I wonder how much time they require in a natural environment. I left a small chunk of PLA outside for weeks and saw literally no signs of biodegrading. It might be better than regular plastic but its no banana peal.
No, PLA won't just rot. In industrial composting environments it will be completely gone. In cool dry environments it will last for a long long time.
They use PLA in dissolvable stitches (one of a few options) and those thin fibers are dissolved within a few days to a few months. It depends much on environment.
