This is why I have developed an aversion towards any plastics containing halogens: chlorinated like PVC, materials with brominated flame retardants, or worse: f

This is why I have developed an aversion towards any plastics containing halogens: chlorinated like PVC, materials with brominated flame retardants, or worse: fluorinated compounds like PFAS. Burn those, and a whole slew of nasties is produced. Common plastics like PE, PP & such at least in theory can burn cleanly. If so: make 'm bio-based, maybe a few downcycling steps, followed by burning, maybe isn't too bad overall. I have a bigger problem with discarded plastic (and related: microplastics) getting everywhere in our environment. That's an overlapping but different problem. Plastics have their uses & advantages, but we really should be more critical about where they're needed & where not.