We were eating at Stone Hearth Pizza tonight, and I noticed a box on the menu that said their takeout containers were made of corn plastic rather than regular plastic or styrofoam. This started a debate about whether corn plastic was actually any better than regular plastic. Okay, maybe not as much a debate as Sharon telling me that I was just being contrarian. But the Ask Umbra column on Grist talked about this issue just last week, so it was at the top of my mind. Smithsonian magazine had a good article on the subject a few years ago, too.
I think corn plastic is just greenwashing, because, while it can technically be composted, only a tiny tiny percentage of it actually will be. Most of it will end up in landfills, where, without any oxygen, it won’t break down any more than other trash.
Not only that, but it won’t break down in my worm bin or in your backyard compost, either. It needs temperatures of 150 degrees Fahrenheit, which is only reached at large commercial composting facilities.
Here in Cambridge, we can take it to the Department of Public Works or Whole Foods for composting, but I doubt most towns have such options. So even most of the people who would compost it, can’t. It’s just misleading.
And while #7 plastics (the catchall “other” category that this falls into) are accepted by Cambridge for recycling, corn plastic in particular may not actually get recycled, because there’s not a large market for it. For that reason, most towns don’t even accept it in recycling bins.
Of course, we all agree that petroleum is not a good option, but neither is industrial corn farming. And at least regular plastic can reliably be recycled. So I think until municipal composting becomes commonplace, corn plastic just seems pointless.