Fact: Not necessarily. Whether a polymer is biodegradable depends ultimately on its structure, rather than how it is produced. While most Class A and Class B bio-based polymers happen to be biodegradable, only a few Class C polymers (e.g. PBS and PBAT) are. In other words, PLA, even if chemically synthesized, would still be biodegradable; conversely, polyethylene, bio-based or oil-based, is always nonbiodegradable.