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Thou Shalt Sort Thy PlasticsHow bad is it to mix your soda bottles with your yogurt cups?

By Brendan I. Koerner
Posted Tuesday, May 6, 2008, at 7:34 AM ET

(Continued from page 1)

The nastiest of those potential contaminants isn't your polypropylene but rather PVC (aka plastic No. 3). Though it's increasingly rare in the United States due to concerns over dioxin emissions during manufacture, PVC is still prevalent enough to ruin many a load of otherwise recyclable PET. The stuff is the bane of recyclers everywhere: A single PVC bottle can irrevocably contaminate an entire 800-pound load of otherwise desirable PET, rendering it unfit to be made into new products—PVC forms acids when mixed with PET, and those acids can make the recycled plastic unacceptably fragile. Because of this danger, many recycling facilities now employ machines such as FlakeSort, which analyzes the PVC content of processed plastic "flakes" before they're sold on the open market.

Those flakes are rarely turned into new food-grade products but are "downcycled" into pipes, fence posts, and picnic tables—exactly the sorts of products that recycling facilities reject during their initial screenings. So when these post-consumer items are no longer wanted, they're ultimately destined for the landfill or for an incinerator in Guangdong Province.

Despite its labor-intensive and relatively inefficient nature, plastics recycling still makes long-term sense. The EPA estimates that making a ton of plastic out of used PET bottles saves 55.9 gigajoules of energy over manufacturing a ton of plastic from scratch. And in 2005, Britain's Waste Resources and Action Programme analyzed (PDF) 60 different life-cycle scenarios for plastics. The organization concluded that recycling was invariably superior to landfilling, in terms of net carbon emissions. Recycling was clearly preferable to incineration, meanwhile, in more than 76 percent of the scenarios. It bears noting, however, that the WRAP study doesn't seem to have factored in the energy used to transport plastics to overseas incinerators nor the possibility that those incinerators lack proper emissions safeguards. (Environmentalists fear that burning PVC, in particular, can lead to toxic emissions, and that even ostensibly safer plastics contain heavy metals in their pigments.)

The equation tilts more heavily in recycling's favor once you consider the recent rise in oil prices. About 8 percent of the world's oil supply goes toward making plastics—half into the actual feedstock and half to power the manufacturing plants. With crude futures currently hovering around $120 barrel, there's a lot of incentive for companies to figure out how to use recycled flakes in lieu of virgin plastic. If this trend continues, maybe they'll even start jonesing for your yogurt cups.

Is there an environmental quandary that's been keeping you up at night? Send it to , and check this space every Tuesday.

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Brendan I. Koerner is a contributing editor at Wired and a columnist for Gizmodo. His first book, Now the Hell Will Start, is out now.
Illustration by Robert Neubecker.
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Notes from the Fray Editor

"Make your own yogurt! Get rid of yogurt cups forerver!" says DIM, and helpfully gives a recipe. Fordtruck5speed is worried about some of the posts: "I just hope the terrorists aren't reading this"—find out why here.

Comments from the Fray

Excellent piece. I've always thought it was a bad idea for municipalities to list specific items ("yogurt cups," "margarine tubs," etc) instead of just saying what kinds of plastics they take. My community distributed a flyer identifying these by number (eg, 1, 2, and 3) and explaining how to look for the number on the package. Not all yogurt cups are made of the same plastic; I switched brands of yogurt after the city released these guidelines.

--penelopekay

(To reply, click here)

I actually contacted the yogurt manufacturer once and asked them why they don't make their containers out of the most commonly recyclable 1 or 2 type plastic. Their response was that they choose the plastic that burns the cleanest and decomposes the fastest, because their research showed that a majority of the cups do not get recycled.

--Ringomon

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