Are pizza boxes recyclable?
Usually yes
Yes. Empty the box and recycle it with cardboard. Grease is not the problem people think it is, but leftover food is.
Follow it down the line
Three different questions hide inside "is this recyclable?", and the answer can change at each step.
The material · Yes
Is the material recyclable?
A pizza box is corrugated cardboard, one of the most valuable and widely recycled materials in the stream. The belief that grease ruins the batch is not a small exaggeration so much as the wrong shape of claim, and there is a study that shows exactly why. WestRock tested it in 2020, and the mechanism is worth understanding because it explains the whole confusion. Grease is hydrophobic, so at a high enough concentration it genuinely does interfere with the bonding between fibers that gives paper its strength. That real effect is what the myth is built on. The question nobody asks is dose. Boxes in the recycling stream carry roughly 1 to 2 percent grease by weight, and pizza boxes amount to about 2.6 percent of the old corrugated container stream. Strength loss only becomes significant when boxes reach something like 20 percent of the furnish, and even there it costs about 5 percent of strength; below 10 percent the loss is low. Real conditions are nowhere near it. The study concludes there is no significant technical reason to prohibit post-consumer pizza boxes from the recycle stream. Cheese turns out to behave the opposite way. It is fats and proteins, proteins are hydrophilic, and it does not hinder inter-fiber bonding at all; it also solidifies and gets screened out during pulping. So the two things everyone worries about fail to be problems for two different reasons. The grease is real but far too dilute to matter, and the cheese removes itself.
Sources: American Forest & Paper Association, WestRock: Incorporation of Post-Consumer Pizza Boxes in the Recovered Fiber Stream
The facility · Yes
Will a sorting facility recover it?
A pizza box is ordinary corrugated cardboard by the time it reaches a facility, the same size, shape and rigidity as the rest of the old corrugated container stream, so nothing about sorting it is unusual. The demand side is settled rather than marginal: AF&PA member companies representing 94 percent of total annual OCC consumption accept pizza boxes. What has to be true is that the box arrives empty, and the mill's own process is where that line gets drawn. Pulping is a wash rather than a sort. Recovered paper is mixed with water and agitated until the fibers release, and the material that is not fiber, the adhesives and coatings and plastic and tape, is separated out and sent for disposal rather than recovered. Grease that has soaked into the board is dilute enough to pass through all of that unnoticed. A crust, a wedge of leftover pizza or a plastic pizza saver is not: it is a solid object that has to be screened out, and it will have ridden through a collection truck and a sorting line to get there. Leftover food is what the industry asks you to remove. The grease is not.
Sources: The Recycling Partnership: pizza box research, AF&PA: Design Guidance for Recyclability
Your curbside program · Varies
Will your curbside program take it?
Acceptance has shifted notably in recent years as the grease research circulated, but programs have not moved in step, and the wording differs in ways that matter. New York City recycles lightly-soiled pizza boxes with mixed paper and cardboard and says so in those words, which sets a threshold rather than granting a flat yes. Cuyahoga County accepts them with a parenthesis doing the same work: no food, no excess cheese or grease. Portland draws the cleanest line of the three, because it has two bins to draw it with. A greasy box with no sauce or food on it goes in recycling; a food-soiled one goes in the compost cart, emptied and with any liner removed. That is not a program hedging. It is a program that has somewhere better to send the boxes which really are too far gone, which is a luxury most places do not have. A minority of programs still refuse pizza boxes altogether. This stays the layer where the answer genuinely depends on where you live, and the thing to look for in your own program's wording is whether it draws its line at food or at grease, because those are different rules and only one of them is supported by what happens at the mill.
Sources: NYC Department of Sanitation, Portland.gov: Compost, what goes in the bin, CuyahogaRecycles: paper and boxes
What you need to do
- Empty the box completely; leftover crusts and toppings are contamination, and always were
- Remove the plastic pizza saver and any paper liner
- Flatten it so it sorts correctly and takes less space
- Tear off any section soaked through with oil
- Read your program's wording carefully: a rule about food and a rule about grease are not the same rule
Where else it can go
Curbside compost, where it exists
Cardboard composts well, and a box too food-soiled for recycling is still perfectly good compost feedstock. Portland routes them explicitly: food-soiled boxes to the compost cart, greasy but food-free boxes to recycling. Where a program runs both carts this is the answer rather than a consolation prize.
Remove any plastic pizza saver and all food first, and empty the box either way.
Home composting
Torn into pieces, corrugated is a useful carbon-rich brown layer in a home heap, and the grease that disqualifies a box from a paper mill is irrelevant to a compost pile.
Tear it up; a whole flat box mats together and takes a long time to break down.
Tear and split
If only the base is saturated, tear off the clean lid and recycle that. The oily base goes to compost or landfill, which turns one ambiguous item into two clear ones.
Common mistakes
- Leaving a slice or crusts in the box, when food is the actual contaminant, not grease
- Leaving the plastic pizza saver in the middle
- Recycling a box that has soaked through completely
- Binning an ordinary greasy box out of caution. Boxes in the stream average 1 to 2 percent grease by weight, and strength loss does not become significant until they are around 20 percent of the furnish
- Scrubbing or cutting grease off the cardboard before recycling it, which is effort spent on the one thing the mill was never bothered by