Surprising Things You Can't Recycle (and What to Do Instead)

Why these slip through the cracks

Curbside recycling machinery is built for high-volume, standardized items — bottles, jugs, cans, cardboard. Two kinds of things defeat it: items that are too small (a common rule of thumb is that sorting equipment can't handle anything smaller than a credit card, so small items fall through the screens), and items made of fused, mixed materials that can't be separated back into one clean stream. When those land in your bin anyway, they become contamination — and as the EPA warns, non-recyclable items can contaminate a whole load of recyclables and even damage the equipment. That's why 'when in doubt, throw it out' beats hopeful guessing.

Paper that isn't really paper: receipts & coffee cups

Receipts. Most are printed on thermal paper, coated with a heat-sensitive layer of BPA or BPS. That coating dissolves at the pulping stage and contaminates recovered paper fiber, so thermal receipts can't be recycled — and shouldn't be composted either, since the chemicals don't break down. A quick test: thermal paper leaves a dark mark when you scratch it with a fingernail. Trash them. (Plain ink-printed receipts can go with paper.)

Disposable coffee cups. A paper hot cup is mostly paper, but it's lined with a thin layer of polyethylene plastic fused to the paper to make it waterproof. Recyclers can't cleanly separate the two, so most cups go to landfill. Put the cup in the trash; the plastic lid can be recycled where that resin is accepted, and a paper sleeve can go with cardboard. A reusable cup avoids the whole problem.

Glass that isn't bottle glass: mirrors, Pyrex & ceramics

Container glass (bottles and jars) is the only glass your recycling program wants. Three lookalikes ruin it:

Mirrors carry a metallic reflective coating and a different glass formulation, so they won't melt uniformly with bottle glass — they create defects and damage equipment.

Pyrex and ovenware are heat-treated glass with a much higher melting point. In a glass furnace they don't fully melt, forming solid lumps that weaken and crack new bottles.

Ceramics (mugs, plates) behave the same way. None of these belong in glass recycling. Donate usable pieces; wrap broken ones safely and put them in the trash.

Small or mixed plastics: utensils, straws & old Tupperware

Plastic utensils and straws are a double problem: they're too small and light for the sorting line (they slip through screens or get blown off by air jets), and they're often a mix of resins with food residue. The EPA lists plastic cutlery among non-recyclable items. Trash them, or switch to reusables.

Old Tupperware and rigid food containers are usually #5 polypropylene or a mix of resins. #5 is a gray-area plastic — accepted in some cities, rejected in many — so check your local program's list and the resin code before binning it. If a container is just scratched or stained, it's simply worn out: reuse or donate it if usable, look for a store take-back program, or otherwise throw it away.

Multi-material packaging: K-cups & chip bags

Single-serve coffee pods (K-cups) combine a plastic cup, an aluminum foil lid, a paper filter and wet grounds — and they're tiny. A curbside facility can't separate or sort them, so they generally go in the trash unless you fully pull them apart (compost the grounds, peel the foil, recycle the cup only where that resin is accepted). Some brands run mail-back programs.

Chip bags and snack wrappers are multilayer laminates — plastic fused with a thin metallized film. Recycling plants can't delaminate them, so they aren't curbside recyclable and don't belong in store plastic-bag drop-offs either. Trash them, or use a specialty mail-back program like TerraCycle where a brand sponsors one.

The one habit to drop: wishcycling

Putting non-recyclables in the bin hoping they'll somehow get recycled — 'wishcycling' — is counterproductive. The EPA is blunt about it: don't put items in your recycling bin unless you know they're accepted, because a single contaminated load can send otherwise-recyclable material to the landfill and drive up costs that have shut down curbside programs.

The fix is simple: check your local recycling provider's accepted-materials list (it varies a lot by city), rinse what you do recycle, and when you're unsure about an item, put it in the trash rather than guess.

For a plain-English breakdown of what the numbers and arrows mean, see our guide to recycling symbols and numbers.

Frequently Asked Questions

Why can't you recycle receipt paper?

Most receipts are thermal paper coated with BPA or BPS, a chemical layer that dissolves during paper pulping and contaminates the recovered fiber. That makes thermal receipts non-recyclable — and they shouldn't be composted either, since the coating doesn't break down. If a receipt leaves a dark mark when you scratch it, it's thermal; put it in the trash.

Can you recycle K-cups?

Generally not in curbside recycling. A single-serve pod is a mix of plastic, aluminum foil, a paper filter and coffee grounds, and it's too small for sorting machinery to handle. Throw them in the trash unless you fully separate the parts, or use a brand mail-back program where one exists.

Should I throw away old Tupperware?

If it's cracked, warped or badly stained, yes — it's worn out. For recycling, check the resin code and your city's list: most Tupperware is #5 plastic, which only some programs accept. If it's still usable, reuse or donate it, or look for a store take-back program rather than binning it.

Are disposable coffee cups recyclable?

Usually not. Paper hot cups have a polyethylene plastic lining fused to the paper that recyclers can't cleanly separate, so most go to landfill. Trash the cup; the lid may be recyclable where that plastic is accepted, and a paper sleeve can go with cardboard. A reusable cup is the better fix.