Understanding biodegradation of chemicals in the environment is becoming increasingly important. There are several assays available to determine if a compound is biodegradable. Cheng (Cheng 2012) provided data and references for a set of 1,604 compounds that have undergone either the Japanese MITI (14 day) or the OECD 301C (28 day). After removing all metal containing compounds and retaining only a single stereoisomer or tautomer of structurally redundant entries, 1,581 compounds remained.