‘Compostable’ Plastics and Ugly Truths

With the rise of consumer awareness about environmental issues comes a corresponding demand for more environmentally friendly products, which on the surface is a great thing to hear. I want people to be thinking about where the products they use come from and choosing more ethical options. The problem, though, is that many consumers are seduced by greenwashing and labeling advertising something that simply isn’t true, and they don’t realise that they’re not actually making the best choice for the environment simply by buying something that claims to be eco-friendly. Self-education and research are still required for people who want to make a difference.

I see a classic example of this with ‘compostable’ plastics, which have burst onto the scene as an alternative to conventional plastic in the last few years. They seem like such an obvious replacement; we can stop using petrochemicals to make products that will last for thousands of years and may or may not be recycled depending on how consumers handle them, we can reduce dangerous leachates and the use of toxins in production, and we can use our formerly disposable dinnerware to grow plants. How could this possibly go wrong?

Well, in a couple of ways, as it turns out. Compostable plastic is made in a lot of different ways but the most common form is made from corn, a crop that happens to be extremely high maintenance, requiring a lot of land, water, and resources for production. Developing yet another product made from corn may not be the best move, despite the claims of environmental benefits offered by compostable plastics. While corn may be renewable, it is not necessarily environmentally friendly, and let’s not forget the petrochemicals involved in the production not just of corn, but of the finished plastic products as well; you’re still using nonrenewable and sometimes toxic resources, just at a remove from the end product.

And how compostable is that plastic, really? When you hear compostable, you probably think of material that would break down easily in a kitchen or backyard compost, depending on the setup you are more familiar with. Have you ever tried composting a plastic cup or other supposedly compostable plastics, or known anyone who has? If you have, you know that compostable plastics, with the recent exception of Lays’ attempt at an eco-friendly chip packaging, don’t break down in a regular compost pile. Instead, they hang out being plasticy. For quite some time. Like, a very long time.

That’s because they need high heat to break down, the kind of heat you get at industrial composters. If you subscribe to a compost service that actually maintains industrial compost, sure, your compostable plastics will get broken down—but even then, not necessarily. It turns out that compostable plastic can also disrupt the chemistry of a compost pile, which is why some firms prefer to break it down separately in its own facilities so it doesn’t interfere with the delicate balance of elements in regular compost. And others send it straight to the dump.

In a sad way, one of the best places for compostable plastic is in fact the landfill, where it can actually act as a great carbon sequestration sink, because corn certainly does one thing really well: It traps carbon. If you bury compostable plastic under the earth, that means it’s not releasing carbon, and that in turn can help control greenhouse gases. It will eventually break down in the landfill over time, more quickly than conventional plastics, but meanwhile, it can serve an unexpected environmental function in doing exactly what it’s not designed to do: hang out in the earth and go nowhere.

Using compostable materials to reduce waste seems like an obvious way to help the environment, but it’s not as simple as it appears, like so many ‘green’ choices. Behind every new supposedly environmentally-friendly product typically lies another, more complex, story that needs to be ferreted out and addressed before shelling out for those products. Don’t be seduced by green packaging and friendly claims, artful brown paper and whimsical decorations suggesting that you’re helping the planet. Find out about the science behind this products, and whether they’re all they’re cracked up to be, before you go getting too excited.

The information isn’t that hard to find; publications like Scientific American, for example, regularly test and discuss a variety of options to see if they really match the claims made on their packaging and by their creators. Environmental organisations also audit such products to see if they’re as good as they say they are, and discuss potential alternatives and other solutions for people who would prefer more aggressively environmentally-friendly options. People who actually work in the trenches—like farmers working with compost, for example—can also provide insight into how these products might or might not work, and whether they are indeed a good buy.

Given that many of these products are more expensive than their conventional counterparts, it’s well worth evaluating before you buy to determine if you’re just being exploited with a green label to guilt you into buying so you’ll be viewed as a ‘good consumer,’ or whether a product really is as awesome as it sounds like it is. If it is, the higher cost might well be worth it, because it could reflect more fastidious production practices as well as the expense of research and development. If the product isn’t that much better than a conventional one, though, what you’re really paying for is green cachet, and is that really worth it?