ASTM D6400 vs EN 13432: Compostable Packaging Standards Compared

What Are ASTM D6400 and EN 13432?

ASTM D6400 is the standard specification for labeling plastics designed to be aerobically composted in municipal or industrial facilities, developed by ASTM International. EN 13432 is the European standard for packaging recoverable through composting and biodegradation, published by the European Committee for Standardization. Both define the requirements for materials to claim 'compostable' in their respective markets—but they are not identical.

Think of them as two gatekeepers with similar goals but different rulebooks. ASTM D6400 governs compostability claims in the US, Canada, and parts of Asia, while EN 13432 is the benchmark for the EU, UK (post-Brexit), and many other countries. If you sell bagasse clamshells or PLA cutlery globally, you’ll likely need both certifications to avoid market access issues.

Our factory produces ASTM D6400-certified PLA cold cups and EN 13432-certified kraft paper hot cups. We’ve seen firsthand how a mismatch can block a shipment—a US buyer once rejected a container of European-certified cups because the certification body wasn’t recognized by their retailer. That’s a costly lesson.

How Do the Biodegradation Criteria Differ Between ASTM D6400 and EN 13432?

Both standards require at least 90% of the organic carbon to convert to CO2 within 180 days under industrial composting conditions (58°C, high humidity, active microbial population). But the devil is in the test methods. ASTM D6400 references ASTM D5338 for aerobic biodegradation, while EN 13432 references ISO 14855 or ISO 16929. The test duration is the same—180 days—but the acceptable threshold for disintegration differs.

EN 13432 demands that after 12 weeks in a controlled composting test, no more than 10% of the material remains on a 2mm sieve. ASTM D6400 requires that after 12 weeks, the material must fragment to less than 10% of its original weight, with no visible distinction from the compost matrix. In practice, this means a PLA spoon that passes ASTM D6400 might fail EN 13432 if it leaves slightly larger fragments. Our lab tests show that a 500ml PLA cup from our line passes both, but a 1mm thicker wall could tip the balance.

One common misconception: 'biodegradable' is not the same as 'compostable.' Biodegradable only means it breaks down—no time limit, no toxicity check. Compostable means it breaks down fast enough (180 days) and leaves no toxic residue. Always look for the certification logo, not just the word.

What Are the Ecotoxicity Requirements in Each Standard?

Both standards include a plant growth test to ensure the compost is not phytotoxic. ASTM D6400 follows OECD 208 or ASTM E1963, requiring that the compost support at least 90% of the germination and biomass growth of a control. EN 13432 uses a similar approach but with specific test species (e.g., barley, cress) and a higher threshold: the compost must not inhibit growth by more than 10% compared to a blank. Our bagasse plates passed both, but we noticed that some PLA blends with additives can fail the EN 13432 ecotoxicity test due to heavy metal leaching from colorants.

Heavy metal limits are also stricter in EN 13432. For example, EN 13432 caps zinc at 150 ppm, while ASTM D6400 allows 300 ppm. If you’re sourcing compostable cutlery from Asia, check the pigment—some reds and yellows contain cadmium or lead that exceed EU limits. Our factory switched to organic pigments years ago to avoid this issue.

Another difference: EN 13432 requires that the compost be tested for ecotoxicity within 90 days of the test start, while ASTM D6400 does not specify a strict timeline. This can affect certification timelines—expect 6-9 months for EN 13432 from sample submission to certificate, versus 4-6 months for ASTM D6400.

Table: Key Differences Between ASTM D6400 and EN 13432

Which Certification Is More Widely Accepted Globally?

EN 13432 has broader international acceptance because many countries outside the EU have adopted it as a reference—like Japan, Australia, and parts of South America. ASTM D6400 is dominant in North America and some Asian markets like Korea. If you’re exporting to both regions, you’ll likely need both certifications. However, some retailers (e.g., Walmart, Carrefour) accept either if the product is clearly labeled.

A practical tip: check with your buyer. A European importer of compostable straws told us they only accept EN 13432 with the Seedling logo. A US fast-food chain required BPI certification for their PLA-lined paper bowls. We’ve also seen a trend: some global brands now demand both to simplify their supply chain. Our factory maintains dual certification for our best-selling bagasse plates—it adds about $3,000/year in recertification costs but opens 30% more markets.

One nuance: China’s GB/T 28206-2011 is largely based on EN 13432, so if you sell to China, EN 13432 is the safer bet. For India, IS/ISO 17088 is similar to ASTM D6400. Always verify with a local agent.

How Do the Test Methods for Disintegration Compare?

Disintegration testing simulates industrial composting conditions. For ASTM D6400, the test uses a pilot-scale composter (ASTM D5929) where the material is mixed with compost and kept at 58°C for 12 weeks. The material must break down so that no more than 10% remains on a 2mm sieve. EN 13432 uses a similar method (ISO 16929) but with a different reference compost and a stricter requirement: the compost must be mature and stable before the test, which can affect results.

We once tested a kraft paper bowl coated with a thin PLA film. It passed ASTM D6400 disintegration but failed EN 13432 because the film did not disintegrate enough in the first 4 weeks—the test lab said the compost was too active and caused the film to ball up. We reformulated the coating thickness from 25 microns to 20 microns, and it passed both. Lesson: test early with both standards if you target multiple markets.

Another difference: EN 13432 requires a second disintegration test if the material is thicker than 2mm. ASTM D6400 does not have this thickness clause. So a thick bagasse plate (3mm) may only need one test for ASTM but two for EN 13432, doubling the cost.

What Are the Common Misconceptions About These Standards?

Biggest myth: 'If it’s ASTM D6400 certified, it’s automatically EN 13432 certified.' False. While both standards are harmonized in principle, the specific test methods and thresholds differ enough that a product can pass one and fail the other. We’ve seen PLA resin that passed ASTM but failed EN due to higher heavy metal content. Always test to the specific standard you need.

Second myth: 'Home compostable is the same as industrial compostable.' Neither ASTM D6400 nor EN 13432 covers home composting. They require industrial conditions (58°C). Home composting is a different standard (e.g., AS 5810, NF T 51-800) with lower temperatures and longer timeframes. Don’t label a product 'home compostable' unless it’s certified for that.

Third myth: 'Biodegradable plastics are always compostable.' Not true. Some oxo-degradable plastics fragment into microplastics but don’t biodegrade fully—they are not compostable under either standard. In fact, the EU has banned oxo-degradable plastics. Stick to certified compostable materials like PLA, bagasse, or kraft paper with a bio-based coating.

How Should B2B Buyers Choose Between ASTM D6400 and EN 13432?

Start with your target market. If you supply to US restaurants or retailers, prioritize ASTM D6400 with BPI certification. If you export to Europe, EN 13432 with the Seedling logo is non-negotiable. For global brands, get both—it’s an investment that pays off through wider market access. Our data shows that dual-certified products command a 10-15% price premium over single-certified ones because buyers value the flexibility.

Also consider your supply chain. If your compostable cutlery is made in China, many factories already have EN 13432 certification because it’s more common there. But if you source from the US, ASTM D6400 is the default. We recommend asking for test reports from an accredited lab (e.g., BPI, DIN CERTCO) before placing a large order. A 50,000-unit order of PLA cups costs around $0.08-0.12 per piece; re-testing after production can add $2,000-5,000 in delays.

Finally, don’t ignore the labeling requirements. ASTM D6400 allows the term 'compostable' without a logo, but many retailers require the BPI logo. EN 13432 requires the Seedling logo on the packaging. Without it, your product may be rejected at customs. We’ve seen a shipment of bagasse clamshells held at Rotterdam because the Seedling logo was printed in black instead of green—a minor detail with major consequences.

What is the difference between ASTM D6400 and EN 13432 certification costs?

ASTM D6400 certification typically costs $5,000-$10,000 for initial testing and around $2,000/year for renewal. EN 13432 is more expensive: $8,000-$15,000 initial and $3,000-$5,000 annually. The higher cost reflects stricter testing and the need for a European-based certifying body. For a small business, this can be a barrier, but volume discounts are available if you certify multiple products at once.

Can a product be certified under both ASTM D6400 and EN 13432 simultaneously?

Yes, many products are dual-certified. You submit samples to both BPI (or CMA) and DIN CERTCO (or TÜV Austria). The tests are run separately, but if your material is robust, it will pass both. Some labs offer a combined test package that reduces duplication—for example, using the same compost for both disintegration tests. Expect to pay around $12,000-$18,000 for dual certification, but it’s worth it for global reach.

How often do these standards get updated?

ASTM D6400 was last revised in 2021 (D6400-21), and EN 13432 was updated in 2022 (EN 13432:2022). Changes are usually minor—e.g., clarifying test conditions or updating reference standards. Keep an eye on your certification renewal dates; you may need to retest if the standard changes significantly. Our factory recertifies every 2 years to stay current.