoring in both material characteristics and environmental conditions. It recommends restricting BDP use to cases where reduction, reuse, and recycling are unfeasible. Suitable applications include agricultural mulch films, fishing gear, and fireworks, where recovery is impractical. However, BDPs are not advisable for single-use packaging due to risks of littering and environmental accumulation. Rigorous testing and certification protocols are crucial to simulate real-world conditions, ensuring BDPs fully biodegrade without harmful residues. Developing a catalog of biodegradation rates across diverse environments is also recommended.

Clear communication and standardized labeling are essential to address widespread consumer confusion about biodegradable, bio-based, and compostable plastics. Labels should specify the intended environment, conditions for biodegradation, and disposal guidelines to prevent mismanagement. This approach aims to mitigate the risks of greenwashing and ensure informed decision-making.

Challenges include a lack of harmonized standards, definitions, and testing methods, which complicate policy development and market adoption. The report aligns with the European Strategy for Plastics in a Circular Economy and the European Green Deal, prioritizing reduction, reuse, and recycling while advocating research into sustainable plastic alternatives and enhanced waste management systems.

In conclusion, BDPs can play a role in reducing plastic pollution but require careful, targeted application supported by robust scientific evidence. Policies should focus on areas where BDPs offer clear advantages and avoid undermining existing recycling and waste management efforts.