Biodegradable Straw Certification: Marine vs Compost

Do biodegradable straws actually break down in the ocean? Not in any timeframe you can claim. As of 2026, biodegradable straw certification refers to documented third-party verification against a named end-of-life standard: EN 13432 or ASTM D6400 for industrial composting, OK Compost HOME for backyard compost, and ASTM D6691 or TÜV OK biodegradable MARINE for seawater. Without a test report tied to one specific disposal scenario, “biodegradable” is an unverified marketing word.

The gap between that wording and reality was documented in January 2024, when Lab Manager reported a study finding that “biodegradable” straws persist in the ocean for 8–20 months (Lab Manager). Eight to twenty months is not marine degradation; it is slow fragmentation with an unmeasured endpoint.

What the 8–20 Month Ocean Study Changes for Buyers

The material science did not change. The burden of proof did. A straw described as biodegradable with no disposal scenario attached now reads as a generic environmental claim — the exact category regulators in Brussels and Washington are targeting.

EN 13432 requires 90% disintegration within 12 weeks and 90% biodegradation within six months inside an industrial composting facility running at 58–60°C. ASTM D6400 sets comparable parameters. Neither standard tests seawater, and neither supports an ocean claim. Marine standards — ASTM D6691 and TÜV OK biodegradable MARINE — use seawater inoculum and separate protocols, and very few straw factories hold them.

That is the reframe: this is no longer a materials argument about PLA versus paper versus bamboo. It is an evidence argument about which certificate covers which end-of-life.

Match the Certification to the Disposal Scenario

Read the table as a contract, not a menu. A supplier who cannot name the row your product will actually land in is guessing.

Wording Claims That Survive EU and US Scrutiny

Label language is now regulated. The EU Empowering Consumers Directive (EU) 2024/825 applies from 27 September 2026 and bans generic claims such as “biodegradable” or “eco-friendly” without substantiation, while the Green Claims Directive adds the verification methodology. In the US, the FTC Green Guides require competent and reliable scientific evidence and treat unqualified degradability claims as deceptive unless degradation occurs within one year of customary disposal.

Practical rules for on-pack and menu copy:

• Name both the standard and the environment: “Certified industrially compostable to EN 13432.”
• Never run “ocean-degradable,” “100% biodegradable” or “eco-friendly” as standalone claims.
• Attach the condition: “in industrial composting facilities where available.”
• Keep certificate PDFs on file and link them by QR code at the point of sale.

For the full standards mapping, see our biodegradable straw certification requirements guide and the comparison of BPI vs EN 13432.

6-Question RFQ Checklist for Any Straw Supplier

1. Which exact standard is this SKU certified to — EN 13432, ASTM D6400, OK Compost HOME, ASTM D6691 or TÜV OK biodegradable MARINE — and what is the certificate number and issuing body?
2. Can you send the full test report, not just the certificate, showing the tested article matches my dimensions and grade?
3. Which disposal environment does that certificate cover, and which environments does it explicitly exclude?
4. What is your MOQ for certified SKUs, and does certification extend to custom lengths, diameters and printed wraps?
5. Who pays annual surveillance and renewal, and will you notify me in writing if certification lapses?
6. What exact on-pack wording do you recommend for my market, and can you supply a compliance letter to support it?

FAQ

Q: Is PLA an ocean-degradable straw material?
A: No. PLA is certified compostable under EN 13432 and ASTM D6400 in industrial conditions at 58–60°C. In seawater it behaves like conventional plastic over practical timeframes. No marine certificate means no ocean claim.

Q: What is the difference between biodegradable and compostable on a straw?
A: “Biodegradable” only means microorganisms can break a material down — no timeframe, no environment specified. “Compostable” means it meets a defined standard, such as EN 13432’s 90% disintegration within 12 weeks and 90% biodegradation within six months, leaving non-toxic compost.

Q: Which certification should a US foodservice buyer request?
A: ASTM D6400 plus a BPI listing for industrial composting. Add OK Compost HOME only if you are telling customers to compost the straw at home.

Conclusion

No straw — PLA, paper or bamboo — is ocean-degradable without a marine-specific test report, and that single fact should reset every supplier conversation you have. Ask for certificate numbers, match them to your real disposal scenario, and write claims the EU and FTC will accept. ZTstraw has manufactured straws and tableware for 30 years and exports to 30+ countries; our team supplies certificate copies, test reports and recommended on-pack wording with every quotation. Email sales@ztstraw.com or browse the range at ztstraw.com/products.