Number 6 plastic is technically recyclable, but the vast majority of curbside recycling programs do not accept it. Most #6 plastic ends up in landfills because recycling it is expensive, the material is lightweight relative to its volume, and very few processing facilities are equipped to handle it. If you’re holding a piece of #6 plastic and wondering whether to toss it in the blue bin, the answer in most cities is no.
What Number 6 Plastic Actually Is
The number 6 inside the recycling triangle identifies polystyrene, a petroleum-based plastic made from styrene. It comes in two forms, and you’ve almost certainly used both. Rigid polystyrene shows up as disposable plastic cups, coffee cup lids, CD and DVD cases, plastic utensils, and clothes hangers. Expanded polystyrene, better known by the brand name Styrofoam, is the white foam used in takeout containers, egg cartons, packing peanuts, and the molded blocks that cushion electronics in their boxes.
The distinction between rigid and foam matters for recycling. Rigid polystyrene is denser and slightly easier to process, while expanded polystyrene is roughly 95% air. That air content makes foam extremely costly to transport. A full truckload of foam weighs almost nothing, meaning haulers spend fuel moving mostly air to a processing facility that may be hundreds of miles away.
Why Most Programs Reject It
Recycling works as a market. Facilities collect materials, process them, and sell them to manufacturers who turn them into new products. For aluminum, cardboard, and certain plastics like #1 (PET) and #2 (HDPE), this market is strong. For #6 polystyrene, it barely exists.
The economics fall apart at nearly every step. Polystyrene is light, so collection costs per ton are high. It breaks into small pieces easily, contaminating other recyclable materials in sorting facilities. Food residue from takeout containers and coffee cups makes much of it unsuitable for reprocessing. And demand for recycled polystyrene is low because virgin polystyrene is cheap to produce. The result is that most municipal recycling programs explicitly exclude #6 plastic. Putting it in your curbside bin doesn’t just fail to recycle it. It can contaminate an entire batch of otherwise recyclable material.
Where You Can Actually Recycle It
Some cities and counties do operate drop-off locations specifically for polystyrene. High Point, North Carolina, for example, runs a recycling facility with a foam densifier, a machine that compresses expanded polystyrene into dense blocks that are economical to ship. Both residents and businesses can bring clean polystyrene to the facility for processing. Similar drop-off programs exist in scattered locations across the country, though they are far from universal.
To find out whether a drop-off option exists near you, check your city or county’s waste management website. Search for “polystyrene” or “foam recycling” along with your city name. Some shipping and packaging stores also accept clean packing peanuts and foam blocks for reuse, which is a simpler alternative to recycling.
How to Prepare Polystyrene for Recycling
If you do have access to a facility that accepts #6 plastic, preparation is straightforward but important. Remove any tape, labels, or stickers. Rinse off food residue completely. A greasy foam takeout container that won’t come clean is not recyclable, even at a facility that accepts polystyrene. Separate rigid polystyrene from foam, since some programs accept one but not the other. Break down large foam pieces to save space, but don’t crumble them into small bits that become difficult to process.
Health Concerns With Polystyrene
Beyond the recycling question, many people searching for information about #6 plastic are also wondering whether it’s safe. Polystyrene can leach small amounts of styrene into food and beverages, particularly when heated. The Agency for Toxic Substances and Disease Registry confirms that styrene transfers from polystyrene packaging into food. The FDA sets a limit of 0.1 milligrams per liter of styrene in bottled drinking water, and the EPA considers lifetime exposure at that same concentration safe.
At normal use levels, the amounts that migrate into food are very small. But heating polystyrene, such as microwaving a foam container, increases leaching. If you regularly eat or drink from #6 containers, switching to glass, stainless steel, or plastics labeled microwave-safe (#5 polypropylene) reduces exposure.
What Happens to Polystyrene That Gets Recycled
When polystyrene does make it to a recycling facility, it’s typically processed in one of two ways. Mechanical recycling melts it down and reshapes it into new products like picture frames, crown molding, or rigid insulation. This works best with clean, rigid polystyrene.
A newer approach, chemical recycling, breaks polystyrene down at the molecular level. Heating polystyrene to 400 to 600 degrees Celsius through a process called pyrolysis can recover styrene monomer, the original building block of the plastic. Researchers have developed catalytic processes that convert polystyrene pyrolysis oils into high-value chemicals like benzene, toluene, and ethylbenzene with yields above 73% of the starting material’s weight. These technologies could eventually make polystyrene recycling economically viable at scale, but they are not yet widely deployed.
Practical Alternatives to Recycling
Given how difficult #6 plastic is to recycle, the most effective strategy is reducing how much of it you use in the first place. Bring your own reusable cup to coffee shops. Request no foam packaging when ordering electronics or furniture. Choose eggs in cardboard cartons over foam ones. When ordering takeout, some restaurants now use compostable or #5 plastic containers if you ask.
For foam packing materials you already have, reuse is more realistic than recycling. Save packing peanuts and foam inserts for your next shipment. Offer them on community boards or to local shipping stores. Polystyrene doesn’t degrade in landfills for hundreds of years, so keeping it in circulation through reuse, even informally, is a meaningful step when recycling infrastructure doesn’t exist in your area.