I seem to recall that certain types of plastic that are regarded as biodegradable will only biodegrade in particular conditions, such as with heat or UV exposur

I seem to recall that certain types of plastic that are regarded as biodegradable will only biodegrade in particular conditions, such as with heat or UV exposure. I've no citation for this, it's only a vague memory from something I saw years ago. (YMMV, it's worth what you paid for it, all that kind of thing.)