Shaoxing, Zhejiang, China - August 24, 2026 - Three terms buyers must stop using interchangeably:
- Compostable has a closed, auditable definition: ≥90% biodegradation, ≥90% disintegration, and ecotoxicity pass per EN 13432 (58°C industrial composting) or ASTM D6400. Without third-party certification to one of these standards, the claim is not legal in the EU.
- Biodegradable has no closed definition in most jurisdictions — it only requires that a material eventually breaks down via microbial action, with no threshold for timeframe, no required ecotoxicity, and no heavy-metal limit. The EU SUPP recast is moving to restrict the term.
- Degradable (especially "oxo-degradable") means fragmentation via oxidation, not biodegradation — it produces microplastic, not compost. The EU banned oxo-degradable plastics in 2021 (Directive (EU) 2019/904, effect 3 July 2021).
- Picking the wrong term costs money. A "biodegradable" bag that fails disintegration testing in actual compost costs the brand its sustainability report, and an oxo-degradable product now triggers EU enforcement penalties.
- The right procurement question is not "is it biodegradable?" but "which certification body, which standard, and which certificate number?"
For fifteen years I have watched packaging buyers use the words compostable, biodegradable, and degradable as if they were synonyms. They are not. Because the three terms are defined under three different regulatory frameworks with three different test protocols and three different legal consequences, mixing them up is not a vocabulary mistake — it is a procurement risk that can quietly void a sustainability report, trigger an EU enforcement penalty, or land a product on a regulator's banned list.
This article is the post-mortem of every sustainability claim I have ever had to reverse-engineer for a buyer who came to me too late. We will define each term against the actual regulatory text — EN 13432, ASTM D6400, ISO 17088, plus the EU's 2021 oxo-degradable ban — and then walk through the five procurement questions that turn "biodegradable" into a verifiable certificate number.
Two-sided coated cellulose film — a true compostable packaging substrate, not a biodegradable or degradable one. Image courtesy of Zhejiang Xiade New Material Co., Ltd.The Vocabulary War Most Buyers Lost Without Knowing It Started
"Biodegradable" beats "compostable" in marketing copy because it sounds broader. It is also the term that lets a supplier avoid committing to a test, a threshold, and a certificate. Because the word "biodegradable" carries no closed legal definition in most jurisdictions, a supplier can print it on a polyethylene bag without fear of an enforcement action — even though the bag will sit in a landfill for 200 years without any meaningful microbial breakdown.
The vocabulary war did not start with greenwashing. It started with the legitimate gap between buyers who wanted a single word for "this material is not persistent" and the actual science of how different materials break down. The word "compostable" was created to fill that gap with a definition that could be tested. The word "degradable" was co-opted by the polyolefin industry to describe oxidative fragmentation. "Biodegradable" got stuck in the middle, used correctly by some and abused by others.
The harm is not academic. Because the three terms are defined under three different regulatory frameworks with three different test protocols and three different legal consequences, a buyer who treats them as synonyms will mis-specify a product, mis-quote a sustainability report, and create a documented paper trail that can be used against the brand in regulatory enforcement. The fix is to learn the precise definitions, name the regulatory framework, and demand the certificate number — not the marketing logo.
Compostable: The Only Term With a Closed, Auditable Definition
Compostable is a closed, auditable term. To make a "compostable" claim on packaging in the EU, the material must pass all four EN 13432 tests performed by an accredited third-party laboratory. In the US, the equivalent framework is ASTM D6400 administered through the BPI certification mark. Globally, ISO 17088 is the umbrella standard that EN 13432 and ASTM D6400 align with.
The four tests are non-negotiable, and any one of them can fail a submission independently:
- Chemical characterisation — heavy metals (Pb+Hg+Cd+Cr⁶) below 50 mg/kg combined per dry mass.
- Biodegradation — ≥90% conversion to CO₂ within 6 months per OECD 301B.
- Disintegration — ≥90% of sample passes through a 2 mm mesh within 12 weeks at 58°C, 65% RH.
- Ecotoxicity — no negative effect on plant germination and biomass versus control compost per OECD 208.
Because the four tests are mandatory and the certificate is third-party issued, "compostable" is the only term that survives a procurement audit cleanly. The certificate number is the claim. The mark is decoration.
Biodegradable: The True Meaning, The Common Misuse, and The Regulatory Pushback
Biodegradable describes any material that undergoes microbial breakdown into CO₂, water, and biomass under specific environmental conditions. The term has no closed definition in most jurisdictions, no required timeframe, no required ecotoxicity threshold, and no required heavy-metal limit.
The true scientific meaning is precise: biodegradation is microbial conversion of organic material into CO₂ and biomass. But the legal meaning is loose. Because the term has no threshold, a material that biodegrades 1% in 100 years technically qualifies as "biodegradable" under the broad definition, and a supplier can claim it. That is the regulatory gap the EU is now closing.
The EU SUPP recast (in draft as of 2025, finalisation expected 2026) is moving to restrict the use of "biodegradable" on packaging to materials that meet specific disintegration thresholds within a defined timeframe — essentially importing the EN 13432 framework into the label itself. Because the regulatory pushback is real, a marketing claim of "biodegradable" on packaging today will become a regulatory liability in the EU within 24 months.
For B2B buyers, the implication is clear: any sustainability report that relies on "biodegradable" claims without specifying a standard, a timeframe, and a certificate number is at risk of retrospective correction when the EU regulation finalises.
Degradable (Including Oxo-Degradable): The Term That Survived Greenwashing the Longest
Degradable (especially "oxo-degradable") describes fragmentation via oxidation, heat, or UV light — not microbial breakdown. Oxo-degradable plastics are conventional polyolefins (PE, PP) with a metal-salt additive that triggers oxidative fragmentation. The resulting microplastic fragments are not compost and never biodegrade into CO₂.
The EU banned oxo-degradable plastics across all member states effective 3 July 2021 under Directive (EU) 2019/904 (Single-Use Plastics Directive). The rationale was explicit: oxo-degradable plastics fragment into microplastic that contaminates conventional recycling streams and the environment, and the fragmentation misleads consumers into believing the material is composting when it is actually producing microplastic. Because the EU ban is in force and member states are required to enforce, an oxo-degradable product placed on the EU market today triggers enforcement penalties in every member state.
Outside the EU, the picture is more mixed. Several Latin American and Middle Eastern markets still allow oxo-degradable products, and the term "degradable" is used loosely in many regions. Because the EU has set the precedent and the trend is global, a procurement decision that anchors on "degradable" rather than "compostable" is signing a contract that will need to be re-specified inside the next five years.
The Legal Map: EN 13432, ASTM D6400, ISO 17088, and What Each One Actually Requires
Three standards govern the closed definition of "compostable" globally, and the procurement decision is to match the standard to the target market — not to assume any one of them is sufficient.
Side-by-side: EN 13432 vs ASTM D6400 vs ISO 17088
| Standard |
Region |
Test framework |
Certification body |
Notes |
| EN 13432 |
EU |
4-test protocol (chemical, biodegradation OECD 301B, disintegration 2 mm mesh, ecotoxicity OECD 208) |
TÜV Austria, DIN CERTCO, AIB Vincotte |
Recognised across EU member states; pairs with OK Compost, OK Compost HOME, Seedling marks |
| ASTM D6400 |
US |
Same 4-test framework, US-centric conditions |
BPI (Biodegradable Products Institute) |
Recognised in US states with explicit compostable labelling laws; pairs with BPI mark |
| ISO 17088 |
Global |
4-test framework plus bio-based content obligations |
Various ILAC-accredited bodies |
Umbrella standard; EN 13432 and ASTM D6400 align with it for global acceptance |
Because the three standards are not interchangeable, a product with EN 13432 certification does not automatically carry ASTM D6400, and a product with ISO 17088 certification may not meet EN 13432 if the bio-based content obligation is not satisfied. The procurement decision is to specify which standard is required for the target market, then verify the certificate number in the corresponding live database.
The Procurement Decision: Asking the Right Question for Every End-of-Life Scenario
Choosing compostable, biodegradable, or degradable is not a vocabulary question — it is an end-of-life scenario question. The right term depends on where the material is supposed to end up.
End-of-life scenario → correct term → standard → certification body
| End-of-life scenario |
Correct term |
Minimum standard |
Recommended certification body |
| Industrial composting facility (EU/US/Japan) |
Compostable |
EN 13432 / ASTM D6400 / ISO 17088 |
TÜV Austria / BPI / DIN CERTCO |
| Home backyard compost bin |
Compostable (HOME) |
EN 13432 home variant / TÜV OK Compost HOME |
TÜV Austria (OK Compost HOME) |
| Soil (agricultural mulch, planting) |
Biodegradable in soil (with timeframe) |
ISO 17556 / EN 17033 |
TÜV Austria / DIN CERTCO |
| Freshwater (pod, sachets) |
Biodegradable in water (with timeframe) |
ASTM D6691 / TÜV OK Biodegradable WATER |
TÜV Austria |
| Marine (only where unavoidable) |
Not recommended — prefer prevention |
ASTM D6691 (with explicit timeframe) |
No widely accepted certification |
| Landfill (no specific pathway) |
Degradable is irrelevant |
None |
None |
Because the wrong term misrepresents the end-of-life pathway, the procurement decision must start with the scenario and end with the certificate number. The phrase "biodegradable bag" is procurement-meaningless because it does not tell the buyer where the bag is supposed to break down, in what timeframe, and under what test conditions.
When a Supplier Says 'Biodegradable' — The Five Follow-Up Questions
Every "biodegradable" claim on a supplier datasheet is a procurement pause button. The five questions below are the ones I send to every supplier who sends me a "biodegradable" datasheet without a certificate number.
- What standard is the biodegradability claim issued against? An acceptable answer is a specific named standard (EN 13432, ASTM D6400, ISO 17088, ISO 17556, ASTM D6691). An unacceptable answer is "biodegradable in normal conditions" or "per industry standard."
- Which certification body issued the certificate? Acceptable bodies are ILAC-accredited and named: TÜV Austria, DIN CERTCO, BPI, JBPA, or a national equivalent. An unacceptable answer is "internally tested" or "self-certified."
- What is the certificate number? The certificate number is the only document that proves the claim is real. Request the PDF and the number, then verify in the live database of the certification body.
- What is the timeframe for biodegradation under the named standard? If the supplier cannot specify a timeframe (e.g., "≥90% in 6 months" per EN 13432), the claim is not procurement-grade.
- Does the certificate cover the full product, including the adhesive and any coatings? A certificate for the substrate alone does not cover a finished tape or laminate. The full product must be tested as a finished article.
If a supplier cannot answer all five questions with a verifiable certificate number, the "biodegradable" claim is not procurement-grade evidence. Because the cost of a missed claim is a voided sustainability report, an EU enforcement penalty, or a product recall, the five questions are not optional — they are the minimum procurement standard.
The bottom line is this: because compostable, biodegradable, and degradable are three distinct regulatory frameworks with three different test protocols and three different legal consequences, the procurement decision is to specify the standard, demand the certificate number, and verify in the live database. The vocabulary is the easy part. The certificate number is the hard part, and the only one that matters.
Get the precise EN 13432 / ASTM D6400 definitions for our cellulose film line
We supply the complete standards mapping (EN 13432, ASTM D6400, ISO 17088) for each cellulose film SKU, with the certification body, certificate number, and the most recent audit date. For procurement teams writing or auditing specifications, we also supply a one-page "compostable vs biodegradable vs degradable" cheat sheet templated to your internal supplier questionnaire.
→ Cellulose film product family→ FAQ — common buyer questions on compostability→ Request the standards mapping & quote
Yusheng Yan
Senior Materials Scientist & Technical Director — Zhejiang Xiade New Material Co., Ltd. (XIADE)
"A packaging film that outlasts the product it protects is not a packaging solution — it is a waste problem waiting to happen."
Joined XIADE in 2010, contributing to the R&D of natural cellulose films that meet EU food contact material standards. Our natural cellulose films are biodegradable, insulating, heat-resistant, and anti-static, and serve aerospace, military, medical subcontracting, food subcontracting, craft packaging, tape substrates, and insulation materials. Zhejiang Xiade New Material Co., Ltd. operates from the largest ecological industrial park in Zhejiang, covering 116,700 sqm with a 60,000 sqm building area, and holds ISO 9001:2000 and ISO 14001:2004 certifications as China's largest manufacturer of natural cellulose membranes. I work with medical device and food packaging buyers who need to balance barrier performance, sterilization compatibility, and EU sustainability requirements at industrial scale.
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Frequently Asked QuestionsWhat is the difference between compostable and biodegradable?
Compostable is a closed, auditable term. To be called compostable in the EU, a material must pass all four EN 13432 tests (chemical characterisation, ≥90% biodegradation in 6 months, ≥90% disintegration at 2 mm mesh in 12 weeks, and ecotoxicity per OECD 208). Biodegradable is a non-closed term that only requires eventual microbial breakdown, with no required timeframe, no ecotoxicity threshold, and no heavy-metal limit. The two terms are not interchangeable.
Are oxo-degradable plastics banned in the EU?
Yes. EU Directive 2019/904 (Single-Use Plastics Directive) banned oxo-degradable plastics across all member states effective 3 July 2021. Member states are required to enforce the ban with penalties varying by country. Oxo-degradable plastics were excluded because they fragment into microplastic rather than biodegrade, contaminating conventional recycling streams and the environment.
Is 'biodegradable' a regulated term?
In most jurisdictions, no. The EU SUPP recast (in draft as of 2025, finalisation expected 2026) is moving to restrict the use of 'biodegradable' on packaging to materials that meet specific disintegration thresholds. In the US, the FTC Green Guides discourage unqualified 'biodegradable' claims because no timeframe or test method is implied. Third-party certification to a specific standard (EN 13432, ASTM D6400, ISO 17088) is the procurement-grade evidence that 'biodegradable' claims must be backed by.
What is ASTM D6400?
ASTM D6400 is the US standard for compostable plastics, administered by ASTM International. It specifies the same four-test framework as EN 13432 (chemical, biodegradation, disintegration, ecotoxicity) but uses US-centric test conditions and is paired with the BPI certification mark. ASTM D6400 does not equal EN 13432 — a separate submission is required for each jurisdiction.
What is ISO 17088 and how does it differ from EN 13432?
ISO 17088 is the international standard for compostable plastics, harmonised globally. It specifies the same four-test framework as EN 13432 and ASTM D6400 but focuses on bio-based content requirements in addition to compostability. EN 13432 is the EU implementation; ASTM D6400 is the US implementation. ISO 17088 is the umbrella document that EN 13432 and ASTM D6400 align with for global acceptance.
Can a plastic be biodegradable but not compostable?
Yes. A material that biodegrades over 50 years in soil technically meets the broad definition of biodegradable but does not meet the 6-month biodegradation threshold for compostable. Many traditional bio-based plastics fall into this category — they biodegrade eventually under specific conditions but do not compost in a useful timeframe. This is why "biodegradable" cannot be a procurement specification without a qualifying standard.
Why is 'oxo-degradable' considered greenwashing?
Oxo-degradable plastics are conventional polyolefins (PE, PP) with a metal-salt additive that triggers oxidative fragmentation when exposed to UV light or heat. The material does not biodegrade — it breaks into smaller and smaller plastic fragments that persist in the environment for decades. The EU banned oxo-degradable products in 2021 precisely because the fragmentation misleads consumers into thinking the material is composting, when it is actually producing microplastic.
What is the right procurement question to ask a supplier about compostability?
Ask: "Which certification body? Which standard? Which certificate number?" Acceptable answers are: TÜV Austria OK Compost, DIN CERTCO, BPI (US), JBPA GreenPla (Japan), or any ILAC-accredited certification body. The certificate number must be verifiable in the certifying body's live database. Self-declarations and "biodegradable" without a standard are not procurement-grade evidence.
About Us
ZHEJIANG XIADE NEW MATERIAL CO.,LTD. is a professional global export leader and international business window under Shaoxing Kede New Materials Co., Ltd. We rely on the excellent research and development capabilities and large-scale production base of the Kod factory, and are committed to promoting high-quality natural cellulose membrane products to the global market.
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