The Complete Guide to Polystyrene Recycling
Polystyrene, identified by the resin code #6 on plastic products, is one of the most widely used plastics in the world. From the foam cups that keep your coffee hot to the protective packaging that cushions your new electronics, polystyrene is everywhere. Yet despite its ubiquity, recycling this material remains one of the biggest challenges in modern waste management.
Why Is Polystyrene Hard to Recycle?
The difficulties begin with the material itself. Expanded polystyrene (EPS) is roughly 95% air by volume, meaning a truckload of foam cups contains very little actual recyclable material relative to the space it occupies. Transportation costs become prohibitively expensive when you are essentially hauling air across long distances. Contamination is another major hurdle. Food residue from takeout containers and coffee cups makes the material difficult to process without thorough cleaning. Finally, the economics are stark: recycling polystyrene can cost over $1,000 per ton at small scale, while landfill disposal costs just $30-50 per ton.
How to Identify Polystyrene
Look for the #6 recycling symbol stamped on the bottom of containers. Polystyrene comes in two main forms: expanded polystyrene (EPS), which is the white, beaded foam used in cups and packaging, and extruded polystyrene (XPS), which is the denser, colored foam board used in building insulation. Both are recyclable, but through different processes and at different facilities.
The 4-Step Consumer Recycling Process
Step 1: Identify. Check for the #6 resin code and determine whether you have EPS or solid polystyrene. Remove any labels or tape if possible.
Step 2: Clean. Rinse food containers thoroughly with water. Remove any food residue, as contamination is the number one reason polystyrene loads get rejected at recycling facilities. Allow items to dry completely.
Step 3: Find a Location. Since most curbside programs do not accept polystyrene, you will need to locate a specialized drop-off point. The EPS Industry Alliance maintains an online recycling locator map that helps you find the nearest facility. Many shipping stores, packaging retailers, and dedicated recycling centers accept clean EPS.
Step 4: Transport. Gather your clean polystyrene and bring it to the drop-off location. If possible, break larger pieces into smaller ones to save space in your vehicle, but do not compress EPS into a ball as this can make it harder to process.
Mechanical vs. Chemical Recycling
Mechanical recycling involves physically processing polystyrene through compaction, shredding, and extrusion. The material is compressed to as little as 1/50th of its original volume, then melted and reformed into pellets. These pellets become new products like picture frames, park benches, and crown molding.
Chemical recycling takes a fundamentally different approach by breaking polystyrene down at the molecular level. Methods like pyrolysis heat the material to 400-500 degrees Celsius in an oxygen-free environment, converting it back into styrene oil. Depolymerization goes even further, recovering the original styrene monomer that can be repolymerized into virgin-quality polystyrene.
Finding Recycling Locations
The EPS Industry Alliance operates a comprehensive map of drop-off locations across the United States. Additionally, many mail and packaging stores accept clean EPS packaging materials for reuse. Some municipalities have begun adding polystyrene collection to their special recycling events, even if they do not include it in regular curbside pickup.
The infrastructure for polystyrene recycling is growing every year. New facilities are opening, chemical recycling technologies are scaling up, and the 2025 milestone of food-grade recycled polystyrene has given the industry renewed momentum. By taking the time to properly recycle your polystyrene waste, you are contributing to a system that gets stronger with every participant.