Bio-plastics safety Mark

Another Dyson candidate
POTATO PLASTIChttps://www.jamesdysonaward.org/en-AU/2018/project/potato-plastic/

The idea is clear and very needed, however, I would argue much more safety is essential.

I think that 2 months is too quickly, we jeopardize yourself to eat with contaminated cutlery (don't expect fast and on time shop delivery and consumption  ~gangrene).   More studies needed my personal opinion 2-4 years before the beginning of the degradation (ocean life actually can consume even current plastic (before 80 years), but it's still an issue).
So a simple indicator to show it started to rot is needed as a standard:
My proposals are to have standardized thin layer which will work as a fuse (of to add stimulators to promote visual results):

1 A thin layer with a catalysator drop, 2 Just thin 3  Mesh-like structure with large surface exposure.