ACS Sustainable Chemistry & Engineering

Biodegradable materials are used to make compostable products that are expected to be collected and recovered in specialist waste treatment plants. The appropriate targeting of their distribution and marketing can bring systemic benefits by enabling improved organic recycling. At the same time, there is growing interest in knowing the environmental impacts of solid waste that has leaked into the environment, including the littering of compostable packaging waste. International Standard (ISO) test methods have been developed to determine the “ultimate” biodegradation of plastic materials exposed to environmental matrices (e.g., soil, marine sediments). High levels of conversion to CO2, comparable to those achieved by generally recognized as biodegradable (GRAB) substances, indicate that the plastic is intrinsically biodegradable. The term “intrinsic” refers to an inherent quality dependent on the chemical composition and structure of the material, prior to consideration of any “extrinsic” properties. Residence time, which has an effect on biota’s exposure to the litter, is a relevant factor in the assessment of ecological risk of littering. Residence time is affected by the litter’s persistence, which in part is determined by the litter’s intrinsic biodegradability. Thus, the intrinsic biodegradability is key information in this assessment. The need for a comprehensive approach based on the assessment of the ecological risk of solid waste littering, including an assessment of biodegradability, is established.

Intrinsic Biodegradability of Plastics and Ecological Risk in the Case of Leakage