Ultimate aerobic biodegradability of a plastic product in soil. This method is based on carbon dioxide evolution or oxygen demand as measured in a closed respirometer as the sole product of biodegradation. The carbon dioxide is measured as dissolved inorganic carbon in the liquid phase and as carbon dioxide gas in the headspace. The participant will execute the project using the CO2 collection method since mineralization is the most robust evidence of biodegradation. ISO 17556 ASTM D5988