Polymer degradation in compost (IMAGE) University of California - Berkeley Caption A modified plastic (left) breaks down after just three days in standard compost (right) and entirely after two weeks. Credit Christopher DelRe, UC Berkeley Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.