The Green Plate: The Dark Side of Bioplastic

ColumnWhy bio-plastics aren’t as green as you think.

When was the last time you attended an event where food and drink was sold in disposable vessels?

If you’re an EcoSalon reader, it’s likely that after consuming your food or beverage you examined the container carefully to see if it was made from corn (or another plant product). And if it was, you probably then looked around for a compost bin to throw it in. Did you find one?

I’m guessing you didn’t and, left without much choice, you threw it in the garbage, maybe feeling a little uneasy, but consoling yourself with the thought that at least the container wasn’t made from petroleum, and it would break down. Right?


There are two problematic factors in potato, corn, and other plant-based plastics, which are often called “bioplastics.”

The first is disposal. Because many municipalities (even large cities like New York) don’t offer curbside composting, there’s an intention gap. Even the ones that do offer such a feature may offer residential, and not commercial composting, which means you’d have to bring your cup home with you to compost it. Realistically, how many people are going to do that?

Then there’s the labeling. Some compostable packaging and containers are not clearly labeled and can be indistinguishable from petroleum-based containers. Only highly motivated consumers will go that extra mile to find out, especially if there’s only one bin in which to toss your waste.

Some compostable ware may actually be worse for the environment than petroleum-based ware. Or at best, it might just be feel-good gesture or a marketing opportunity for companies or restaurants using it.

Still, plant-based plastic is a net win, right?

Probably not.

Consider net energy use. Lifecycle studies show that, as far as energy or water use goes, the production of petroleum-based plastics may actually be less taxing on the environment than the production of some plant-based plastics. This is partially because agriculture is fossil fuel and water intensive, and most plant-based plastics are produced using agricultural processes, including resource-intensive, soil-depleting mono-culturing.

There’s the issue of breakdown and associated greenhouse gases, too. Theoretically, bio plastics will break down faster than petroleum based plastics, but in a landfill, almost nothing breaks down due to lack of oxygen. And if the bio plastics do break down, that’s not necessarily a good thing since they can emit methane, a greenhouse gas 23 times stronger than C02.

Is anyone getting it right?

I spoke to Helene York, Director of Strategic Initiatives for Bon Appétit Management Company,  a food service company that strives to lessen its impact on the environment through its business practices.

Among other initiatives, the company instituted the Low Carbon Diet. In addition to reducing meat and cheese consumption, reducing the use of airfreight, and other company wide actions, the Low Carbon Diet addresses the problem of waste – both food and non-food waste.

I asked York if plant-based plastics or petroleum were the better choice.

“What’s the environmental problem we’re trying to solve?” she asked.

Then she went on to outline the complicating considerations that make this question of “plant based?” or “petroleum based?” such a dilemma.

According to York, “If the problem is climate change, ocean acidification (which is related to climate change), total energy use, soil erosion, water use, or the decline of water tables in the Midwest, then most plant-based resins aren’t a better choice than most plastics.” Because they rely on agriculture.

“If the problem is keeping plastics out of the landfill, this isn’t an environmental problem. It’s a municipal finance problem. Plastics in a modern landfill are inert and they don’t leach. They don’t do anything in fact, while plant-based products have the potential to breakdown and generate methane.”

And then York gets to the heart of the question for The Green Plate:

“Do we really want to use land for growing commodity crops intended for industrial uses, whether they are for animal feed or to satisfy our convenience needs? Just because something is made with a natural or renewable ingredient,” she says, “doesn’t mean it’s a better product than something made from a durable ‘recyclable’ product like PET.”

In the end, the smartest thing is to reduce the number of disposables used entirely, which is what Bon Appétit is striving for in its daily operations.

You can do it, too. When you’re heading out of the house, why not grab a drinking vessel, or a mason jar (if you’re a hipster), and even a lightweight container? You could even invest in some bamboo flatware.

After all, you never know when you’re going to want to sample some delicious street food or drink. You may even consider only buying from vendors who use low impact packaging like recycled paper that is fully compostable anywhere.

This is the latest installment in Vanessa Barrington’s weekly column, The Green Plate, on the environmental, social, and political issues related to what and how we eat.

Image: denkrahm

Vanessa Barrington

Vanessa Barrington is a San Francisco based writer and communications consultant specializing in environmental, social, and political issues in the food system.