So I got into a little argument with some friends on just how environmentally friendly PLA is.
I am coming from the angle that PLA is much better than plastic, as it is biodegradable, so while humans are still looking for a perfect plastic replacement, we can use PLA first for everyday needs, like straws and plastic bags. Not littering and correctly collect PLA waste for composting is important when it comes to being environmentally friendly, but there’s just no way to ensure people wouldn’t let the stuff go into the ocean, and I’d rather have PLA in the ocean than petroleum plastic.
My friends are saying that PLA being biodegradable is a myth, and Monsanto has gotten into all research papers claiming PLA is biodegradable. They say instead of being biodegradable, PLA at most breaks down into tiny plastic chunks that will end up in the marine life.
I went through some recent papers (published after 2017), and most of them say PLA can be degraded through hydrolysis. Water will break the ester bond and you will end up with the left over carbonyl group, when then can be metabolized by bacteria and the end product would be CO₂.
Now, perhaps this process is slow. Not hundred-thousands of years slow like regular plastic, but 5 to 10 years slow in the ocean. It can be sped up with heat or being in a compost, but I’m mainly concerned about the stuff in the ocean. If it breaks up into tiny pieces and hasn’t yet been metabolized by bacteria, I can see how it could get ingested by marine animals.
So is PLA really biodegradable? Other than just saying no plastic, what’s a good alternative so that we don’t gunk up the ocean?
I mean all the papers I see seem positive…