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Photos: Decoding plastics

Which plastics can be recycled? Which are safe to use? Our guide steps through the seven major types to explain.

Elsa Wenzel
2 min read
Click on this image for a photo gallery showing what's within the major types of plastic.
Click on this image for a photo gallery showing what's within the major types of plastic. Corinne Schulze/CNET Networks

A growing body of scientific evidence makes plastics increasingly less attractive to "green" consumers. Hormone-altering substances seep from drinking bottles. Great plastic garbage patches swirl in the ocean. And plastic bits have been found to concentrate poisons at levels a million times higher than in the water. Many people don't even know that most plastic is made from petroleum.

But agriculture giants including Archer Daniels Midland and small companies such as Cereplast are baking plastic from corn, soy, potatoes, and tapioca. Start-ups are even exploring pig urine and carbon dioxide to make plastics. Bioplastics could make up 30 percent of the plastics market by 2030, according to Helmut Kaiser Consultancy.

Still, most plastics continue to be made from petroleum or natural gas, which, although increasingly expensive, remain cheaper than using plants.

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Fossil fuel plastics involve toxic chemicals to produce, can harm human health, pollute ecosystems, and are rarely recycled. Some people struggling to eliminate daily use of plastics find it nearly impossible.

However, codes marking many plastic products can help people figure out what's inside the bottle and what to do with it when it's spent, depending upon regional recycling rules.

To help recyclers, the plastics industry more than two decades ago started a labeling system that identifies seven major types of plastics by a numeric stamp on the bottoms of bottles. But what do the numbers mean?

I took a look at the seven categories in products from around my apartment. I retain a fair share of ecologically-damaging habits, but it hurt to make a trip to the store for polystyrene cups (No. 2) and root beer for the polyethylene six-pack rings (No. 4). The PET water bottle (No. 1) was mailed to me in a press package from a company that makes "green" products. However, while sometimes I splurge on bubbly bottled water, I try to use a stainless steel Klean Kanteen for flat water. (Ahem, the HDPE foot powder (No. 2) was left by a guest.) Check out the photo gallery for more.