I think for plastics the right answer is standardization. I know that's not people want to hear, but I don't think there is any way around it.
1. Ban all single use plastics that can be replaced somewhat economically with biodegradable materials (with a small price increase, maybe 2-5-10%).
2. Standardize plastic container compositions, shapes and sizes in a huge ISO catalog. EVERY product a company makes/uses has to be from this catalog. Companies can add another category one by going through the standardization process. Marketing can be done by applying biodegradable materials to the exterior.
Basically have a few material compositions:
- high strength/heavy
- medium strength/medium weight
- reduced strength/light
Have a standardized set of sizes:
- 100ml (and US equivalent)
- 250ml
- 330ml
- 500ml
...
Plus a standardized set of shapes for each size.
At the end of the day you'd get:
3 x number of sizes (probably 40-50 sizes?) x number of shapes (probably 10-15 shapes per size?) = 1200 - 2250 categories. And I'm being generous here, I think we should probably keep this total number under 500, ideally under 100, but I don't think such a low number is feasible.
Then charge a deposit for each plastic container and upon container return give this deposit back.
Same thing for glass, actually.
This would make plastic containers reusable, even across brands, and would probably reduce our plastic waste by orders of magnitude.
Heck, the same thing could probably be done for plastic bags.
However, this plan would also reduce plastic consumption (and production, so $$$) by orders of magnitude, so I don't expect it to ever pass a solid lobbying plan.