What NOT to Put in a Compost Drop-Off Bin

Universal No-List

Never put these in any compost drop-off bin: plastic bags, pet waste, diapers, personal hygiene products, recyclables (glass, metal, cardboard), or non-food items of any kind. Contamination ruins entire batches of compost and can shut programs down.

The Universal Rejection List

These items are rejected at every food scrap program — municipal, community garden, private, and smart bin:

Plastic Bags

Even bags labeled "biodegradable" or "eco-friendly" are not accepted unless they're BPI-certified compostable (and even then, many programs ban them). Plastic bags don't break down in composting conditions — they contaminate the finished compost with microplastics.

Pet Waste and Cat Litter

Dog and cat feces contain pathogens (including Toxoplasma gondii from cats) that are not reliably eliminated even in commercial composting. No legitimate food scrap program accepts pet waste.

Diapers and Hygiene Products

Human waste creates the same pathogen concerns as pet waste. Conventional diapers also contain plastic and superabsorbent polymers that don't compost. Even some "compostable" diapers aren't accepted at most programs.

Recyclables

Glass jars, metal cans, cardboard boxes, paper cartons, and plastic containers go in your recycling bin — not in compost. Adding recyclables to a compost bin prevents them from being recycled and can contaminate the compost with non-organic materials.

Non-Compostable Packaging

Produce stickers (remove them from fruit), rubber bands around vegetables, plastic twist ties, foam trays, and any plastic or foil packaging. If food came in it, remove the packaging before adding the food to your compost container.

Wax-Coated Cardboard and Treated Paper

Coffee cups with plastic lining, wax-coated cardboard, glossy printed paper, and most takeout containers. These don't break down in composting conditions even though they're made primarily of paper.

Why Contamination Matters

A single contaminated bag — especially one containing plastic — can ruin an entire batch of compost. Commercial composting facilities have sorting equipment, but not all contamination is caught. Persistent contamination from a single drop-off site can cause programs to reduce service or shut down entirely. The rule is simple: when in doubt, leave it out.

Frequently Asked Questions

Only if they're BPI-certified AND your specific program accepts compostable foodware. Many programs — including Chicago — do not accept compostable cups, plates, or containers even if they're labeled compostable. Check your program's specific list. If unsure, put them in the trash.

No. Produce stickers — the small round price and PLU stickers on fruit — are typically made of plastic or vinyl and are not compostable. Remove them before adding fruit scraps to your compost container. This is a small but genuinely impactful step, since thousands of produce stickers in a commercial batch can add up.

If you realize mid-drop that you've added something you shouldn't, try to remove it if possible. If you can't, notify the program organizer. For future visits, double-check your container before leaving home. Contamination happens — what programs care about is whether it's a pattern from a specific site or participant.