Chewing gum stays off the streets when its polymers are recycled into other plastic products
The average piece of chewing gum is tasty for less than six minutes. You might gnaw longer on the flavorless gum a bit longer, but once you toss it out, the synthetic rubber in that gum will keep it from completely biodegrading for hundreds years. When you add in the fact that cities often spend nearly 70 million dollars per year to clean used gum off of sidewalks and streets, and a few moments of tasty chewing starts to look like a major investment, at least for the community at large. Anna Bullus, a designer from England, has some ideas on how to make a dent in the impact of your chewing and bubble-blowing, which is to start recycling it into products you’ll want to keep instead of sticking on the bottom of your chair.
The fleeting flavor of chewing gum is thanks to ingredients like corn syrup or beet juice, but the component that makes it so durable in our mouths (and on our sidewalks) is polyisobutylene. It’s derived from petroleum, and is most often used for its ability to be air-tight and stretchy at the same time. As such, it turns up in gas masks, air bladders in soccer balls, car tires and even explosives like C4. With a resume like that, polyisobutylene can obviously stand up to being chomped by your teeth, but it’s also really difficult to actually destroy. For instance, swallowed gum will survive a trip through your digestive tract essentially unscathed, which means that the millions of tons of gum that ends up in landfills each year will be sitting there for ages to come.
Gathering used gum
Fortunately, polyisobutylene can also be recycled, albeit not in the blue bins you may have at your home or office. We’ve been recapturing polyisobutylene from old tires for years, and it turns out that extracting it from wads of chewing gum is a feasible process as well. So instead of sitting on sidewalks or in landfills for ages, the synthetic rubber can be remade into reusable cups, galoshes, or even shoe soles. The catch in this kind of recycling is simply getting the gum gathered up in the first place.
Getting people to specifically recycle their gum may be Anna Bullus’ major innovation. While she’s been coming up with attractive products that promote gum as a recyclable material, she’s also made Gumdrop bins, which are special bins meant to exclusively collect old chewing gum. The bright pink, spherical bins are placed at eye level, with the intent of being as conspicuous as possible so people will pay more attention to how they dispose of their gum. They’re obviously not widely available yet, but cities and campuses that have been using them have seen some success. Aside from the rain boots and other products that can be made from the recycled polyisobutylene, there’s also been a reduction in the amount of gum dropped off the ground. Since scraping gum off a sidewalk can be ridiculously expensive, simply giving people more reasons to keep their gum off the ground makes this kind of recycling cost effective.
Tasty tree sap
If you don’t have anything like gum drops in your area, your community would probably appreciate it if you at least switched to chicle-based chewing gum. Chicle is made from tree sap, making it a bit more renewable than anything made from petroleum. It also biodegrades more quickly, so while it won’t be made into shoes, it won’t be sitting on sidewalks for quite so long either.
Source: World Hacks: A surprising new afterlife for chewing gum by Dougal Shaw, BBC News