The short answer is: yes for most municipal commercial composting programs in 2025, with one caveat about grease level. The longer answer involves understanding why pizza boxes were historically excluded from composting and what’s changed.
For about a decade — roughly 2005 to 2015 — most municipal compost programs explicitly excluded pizza boxes from their accepted material list. The reason was that greasy pizza boxes were thought to contaminate the composting stream, slow down the breakdown process, and potentially attract pests. Composters preferred clean cardboard for their feedstock.
Then operations improved. Compost facility design evolved. Sorting technology got better. The understanding of how grease actually behaves in a hot windrow composting environment got more nuanced. By 2018-2020, most major municipal compost programs had changed their policy to accept pizza boxes, including the greasy ones. The change isn’t universally complete (some smaller programs still exclude them), but the trajectory is clear: pizza boxes are increasingly accepted in commercial composting.
This article walks through the specifics — what’s changed, how greasy is too greasy, what to do with the leftover cheese, when to compost versus recycle versus trash, and the regional variation in what’s actually accepted.
What changed
The shift in policy reflects a few things:
Hot composting handles grease. Industrial composting operating at 130-150°F can process modest amounts of food residue including grease without significant problems. The temperature and active microbial community break down the fats relatively quickly.
Sorting improved. Modern commercial composting facilities have better mechanical sorting and screening systems that can handle the somewhat-contaminated cardboard from pizza boxes. The boxes don’t need to be perfectly clean.
The volume math improved. Across millions of pizza-eating households, the cumulative volume of pizza boxes is significant. Diverting them from landfill (where they don’t break down anyway because landfills are anaerobic) to commercial composting (where they do break down) is meaningfully beneficial.
Specific operational learnings. Some compost facilities discovered that grease in pizza boxes actually accelerated some aspects of the process. Other facilities found minimal impact either way. The historical fear of grease ruining composting wasn’t borne out by operational data.
The result is that most municipal commercial composting programs now accept pizza boxes — including the standard greasy paper-corrugated kind.
The 2025 reality by region
Geographic variation matters. Specific regions and their policy:
San Francisco/Bay Area: Pizza boxes accepted in compost. Recology (the municipal hauler) has been clear about this for years.
Portland/Oregon: Pizza boxes accepted in commercial composting.
Seattle/Washington: Pizza boxes accepted.
Most California municipalities: Generally accepted, with rare exceptions.
Boulder/Colorado: Pizza boxes accepted.
New York City: Yes in the (since 2024) expanded city compost program.
Toronto/Canada: Yes in the city’s organic waste program.
Most major metropolitan areas: Generally yes.
Smaller municipalities and rural areas: Sometimes yes, sometimes no. Check your local program.
For the specific question “does my city accept pizza boxes in compost?” the way to answer is:
- Check your city/county solid waste website
- Look for the accepted materials list
- Confirm pizza boxes are included
- If unclear, call the solid waste department or email them
Don’t assume one way or the other. The answer has been shifting across cities, and you want to confirm for your specific location.
The grease question — how greasy is too greasy
Even where pizza boxes are accepted, there are sometimes practical limits. The grease level guidelines:
Lightly greasy (typical pizza box): Almost always fine. The standard pizza box with grease stains from one pie is well within what commercial composters accept.
Moderately greasy (multiple pizzas, lots of dripping): Usually fine but check your local program for specifics.
Heavily greasy (saturated with oil): Some programs accept this; some don’t. The very greasy boxes from highly-oily pizzas (extra cheese, lots of pepperoni grease) sometimes have processing issues.
Soaked or dripping: Probably not acceptable. The box is functionally compromised, and the excess oil can be problematic in composting.
In practical terms, the typical pizza box with some grease stains is fine for compost. The very oily extreme cases may warrant trashing rather than composting.
The cheese question
Beyond grease, there’s the cheese question. Most pizza boxes have some leftover cheese, sauce, or food residue. The rules:
Small amounts of cheese and food residue: Compostable. Commercial composting handles dairy and food residue routinely.
Larger pieces of food still attached: Sometimes worth scraping off before composting. Pull off any whole slices of pepperoni, large pieces of cheese, or significant food chunks. They can either go to compost separately (food waste stream) or stay in the box if your local program accepts mixed loads.
Pizza crusts in the box: Acceptable in most municipal compost programs. Bread, including pizza crust, composts well.
For backyard composters specifically (which I’ll address below), the cheese and pepperoni in pizza boxes is problematic — backyard composting struggles with meat and dairy.
When pizza boxes shouldn’t be composted
A few specific situations where you shouldn’t compost pizza boxes even where the program normally accepts them:
Boxes with non-paper components. Some pizza chains use boxes with plastic liners or plastic inserts (for crispness control). These have non-compostable components. Look for the liner or insert; remove it before composting.
Boxes with glossy coatings. Some pizza boxes have a clay or plastic coating for visual quality. These don’t compost as cleanly. If the box has a noticeably glossy or coated surface, check with your program.
Boxes with significant non-pizza waste mixed in. If you’ve used the pizza box to collect other waste (napkins with non-compostable elements, plastic cups, etc.), separate those before composting.
Boxes from before grease/cheese contamination: Clean cardboard boxes that haven’t been used for pizza are also fine to compost. The grease question doesn’t apply to fresh boxes.
Backyard composting and pizza boxes
For backyard composters specifically, pizza boxes are trickier. The issues:
Grease is harder to handle. A backyard pile at 80-120°F doesn’t process grease as efficiently as a commercial windrow at 130-150°F.
Meat and dairy attract pests. Cheese and pepperoni residue in pizza boxes can attract rodents and flies to a backyard pile.
Slower breakdown. A pizza box in a backyard pile may take 6-12 months to fully break down versus 30-90 days in commercial composting.
The practical recommendation for backyard composters:
- Lightly greasy clean boxes: Can be backyard composted if torn into smaller pieces (4-6 inch pieces) and well-mixed with other materials.
- Moderately greasy or food-residue-heavy boxes: Better in commercial compost or trash.
- Heavily greasy boxes: Trash.
For backyard composters who only have a small pile, the marginal benefit of composting one greasy pizza box doesn’t outweigh the pest attraction risk. Save the boxes for commercial composting if available.
What to do if your area doesn’t accept them
If you’re in an area where commercial composting doesn’t accept pizza boxes, the options:
Recycle the unstained portions. Tear off the clean portions (typically the top of the box, sometimes the bottom corners) and recycle the cardboard. The greasy portions go to trash.
Trash the whole box. If separating clean from greasy is impractical, the whole box goes to trash. Pizza boxes in landfill don’t compost meaningfully (landfills are anaerobic), but the environmental impact is modest.
Find a different compost option. Some communities have drop-off compost programs at farmers’ markets or community centers that accept pizza boxes even if municipal pickup doesn’t. Check.
The path of “compost everywhere you can, trash where you can’t, recycle where possible” is the realistic approach.
What to do with the partial leftovers
A common scenario: you’ve finished a pizza but have a few slices left in the box. The leftover situation:
Leftover pizza for the fridge: Transfer to a non-compostable container (Tupperware, glass) and refrigerate. The compostable pizza box is meant for delivery transit, not for refrigeration storage.
Pizza crust scraps to compost: Some people eat only the toppings and leave the crusts. The crusts can go to compost directly — they’re bread and compost well.
A whole half-pizza going to fridge: Transfer to a sealed container. The box goes to compost stream after.
The empty pizza box (after the leftovers are stored) is what goes to compost.
How pizza box composting actually works at the facility
For curiosity, what actually happens to a pizza box in commercial composting:
- The box arrives at the facility, mixed in with other organic waste
- Initial sorting removes obvious non-compostables (plastic bags, metal objects)
- The mixed organic waste enters the active composting phase — typically windrows that reach 130-150°F
- Over 30-60 days, microbial activity breaks down the box. The paper degrades first; the grease is processed by the microbial community
- The pile is turned periodically to maintain aeration and ensure uniform breakdown
- After active composting, the material enters a curing phase for another 30-60 days
- Finished compost is screened for any remaining large pieces (typically less than 5mm)
- Final compost is sold or distributed
The box is invisible by the end of the process. The grease has been processed. The cheese residue has been incorporated into the compost.
How to dispose of pizza box properly
A simple decision tree for pizza box disposal:
-
Is the box clean (no grease, no food residue)? Recycle.
-
Is the box lightly to moderately greasy?
– Does your local commercial compost accept pizza boxes? Yes → compost.
– No, but you have a backyard composter? Tear into smaller pieces and mix with browns → backyard compost.
– Neither composting option? Tear off clean portions for recycling, trash the rest. -
Is the box heavily soaked or has significant food residue? Trash.
-
Does the box have plastic inserts or coatings? Remove and trash the inserts. Compost or recycle the cardboard depending on cleanliness.
The plastic insert issue
A specific gotcha worth highlighting: some pizza chains include a plastic insert in the bottom of the pizza box (the small “pizza saver” — that little plastic tripod that prevents the box top from touching the cheese). These need to be removed before composting.
Some chains include other plastic elements — pizza box liners, plastic cup separators, plastic utensils. All need to be separated.
The compostable claim only applies to the cardboard box itself. Other components require separate handling.
A regional pizza box experience
For context, here’s how a couple of different regions handle pizza boxes today:
San Francisco (Recology): Pizza boxes are accepted in the green compost cart along with food waste, paper towels, and yard waste. Grease level not really discussed because the program is lenient. Result: nearly all pizza boxes in SF go to commercial composting.
Suburban Pennsylvania: Pizza boxes go in regular trash. The local solid waste authority doesn’t have a robust organic waste collection program. Result: pizza boxes in landfill.
Chicago (city program): Pizza boxes accepted in the city compost program. Program coverage is patchy — not all neighborhoods have collection. Where available, the pizza boxes go to compost.
Rural Montana: No municipal compost program. Pizza boxes go to trash, sometimes to backyard composting for households that have piles. Backyard composting limitations as discussed.
The regional variation reflects the broader patchwork of US composting infrastructure. The trend is toward more programs accepting pizza boxes, but the trend hasn’t reached everywhere yet.
The marketing question
For pizza chains thinking about how to communicate the compostability of their boxes:
Be specific about the box construction. “Our pizza box is made from FSC-certified recycled cardboard with no plastic liner. It can be composted in any municipal commercial composting program that accepts food-contaminated cardboard.”
Don’t overpromise backyard compostability. Standard pizza boxes don’t compost cleanly in backyard piles. The compostability claim is for commercial composting.
Educate customers on disposal. Some pizza chains include disposal instructions on the box itself. “Compost where available, recycle the clean portions where not.”
Coordinate with local composting infrastructure. In areas with strong commercial composting, the pizza chain can highlight the compostable claim. In areas without composting, the claim is less meaningful.
A pizza chain that’s serious about the sustainability story might even consider the bagasse-blend pizza box described in another article in this series — a faster-composting alternative for premium positioning.
The broader takeaway
Pizza boxes are one of those products where the answer to “can I compost it?” has shifted over the past decade. The historical answer was “no, grease contaminates.” The current answer is “yes, most places, with some caveats about grease level.”
For the typical pizza-eating household in 2025, the most practical approach is:
- Check your local compost program’s policy on pizza boxes
- If accepted, put them in the compost (most municipal programs accept them)
- If not accepted, recycle clean portions and trash the rest
- For backyard composters, lightly greasy boxes can work but the marginal benefit is modest
The aggregate impact across the US is meaningful. A typical American household generates 30-50 pizza boxes per year. Diverting most of those from landfill to commercial composting represents real waste reduction at scale.
For deeper reference on what specific composting programs accept, the BioCycle industry publication maintains coverage of municipal organic waste programs across the US, with policy details on what’s accepted at various facilities.
A final practical thought
The pizza box question is one of those where the answer has changed in ways most consumers haven’t noticed. People who decided “I can’t compost pizza boxes” a decade ago may still be operating on that assumption today. They’re not wrong — they’re using outdated information.
If you’ve been throwing pizza boxes in the trash and you live in an area with municipal commercial composting, check whether you can shift them to the green bin. Many people can; many people don’t know they can.
For pizza-eating households trying to do better on waste, this is one of the easier wins. The boxes go to a different bin. The composting happens at the facility. The cumulative diversion across many households over many years adds up to meaningful waste reduction.
So can you compost pizza boxes? In most US cities, yes. The grease, the cheese, the residue — all are okay in commercial composting. The pizza box that ends up in compost rather than landfill is doing more environmental good than the marketing materials of any food packaging brand. It’s the simple structural choice that benefits from being made consistently.
Pizza tonight? Eat the pizza, save the leftovers, put the box in the compost bin. It works. Most places.