End of Life of Materials: Biodegradability and Compostability Assessment

This case study examines the biodegradability and compostability of packaging materials, particularly focusing on their end-of-life scenarios. It explores various aspects, including managed waste processing, in-situ biodegradation in natural environments (soil, freshwater, and marine conditions), and industrial composting processes. The research aims to establish protocols for testing materials based on biodegradability, disintegration, and eco-toxicity to ensure they meet rigorous environmental standards.

Biodegradability assessments follow ISO 14855-1 guidelines, determining whether materials degrade at least 90% within six months in controlled composting conditions. Disintegration tests, based on ISO 16929, evaluate whether less than 10% of a material remains undisintegrated after 12 weeks of composting. Additionally, eco-toxicity assessments, guided by OECD 208 standards, analyze the impact of composted materials on plant germination and growth. To ensure safety, these tests require the resulting compost to have no toxic effects on barley and cress seeds, with a growth index of at least 90%.

The study highlights the role of certification schemes, such as TÜV Austria and DIN CERTCO, which validate the compostability of materials under industrial and home composting conditions. Industrial composting involves high temperatures (approximately 58°C), while home composting requires a lower temperature and longer time frame (up to 12 months) for achieving similar outcomes.

The findings underline the potential of biodegradable materials in reducing environmental pollution caused by conventional plastics, which persist in ecosystems as micro- and nanoparticles, accumulating toxins and infiltrating the food chain. However, the research emphasizes that effective biodegradation depends significantly on the environment in which materials are discarded.

The conclusions stress the need for rigorous testing and certification for labeling materials as compostable or biodegradable. Additionally, ongoing efforts are required to validate these behaviors in diverse environments, including soil, water, and marine ecosystems. The study provides a foundation for promoting sustainable materials while mitigating the ecological footprint of packaging waste.