As I mentioned before, I’m spoiled when it comes to recycling. Our local recycling facility is single-stream and accepts virtually everything - including plastic #6: polystyrene. Furthermore, they accept the much harder-to-place version, expanded polystyrene (EPS). I never knew it, but apparently not all recycling facilities accept this version of #6, so let’s look at it a bit closer.
What is EPS?
EPS is commonly known as “Styrofoam”, although technically this is Dow’s trademarked name for a blue-tinted extruded polystyrene foam. The more common white material that we encounter in our daily lives - in our coolers, lunch trays, packing peanuts, ad infinitum - is expanded polystyrene. It is generally manufactured by heating small polystyrene resin beads and expanding them with steam; EPS is roughly 95% air, which, while making it a good thermal insulator and cheap to ship, also accounts for its significant volume in landfill space (4). And because polystyrene has approximately a 100 year half-life, it’s easy to extrapolate this double-whammy impact on our environment - lots of space and slow to break down.
The good news is that polystyrene is a thermoplastic: it can be melted and set over and over again with minimal property loss, so it’s a prime opportunity to recycle it into another polystyrene form. The bad news is that because of it’s air content, it tends not to be cost-effective to harvest, which is the reason so many recycling programs won’t accept it in their bins. It takes up space that could be filled by paper, metals, or dense versions of plastic.
How can you recycle it?
In the lab, the best thing is to upcycle it. Upcycling will be a common theme at Labconscious: it’s an umbrella term to reuse or repurpose an item. Coolers and packing peanuts can be saved and stored for later use. If that’s not an option and recycling is the only way to go, it should be free from tape and other debris, and basically be in good condition. It will have to get densified (exactly what it sounds like) prior to getting processed, and there are lots of good options for mailing it to a facility (see resources below), including the fact that some biotech companies (NEB for one) will send you pre-paid labels to ship their EPS coolers and boxes back to them. Better yet, start an EPS recycling program in your lab like Andrew Markley did at UW-Madison! If you’re up for it, there are also some cool niche programs that gather EPS, densify it, and then convert it into surfboards (and bike helmets) for kids like Waste to Waves.
So while your in-house recycling vendor might not currently accept EPS, there’s plenty of great options for you to start a program to ensure this material doesn’t end up in the landfill. We here at Labconscious would love to get a comprehensive resource here for Universities and Industry to refer to and make everyone’s life easier, so if you have done this, or learn about the process while doing it, be sure to share any tips with us! Check out the resources below for more info.
Good EPS Resources
1. Andrew Markley - EPS Upcycling Pioneer at UW - Madison
2. EPS Industry Pack for Starting an EPS Recycling Program
3. EPS Recycling Centers
4. EPS FAQ