Bioplastics
Biodegradable, compostable, PCR, and PHA are not interchangeable. A buyer’s decoder of what each bioplastic term legally means and which certification proves it.
Bioplastics
Biodegradable vs compostable, decoded for buyers.
These four terms get used interchangeably in vendor marketing, and that is a procurement trap. Biodegradable, compostable, PCR, and PHA describe different things: one is a vague property with no single standard, one is a certified breakdown pathway, one is a recycled-content category, and one is a specific polymer family. A buyer who treats them as synonyms can select a material that fails a regulatory claim audit or an Extended Producer Responsibility (EPR) report. This guide decodes what each term legally means and which certification, if any, proves it.
When you need a material that matches your actual claim, you can request a quote and our desk will source against the right certification.
Biodegradable: the term with no single standard
“Biodegradable” means a material will break down through biological activity, but on its own it specifies no timeframe, no environment, and no endpoint. There is no single certification that proves a generic “biodegradable” claim. Test methods like ASTM D5511 measure anaerobic biodegradation in a simulated landfill digester, but D5511 is a test method, not a certification, and there is no “D5511 certified” mark. The US FTC Green Guides flag bare biodegradable claims as potentially deceptive when the product is unlikely to encounter the test conditions in real disposal, and California SB 343 prohibits “biodegradable” labeling on landfill-bound items that rely solely on D5511 evidence.
Buyer takeaway: a vendor offering “biodegradable” without naming a compostability standard is offering a marketing claim, not a compliance credential.
Compostable: a certified breakdown pathway
“Compostable” is a defined, certifiable claim, but only against a named standard and disposal environment. The standards are not interchangeable:
- ASTM D6400 (US, industrial compost) and ASTM D6868 (US, coated paper, industrial compost).
- EN 13432 (EU, industrial compost), marked OK Compost INDUSTRIAL by TUV Austria.
- OK Compost HOME (backyard compost), a stricter and distinct certification.
- BPI Certified and CMA Certified as the recognized US third-party labels, with CMA adding real compost-facility field validation.
A product certified to OK Compost HOME is not certified for industrial facilities, and most PLA cannot meet HOME because it needs around 58 degrees C to break down. Require the standard, the body, and the certificate number.
PCR: a recycled-content category, not a breakdown property
PCR stands for post-consumer recycled content. It describes where the material’s feedstock came from (recovered consumer waste), not how it breaks down. PCR content is verified to a recycled-content standard such as ISO 14021 by a third party (for example, UL Environment or SCS Global). PCR is increasingly a compliance line item: California SB 54 requires 30 percent recycled plastic content by 2028. A material can be high-PCR and not compostable, or compostable and not PCR; the two claims are independent.
PHA: a specific polymer family
PHA (polyhydroxyalkanoates) is a microbially produced polymer family, distinct from PLA (polylactic acid). The practical difference for buyers is end-of-life: PHA can be home- and even marine-compostable depending on grade, whereas most PLA requires industrial-compost conditions. PHA carries a price premium and is the right choice when the disposal pathway is uncontrolled. Naming the polymer (PHA vs PLA vs starch blend) is part of the spec, not a detail.
Why cert specificity is the buyer’s defense
The recurring problem in bioplastic sourcing is vendors who cite a certification family without naming the level. “Vincotte certified” (Vincotte is now TUV Austria) could mean OK Compost HOME, OK Compost INDUSTRIAL, or OK Biobased, which prove three different things. For a procurement-grade claim, require the exact standard, the certifying body, and the certificate number, and confirm it resolves in the public database.
A quick decision guide
- Need a verifiable end-of-life claim? Require a named compostability certification (D6400, EN 13432, or OK Compost HOME), not “biodegradable.”
- Subject to EPR recycled-content mandates? Specify PCR percentage with ISO 14021 verification.
- Disposal pathway uncontrolled (consumer, agricultural, marine)? Consider PHA, certified for the actual environment.
- Making a biobased-content claim? That is USDA BioPreferred (ASTM D6866), separate from compostability.
How ECS helps
ECS is a vendor-neutral routing partner. We translate your real claim (compostable for an industrial stream, high-PCR for an EPR report, home-compostable PHA for consumer disposal) into a procurement-grade spec, run the RFQ across qualified suppliers, and verify every certificate number before recommending a material. You get a claim you can defend, not a term you have to hope holds up.
Request a quote with your format, claim, and markets to start.
Questions buyers ask
Frequently asked questions.
Is biodegradable the same as compostable?
No. Compostable is a certified breakdown under defined conditions; biodegradable is a vague property with no single standard and is flagged by the FTC Green Guides when used without a named certification.
What is PCR plastic?
PCR is post-consumer recycled content, describing the feedstock origin, not the breakdown pathway. It is verified to ISO 14021 and is often required by EPR programs.
What is the difference between PHA and PLA?
Both are bioplastics, but PHA can be home- and marine-compostable depending on grade, while most PLA needs industrial-compost conditions around 58 degrees C. PHA costs more.
Why is “Vincotte certified” not enough?
Vincotte (now TUV Austria) issues several distinct marks, OK Compost HOME, OK Compost INDUSTRIAL, and OK Biobased, which prove different things. Require the exact standard and certificate number.
Can a material be both compostable and high-PCR?
The two claims are independent. A material can be one, both, or neither. Specify each requirement separately and verify each certification.
Keep reading
Related guides and pillars.
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