Why Curbside Composting Programs Have Rules About Bags
Curbside composting programs compostable bags acceptance is one of the most common sources of confusion for households trying to do the right thing. You collect your food scraps, drop them in a certified compostable bag, and set it at the curb, only to find out your city doesn't accept it. Or maybe your city does accept it, but only bags with specific certifications. The rules vary significantly from one municipality to the next, and understanding why helps you navigate them without wasting time or contaminating a load.
The reason programs have strict bag policies comes down to how composting facilities operate. Industrial composting facilities run on tight timelines and controlled conditions. They need materials to break down predictably, and a bag that doesn't meet the right certification can survive the process, leaving plastic fragments in the finished compost. Contamination from non-certified bags has caused real problems at facilities, damaged compost quality, and in some cases led programs to ban bags entirely.
So when a facility says it accepts certified compostable bags, it means bags that have been independently tested and verified, not bags that just look the part or carry vague marketing language.
What Certification Actually Matters for Curbside Programs
BPI certification is the standard most US municipal composting programs rely on when deciding which bags to allow. BPI, the Biodegradable Products Institute, requires independent third-party laboratory testing before a product can carry its logo. It is not a self-declared claim. A manufacturer cannot simply state their bag is BPI certified. The product must pass testing and meet ASTM D6400 compostability standards, which require 90% disintegration within 84 days under industrial composting conditions, which include temperatures of 55 to 60 degrees Celsius, controlled humidity, and active microbial activity.
GreeneWrap bags carry both BPI certification and TUV Austria certification, and meet ASTM D6400 (USA) and EN 13432 (EU) compostability standards. That combination of certifications covers the requirements for virtually every US municipal composting program that accepts certified compostable bags.
When you check your local program's requirements, look specifically for BPI certification as the qualifying standard. If a program lists ASTM D6400 compliance as acceptable, BPI-certified bags satisfy that requirement. If the program simply says "certified compostable," BPI certification is the recognized verification in the US context.
Cities and Regions Where Curbside Composting Is Widely Available
Curbside composting programs have expanded considerably across the US, but availability and rules vary by city, county, and in some cases by neighborhood. Here is a general picture of where programs are well established and what they typically accept.
San Francisco and the Bay Area
San Francisco has one of the longest-running mandatory composting programs in the country. The city requires residents to separate food scraps and food-soiled paper into the green bin. Certified compostable bags are accepted and encouraged for lining kitchen compost bins, but the bags must carry accepted certification. SF Environment and Recology have both historically directed residents toward BPI-certified bags. Los Angeles runs a separate organics recycling program under its SB 1383 compliance efforts, with similar requirements for certified compostable liners.
New York City
New York City expanded its composting program significantly in recent years, moving toward a citywide mandatory system. NYC's program accepts food scraps and food-soiled paper in the brown bin. The city's guidelines have specified BPI-certified compostable bags as acceptable liners. As the program continues to scale, checking the NYC Department of Sanitation website for current bag requirements is the most reliable step, since guidelines can update as the program grows.
Seattle
Seattle has required food and yard waste composting for years through Seattle Public Utilities. The program accepts certified compostable bags as liners for food scraps. Seattle's guidelines align with BPI certification requirements. The city uses the compost produced through its program for agriculture and landscaping, which is part of why bag certification matters so much. Non-certified bags can leave residue in finished compost.
Portland
Portland's curbside composting program through Metro and individual city haulers accepts food scraps year-round. Portland accepts certified compostable bags and specifically references BPI certification as the qualifying standard. Residents use compostable bags to line their kitchen collectors before transferring to the green cart.
Denver, Austin, and Other Expanding Programs
Denver launched a compost program that has expanded its reach over recent years. Austin's composting program through Austin Resource Recovery accepts food scraps and food-soiled items. Both cities, like most programs expanding under state organics diversion requirements, accept BPI-certified compostable bags. Chicago, Boston, and Minneapolis all have either citywide or district-level composting options, some through city programs and some through private haulers operating in specific zip codes.
How to Check Whether Your City Accepts Compostable Bags
The fastest, most accurate way to confirm your program's rules is to go directly to the source. Here is a practical checklist for finding the right information.
- Search your city or county's waste management website. Look for terms like "organics recycling," "food waste program," or "green bin guidelines." Most programs publish an accepted materials list.
- Look for specific certification language. If the program lists "BPI certified" or "ASTM D6400 compliant" as requirements, you know exactly what to look for on a bag's packaging.
- Check if your hauler has its own rules. In areas where private haulers run composting services, the hauler's requirements may differ from city guidelines. Check the hauler's website or call them directly.
- Use the BPI program locator. BPI maintains a directory of composting facilities and programs that accept BPI-certified products. It is a useful starting point for confirming your area's requirements.
- Contact your city's waste or sustainability department directly. A quick email or phone call confirms current policy and avoids outdated information from third-party sources.
- Check for recent updates. Programs change their accepted materials lists as facilities update their equipment and processes. If you last checked two years ago, it is worth confirming again.
What Happens If Your Program Doesn't Accept Bags
Some curbside programs accept food scraps but require them to be placed directly in the bin without a liner. Others ban bags entirely due to past contamination issues from non-certified products. If your program falls into this category, you have a few practical options.
First, you can still use compostable bags to collect scraps in your kitchen, then empty the contents directly into your curbside bin and compost the bag separately through a home compost bin. Second, if you have access to a backyard compost bin, certified compostable bags with TUV OK Compost HOME certification are designed to break down in ambient home composting conditions within 180 days. Third, many cities have drop-off composting locations at farmers markets, community gardens, or transfer stations that may accept certified compostable bags even if curbside pickup does not.
The fact that a program doesn't accept bags doesn't mean the bags are the wrong product. It often reflects the facility's specific equipment and processing timeline rather than a judgment on the bag's quality or certification.
A Note on PFAS and Why It Matters for Your Program
California's AB 1201 specifically prohibits products containing PFAS from carrying a compostable label. This reflects a real problem in the composting industry. Some compostable fiber products, including plates, bowls, and food service packaging, have historically contained PFAS as a grease barrier. PFAS does not break down in composting and can contaminate finished compost and the farmland it is applied to.
This is worth knowing when choosing bags for your composting program. GreeneWrap products are PFAS free and fluorine free, confirmed by the manufacturer. Some compostable products from other brands may contain PFAS, so checking certification is important. BPI no longer certifies compostable fiber products with intentionally added fluorine, which is a meaningful shift in the industry standard.
When you use compostable food bags that are both BPI certified and confirmed PFAS free, you are not adding any harmful chemistry to the composting stream. That matters both for the facility's compost quality and for the soil where it ends up.
Getting Curbside Composting Right From Day One
Starting a curbside composting habit is straightforward once you have confirmed your program's requirements. A few practical points to keep in mind.
Empty your kitchen compost collector into the curbside bin frequently, ideally every day or two if you are collecting wet food scraps. Moisture accelerates the breakdown of certified compostable bags, so keeping wet waste in a bag for more than one to two days can weaken it. That is true of all certified compostable bags, not just one brand.
Store unused bags in a cool, dry place and use them within 12 months of purchase. Compostable bags are stable under normal indoor storage conditions, but heat and humidity over time will start the breakdown process before you want it to.
Sharp objects including broken shells, bones, or hard food waste can puncture compostable bags, just as they can puncture any bag. Keep that in mind when collecting food scraps with harder materials.
Curbside composting programs are one of the most direct ways households can reduce organic waste going to landfill, where biodegradation occurs significantly slower due to limited oxygen and moisture. Using certified compostable bags correctly, checking your local program's requirements, and choosing bags with verified certifications like BPI makes the system work better for everyone, including the farms and gardens that benefit from quality finished compost.
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