Is PLA Compostable Or Biodegradable?

Polylactic acid (PLA) is a material that has been around for decades. Until recently, no major producer of PLA existed until they were funded by mega-corporations to enter the marketplace as a replacement for synthetic plastic. BioSphere Plastic often receives inquiries about whether PLA is biodegradable. While the answer is not straightforward, we have decided to create a post to explain what PLA really does and provide further reading for those interested.

PLA is not biodegradable; it is degradable.

Enzymes that hydrolyze PLA are not commonly found in the environment, except on very rare occasions.

Proteinase K catalyzes the hydrolytic degradation of PLA.

Williams in 1981 and Tsuji and Miyauchi in 2001 asked the same question: "Is PLA biodegradable?" They have written white papers on the subject and are featured in the book Biomaterials Science: An Introduction to Materials in Medicine. In the book and at the European Society for Biomaterials conference, it was discussed that PLA degradation is controlled by hydrolysis and this hydrolysis is independent of all biological agents.

So while many people believe PLA to be biodegradable, it simply is not. PLA is degradable and should be considered as such. In the Biomaterials Science book, the authors actually state that the occurrence of Proteinase K hydrolyzing PLA is so rare that it is not worth further discussion.

We hope this clarifies the question of whether PLA is biodegradable. We will continue to work towards the best solutions for your green plastic and biodegradable needs.