I wonder how they break down outside of a compost environment? My company uses "compostable" plastics which feel like normal plastic. I've used the same compostable clear plastic cup for months on end and it isn't showing any signs of degradation. I suspect it would break down in a proper compost pile(high temps and such) but outside of that environment it seems as durable as traditional plastic. Hopefully in an environment like the ocean it would be susceptible to bacteria and fungi but I wonder if that is sufficient.
Our local composting company explicitly excludes compostable utensils and food containers. Compostable doesn't mean biodegradable. For example, compostable cardboard food containers may be coated with perfluoro compounds to prevent liquids from soaking into the cardboard. These don't biodegrade.
Yes, that also goes for paper cups with the wax coating. They don't biodegrade and they aren't recyclable because of the wax. That's probably the same coating you mention. It seems that this solution just replaces one problematic material with another when it coats something that would otherwise be biodegradable.
Yes, lots of "biodegradable" products do have PFAs. Including most of the paper straws that are supposedly better than plastic ones. That's a result of corporate lobbying right there.
The point of the products I mentioned is that they don't contain PFAs. They are starch and cellulose. Cellulose just so happens to look and behave an awful lot like plastic. If you've ever seen those novelty see-through rolling papers, they're the same thing but without the starch. You're not smoking PFAs with them.
The process is expensive. It's hard to convince people the extra costs are actually worth it in the end. Hopefully they keep working on the products and discover some manufacturing efficiencies. But it is like competing real fruit beverages against big-name colas - it's a tough battle to win.
My understanding is that they are starch and cellulose, so I'd expect them to eventually completely degrade like any other plant material. I'm not an expert, but that seems to be the point of products made with it.
Our liquor store (LCBO) used to have bags made from the same stuff. When our provincial premiere got everyone to charge 5c for each plastic bag, they just stopped using it entirely and went to paper bags. I liked those original compostable/recyclable ones because they were less stretchy and therefore less likely to break than normal plastic grocery bags, and way easier to carry because of the handles.
But the same reasoning applied - it was more expensive than paper bags, so that's all they use there now, too.
I've been using a wooden desk for decades and it's not showing any signs of degradation either, yet wood waste is not an environmental problem. Compostable plastics degrade very slowly compared to other compostable materials. Your normal garden compost heap probably doesn't break them down in a year. But they do decompose much faster than normal plastic, they don't stick around in the environment for millennia.
A well protected / maintained desk versus the usual stuff thrown into a rotting heap of other delicious-to-bugs and vulnerable-to-water items isn't a realistic comparison, so I don't get the gyst of this response.
Besides, I was talking about a set of products that are made from starch and cellulose. They'll break down real fast with the rest of the compost. Faster than your desk that also would degrade and get eaten up under those same conditions.
