The word "compostable" appears on packaging all the time. On cups, containers, food service trays, and shipping materials. But when you ask the question "Will this actually compost in my local facility?" the answer is often vague. That is because the word "compostable" is unregulated marketing unless it is backed by a specific certification standard. This matters for procurement teams because buying unverified compostable packaging does not reduce landfill impact. It just shifts the cost and the problem downstream.
This guide walks you through the certification standards that actually mean something. You will learn the difference between compostable, biodegradable, and recyclable. You will understand what ASTM D6400 and D6868 test for. You will learn what BPI certification means and why it matters to commercial composters. And you will learn to spot greenwashing red flags in supplier claims.
Compostable vs. Biodegradable vs. Recyclable
Start with definitions. These words are not interchangeable, and suppliers know this. They use them loosely because consumers often do not know the difference.
Biodegradable
This is almost meaningless. Everything biodegrades eventually, given enough time and the right conditions. A plastic bag can technically biodegrade in a landfill in hundreds of years. The word "biodegradable" on packaging is not regulated by any federal standard in the U.S. It is marketing. Avoid packaging described only as "biodegradable" unless it also carries a certified standard.
Compostable
Compostable means the material breaks down within a specific timeframe under specific conditions. ASTM D6400 specifies industrial composting conditions. EN 13432 specifies European composting conditions. BPI certification means it passes ASTM D6400 testing and a third party has verified it. Compostable packaging must complete 90 percent disintegration in 180 days under controlled conditions and pass ecotoxicity testing.
Recyclable
Recyclable means it can be processed through your local curbside or drop-off recycling program. But "recyclable" is only true if your local facility accepts that material type. A plastic container may be technically recyclable but if your municipality does not have the processing infrastructure, it ends up in landfill. Always verify your local recycling program accepts the material before buying recyclable products.
ASTM D6400 and D6868: The U.S. Standards
ASTM D6400 is the primary U.S. standard for industrially compostable plastic materials. It defines the testing conditions and acceptance criteria. If a supplier claims their product is compostable and sells in the U.S., they should be able to provide ASTM D6400 test data. Here is what this standard actually tests for.
Disintegration Testing
The material must disintegrate into fragments smaller than 2 mm at a rate of 90 percent or more within 180 days in a controlled composting environment. This is the core test. If your material does not meet 90 percent disintegration in 180 days, it fails.
Biodegradation Testing
The material must show 90 percent biodegradation in 180 days. Disintegration is not the same as biodegradation. A material can fall apart (disintegrate) but not fully convert to CO2, methane, and water (biodegrade). ASTM D6400 tests both.
Ecotoxicity Testing
The resulting compost must pass toxicity tests. If the material breaks down but leaves behind toxic residue that harms plants or soil organisms, it fails. This prevents suppliers from adding heavy metals or chemicals to speed decomposition.
Heavy Metal Testing
Maximum allowable levels for mercury, lead, cadmium, and chromium are defined. If your "compostable" food container contains heavy metals, it fails and should never reach a commercial composting facility.
ASTM D6868 is a companion standard that covers coatings and additives on compostable substrates. For example, if you have compostable paper cups with a compostable coating inside, the coating must meet D6868. This prevents manufacturers from slapping a compostable label on a cup with a non-compostable plastic interior.
BPI Certification: The Industry Benchmark
BPI stands for Biodegradable Products Institute. It is a third-party certifier. When a manufacturer runs ASTM D6400 tests, the results come from a lab. But the BPI adds a layer of verification. They audit the manufacturer, verify test results, and maintain a public database of certified products. Commercial composters trust BPI certification because it is the most recognized mark for compostable products in the U.S.
If you are buying compostable packaging for a food service operation and you plan to send waste to a commercial composting facility, that facility will almost certainly accept only BPI-certified products. Many commercial facilities reject non-BPI certified compostable items because they cannot verify the claim. This is a hard boundary for procurement teams. If a supplier sells you "ASTM D6400 compliant" packaging but it is not BPI certified, commercial composting facilities may reject it, and your waste goes to landfill anyway.
You can verify BPI certification on the BPI website. Every certified product is listed with a BPI number. If a supplier gives you a BPI number, check it. Do not accept "We are BPI certified" without a number and independent verification.
EN 13432: The European Standard
EN 13432 is the European equivalent of ASTM D6400. It defines compostability for European industrial composting facilities. If you are sourcing packaging from European suppliers or selling into European markets, EN 13432 is the relevant standard. It is slightly more stringent than ASTM D6400 on some metrics, particularly regarding biodegradation rates and ecotoxicity testing. If your packaging is EN 13432 certified, it is also likely compliant with ASTM D6400, but the reverse is not always true.
Greenwashing Red Flags in Procurement
When evaluating compostable packaging suppliers, watch for these specific warning signs. Greenwashing is common in this category because consumers care about sustainability but often lack the expertise to verify claims.
Red Flag: "Biodegradable" Without Certification
Do not buy packaging labeled only as "biodegradable." Require BPI certification (ASTM D6400 tested and verified) or EN 13432 certification. Without certification, the claim is meaningless.
Red Flag: "Plant-Based" Without Composting Certification
Plant-based materials can sit in a landfill for decades without breaking down. "Plant-based" is not the same as "compostable." Verify that plant-based products are also BPI certified or ASTM D6400 tested.
Red Flag: "Eco-Friendly" as a Standalone Claim
This is completely unregulated. It can mean anything. Require specific certification standards. Ask the supplier to name the standard and provide test data.
Red Flag: Expired or Unverifiable BPI Numbers
If a supplier gives you a BPI number, verify it on the BPI website (www.bpiworld.org). If it is not listed or the listing is expired, the product is not currently certified. Do not buy it.
Red Flag: "Home Compostable" Without Industrial Certification
"Home compostable" is different from "industrially compostable." Home compost operates at lower temperatures and may not break down the material. If your operation uses commercial composting, require industrial compostable certification, not home compostable.
What Northgate Verifies
Northgate Procurement partners only with suppliers who provide verified sustainability certifications. For compostable packaging, we verify BPI certification numbers, audit ASTM D6400 test reports, and confirm that products match the specification your operation actually needs. We do not use the word "compostable" unless the product carries third-party certification. This approach protects your operation from greenwashing and ensures that when you claim sustainability to your partners, the claim is backed by science and audit, not marketing.
Source Verified, Certified Compostable Packaging
Northgate Procurement sources compostable cups, containers, and food service packaging with verified BPI certification or ASTM D6400 testing. We verify every claim and provide test documentation. Tell us your volume, format, and composting partner.
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