Recycle better: A primer on plastics

June 21, 2021

Resource

Take the confusion out of plastic recycling.

Did you know that just 8.7% of all plastic in the U.S. is recycled? One of the main reasons: consumers get confused about proper plastic recycling.

To help take the guesswork out of plastic recycling—and stop hope- or wish-cycling—we put together this plastic recycling primer.

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The problem with plastic

Because plastic is cheap and practical, it’s ubiquitous. But that ubiquity comes at a cost. For one, plastics represent 50–80% of the waste on beaches, oceans, and seabeds. The World Economic Forum estimates that by 2050 there will be more plastic in the ocean than fish. Plastics are a nightmare for terrestrial ecosystems, too. Who hasn’t seen plastic bags in our local parks and awful videos of animals caught six-pack rings?

Different types of plastic

Plastics fit into seven recyclability categories indicated by the numbers in the “chasing arrows” printed or stamped on products.

Of the seven categories, many recycling centers accept #1 and #2 plastics, and they make up the bulk of all plastic recycled annually.

#1 Polyethylene Terephthalate (PET/PETE)

PET/PETE plastics are commonly used in single-use beverage bottles, food packaging, carpets, and thin plastic films.

#2 High-Density Polyethylene (HDPE/PEHD)

These pigmented plastics have a higher density, so they’re often used for things like milk cartons, shampoo bottles, cleaning containers, toys, and more.

The rest—#3–#7—commonly end up in landfills, get burned, or otherwise end up in the environment.

#3 Polyvinyl Chloride (PVC)

PVC is nonconductive, strong, and resistant to chemicals, making it useful in building products (pipes, fittings, decking) and other applications that require solid yet workable materials. Sadly, just 1% of PVC gets recycled, and it contains many harmful chemicals linked to serious health and environmental problems.

Always check with your local recycling authority to see if they accept PVC material. When PVC reaches its end-of-life or is no longer needed and can’t be recycled, try to upcycle the material or donate it.

#4 Low-Density Polyethylene (LDPE/LD)

LDPE, a thermoplastic, can be heated, cooled, and shaped into different forms. Plastic shopping bags are the most common LDPE products, but other common uses include computer components, lids, food containers, and tubing. Many recyclers don’t accept LDPE plastic products because it gums up sorting equipment and contaminates more desirable plastic streams.

Keep plastic bags separate from commingled bins and contact your local recycling authority to see if they accept #4 plastics. Try to limit or eliminate their use and opt for eco-friendly replacements such as fabric bags instead. To recycle #4 plastic, keep items separate from other recyclables and drop them off at designated places like local grocery stores.

#5 Polypropylene (PP)

PP is the most common plastic found in auto parts and accessories, kitchenware, storage bins, shipping materials, disposable cups and plates, prescription bottles, and more. Due to its short life span, most PP gets landfilled, making it one of the least recycled plastics—less than 1% gets recycled.

Many curbside services don’t accept #5 plastics, so check with your recycling authority before tossing it in a commingled bin. Otherwise, reserve #5 plastic to drop off at a location that accepts it.

#6 Polystyrene (PS)

Also known as Styrofoam, this plastic is often used as insulation and packing material. You’ll find Polystyrene in single-use cutlery, cups, food containers, packing peanuts, foam plates, and more. Few recycling centers accept PS, because it’s virtually unrecyclable.

Avoid products that contain PS, or reuse common items (particularly packaging) when possible. Check with shipping companies to see if they’ll take PS shipping material back or use this interactive map to find a PS recycler near you.

#7 Plastics

This “recycling” category is a misnomer because it’s not really recyclable. #7 plastics cover a wide array of tough material recyclers won’t touch. Their durability is precisely what makes them so unrecyclable—a reason to avoid them altogether. Common #7 plastics include transparent packaging made from polycarbonate (PC) like CD cases, light sockets, fuse boxes, and car interiors.

The second type of #7 plastic is acrylic (PMMA), also known as Plexiglass, used in eyewear and transparent surfaces. The third is Acetal (Polyoxymethylene, POM), a tough plastic used in gears and other mechanical applications. Nylon (PA) is another type of #7 plastic used in rubber manufacturing to create clothes, textiles, and molded parts. Lastly, acrylonitrile butadiene styrene (ABS), is used in injection molding and 3D printing.