Good example of greenwashing: Corn-based plastics

Here's an email from Rebecca:

Hi Enviromoms! OK I have been thinking about the fact that putting food in the landfills is bad and came up with another question. What about all the new corn based products out there that are suppose to be good because the are biodegradable? I have even found diapers that are corn based (for vacations) and use corn based garbage bags. Is this really helping though?

Corn-based plastics are still disposable products, which is pretty much the main reason neither Renee nor I like them. Here are some other reasons:

• Creating corn-based plastic (PLA) is energy-intensive. Farming corn itself is pretty intense, and most corn-based plastics are grown from genetically-modified, non-organic corn. Add in the herbicides, run-off, erosion of topsoil, emissions from farming equipment, transport and manufacturing of the product -- ugh.

• It's crazy to use good farm land to grow food used in DISPOSABLE PRODUCTS. How about if we just grow good food, like edible, organic vegetables?

• The whole schtick behind corn-based plastics is that they are biodegradable. But where? Only in industrial composting facilities (home systems don't get hot enough), and according to a July 2008 article in the Christian Science Monitor, there are only 113 such facilities in the US. We don't have one in Portland. Even Seattle, which has one for its curbside food composting, won't accept corn-based plastics in their residential pick-up program because they biodegrade at varying rates. Plus, as PLA7 plastics degrade, they don't actually add any nutrients to the compost like food or yard debris do.

• The plastic takes as long as 1000 years to biodegrade in a landfill because it doesn't receive the air and water necessary to break down. And as it's breaking down, it's releasing methane (just like food).

• PLA plastics cannot be recycled. They are a huge contaminant in the recycling process.

Renee and I learned a lot about the evils of corn-based plastics in our Master Recycler course, and there's plenty of info out there backing up all of these points. Manufacturers of corn-based plastics want you to think you are being green by purchasing their products. But it's all disposable stuff, which is inherently NOT GREEN. Are they greener than petroleum-based plastics? Once you factor in all of the stuff mentioned above, I really don't know. Maybe. Petroleum comes with it's own set of nasty environmental issues. And war!

But the bottom line is that we should all be trying to lessen our consumption of disposable products. It's hard, I know. Sometimes I pick up a plastic clamshell container at the grocery store, because it contains something delicious that I MUST EAT. I get it home and it's a PLA container, which I have to throw in the garbage, which makes me crazy. Typically we can recycle non-PLA plastics at round-ups here in Portland. But again, the goal is to reduce, reuse, recycle in that order.

So let's take dog poop (please). Best way to dispose of it (at least in Portland) is in a plastic bag in your garbage. You know those corn-based doggie doo plastic bags you can buy? A lot of energy went in to manufacturing those bags, only to have you throw them out. It's far better to reuse an existing plastic bag, like from a newspaper, and give it a second life. Those newspaper bags are petroleum-based, obviously not good either, but they are already being produced for one use. Reuse it and extend its lifetime. Don't get the paper? Come to my house and take my newspaper bags, please! (On my to-do list for months has been to alert my dog-owning neighbors that they can gladly take my newspaper bags.)

If you have the choice between buying a corn-based diaper or a petroleum-based diaper, I'm not really convinced there's any difference. They both suck, and both are headed to the landfill, just like the dog poop bags. (Full disclosure: I used Huggies on both of my kids. Were I to do it all over again I like to think I'd try cloth.)

And garbage bags? Try using recycled-content plastic garbage bags, like from Seventh Generation.

Sorry to be so preachy. This is one of those topics that gets me all worked up, though not in the fun way like watching Robert Downey, Jr. in Iron Man. Bottom line: try to decrease your consumption of disposable plastics, but when you have to, choose recycled-content products first. Hope this helps. We're happy to try to answer questions about disposable alternatives and plastics (though we're certainly not plastics experts). And if you have a constructive argument in favor of corn-based plastics, let's hear it!