The Ins and Outs of Recycling Plastics

Plastics are some of the more confounding materials to recycle. There are so many different types of plastic that even the most eco-friendly among us sometimes doesn’t know what to do with our milk jugs and Chinese takeout containers.

First, a little background information. Plastics are created by heating petroleum and other materials to form polymers, or chains of molecules. Manufacturers can manipulate the conditions under which materials are heated to form different types of plastic, many of which are integral to our day-to-day lives: polyethylene terephthalate (PET), which is used to make soda and water bottles; high-density polyethylene (HDPE), which is used in milk jugs; and polyvinyl chloride (PVC), which is often used to manufacture pipes.

Because plastics are petroleum based, they are also famously slow to break down in landfills. Plastics’ impact on the environment, combined with recent health concerns (some plastics have been found to leach carcinogens and other harmful substances), has caused many individuals and communities to significantly curb the use of plastic water bottles and other containers. Nevertheless, plastic products are still a deeply ingrained part of all of our lives, so the issue of how to dispose of plastics is not one that will disappear any time soon.

Thankfully, some of the more widely used types of plastic are now recyclable in many communities. The resin identification code — that hieroglyphic-like number and triangle found on many plastic products — tells you what type of plastic you’re dealing with, and therefore whether it’s recyclable. Each city’s recycling program is different, but, generally, there are a few types of plastic that are considered highly recyclable. In New York City, for instance, plastic products labeled 1 (PET) and 2 (HDPE) are recyclable, while those labeled 3 through 7 (encompassing vinyl products, plastic cutlery, Styrofoam peanuts, most shopping bags and many other items) are not.

Once recyclable plastic products are handed over by the consumer, the products are trucked off to a recycling center, where they’re sorted, baled and sent to a facility that cleans the items and grinds them into small flakes. A flotation tank is used to remove yet more contaminants, and then the flakes are dried, melted and formed into pellets. At that point, the pellets can be shipped off to manufacturers to make new products. Hundreds of companies now use recycled plastics to manufacture thousands of items as diverse as park benches, clothing, carpets, trash bags and even lumber.

Like many things environmental, plastics recycling has fueled its share of debate. For instance, some environmentalists have pointed out that it takes a great deal of water to recycle plastics — up to 100,000 gallons of water per day at some facilities — while others argue that the benefits of keeping even some plastics out of our landfills are worth the extra water usage. There also has been a backlash against the practice — common in some parts of the country — of recycling plastics into items that cannot be recycled again, which does little to curb the consumption of petroleum in producing “virgin” plastics. Nevertheless, plastics recycling has come a long way since widespread recycling started to take hold in the 1980s, and it is hard to argue that the progress that’s been made so far hasn’t contributed to the greening of our planet, and our lives.