Biodegradable Straw Claims: B2B Compliance Guide

Biodegradable Straw Compliance Guide: How Buyers Verify Claims

To verify biodegradable straw claims before sourcing, request three documents from every supplier: the certificate number issued by an accredited body (BPI, TÜV Austria, DIN CERTCO), the original laboratory test report showing results against EN 13432, ASTM D6400 or ISO 17088, and a written resin declaration naming the exact polymer and additives. As of 2026, “biodegradable” remains an unregulated marketing word in most markets — only “compostable” is tied to a testable standard. This biodegradable straw compliance guide walks through the documents that hold up in an audit.

Which Compostable Straw Certifications Actually Matter

Four certification systems cover the straws sold into foodservice today. Anything else — including self-issued PDFs and “100% eco” badges — carries no legal weight.

• EN 13432 (Europe) — requires 90% disintegration within 12 weeks, 90% biodegradation within 6 months at 58°C, plus ecotoxicity and heavy-metal limits. This is the reference standard behind the EU Single-Use Plastics Directive (EU) 2019/904.
• ASTM D6400 (United States) — the US equivalent, with the same 90%/90% thresholds inside a 180-day window.
• BPI Certified — the Biodegradable Products Institute verifies ASTM D6400 compliance for North America. Most US foodservice buyers and commercial composters accept BPI and little else.
• TÜV Austria OK Compost — two grades: INDUSTRIAL (EN 13432) and HOME, which tests degradation at ambient 20–30°C over roughly 12 months. OK Compost HOME is the harder and more valuable claim.

In practice, a straw carrying EN 13432 plus OK Compost HOME or BPI satisfies nearly every procurement question in Europe and North America. For the full document set required per market, see our compostable straw certification requirements buyer guide.

How to Read EN 13432 Straw Testing Reports

A certificate alone is not proof. The test report behind it is where greenwashing hides. Work through these five checks in order:

• 1. Match the certificate holder to the factory. If the certificate belongs to a trading company you have never audited, the claim is effectively unverified.
• 2. Confirm the tested item matches your order. Reports list dimensions, colour and resin. A 6 mm straw certificate does not cover a 12 mm boba straw.
• 3. Check the issue date. Reports older than five years, or issued before a resin change, should be re-issued.
• 4. Read all three test sections. Disintegration, biodegradation and ecotoxicity must each pass — a “pass” stamp on page one is not enough.
• 5. Verify the laboratory holds ISO/IEC 17025 accreditation and is named in the report footer.

Greenwashing Red Flags in Compostable Straw Claims

Certain phrases reliably signal a weak claim. Treat each as a trigger for documentation requests:

• “100% biodegradable” with no standard number attached.
• “Oxo-degradable,” “bio-based” or “plant-based” used as a synonym for compostable — bio-based content says nothing about degradation.
• Certificates naming a competitor, a distributor, or no legal entity at all.
• Claims of ocean or soil degradation with no test method cited.
• Reluctance to disclose the resin supplier or batch-level test data.

Ask suppliers four questions in writing: Which standard was tested? What is the certificate number and expiry date? Does the certificate cover this exact SKU? Will you accept a third-party retest at our cost? Suppliers holding genuine certification answer all four within one business day. For cost and MOQ benchmarks on certified lines, see biodegradable straw sourcing: MOQ, cost and certifications.

FAQ: Biodegradable Straw Compliance Guide

Q: Is “biodegradable” the same as “compostable” for straws?

A: No. Compostable means the product has passed a defined standard such as EN 13432 or ASTM D6400 within a set timeframe. Biodegradable has no agreed timeframe or test method, so it cannot be enforced or independently verified.

Q: How much does compostable straw certification cost?

A: Initial certification typically runs €3,000–€8,000 per product family, plus annual surveillance fees. Certificates are usually valid three to five years, and re-testing is required after any resin or formulation change.

Q: Do I need BPI certification if I already have EN 13432?

A: Yes, if you sell into the United States or Canada. BPI verifies ASTM D6400 and is the claim most North American composters and foodservice operators accept; EN 13432 alone is rarely recognised there.

Conclusion

A biodegradable straw compliance guide ultimately reduces to one rule: certification, not copywriting, protects a buyer from greenwashing liability. Build your specification around EN 13432, ASTM D6400, BPI or OK Compost HOME, keep the certificate number and test report on file, and re-verify whenever the resin changes. ZTstraw has manufactured certified compostable straws and tableware for 30 years and exports to more than 30 countries, supplying test documentation with every order. Send your specification to sales@ztstraw.com or browse the range at ztstraw.com/products.

Not sure how your spec maps to these standards? Tell us the target market and SKU, and our factory team will walk you through the documents to request for your market — no obligation.