EN 13432 and ASTM D6400 are the two certifications that separate genuinely compostable packaging from marketing claims. If a supplier can't point to one of these, "compostable" is just a word on a bag.
What these standards actually test
Both standards require a packaging material to pass a battery of lab and field tests before it can be legally called compostable. Broadly, these cover four things:
- Biodegradation: At least 90% of the material must convert to CO2 within 180 days under controlled composting conditions.
- Disintegration: After 12 weeks of composting, no more than 10% of the material should remain as fragments larger than 2mm.
- Ecotoxicity: The resulting compost must not harm plant growth, and heavy metal content must stay below strict limits.
- Composition: Volatile solids and heavy metal concentrations must fall within defined thresholds.
EN 13432 vs. ASTM D6400 — what's the difference?
EN 13432 is the European standard (administered by bodies like TÜV Austria and DIN CERTCO), while ASTM D6400 is the American equivalent. The testing criteria are very similar in substance — both require industrial composting conditions rather than home composting — but they're recognised by different regulatory and retail markets. A packaging manufacturer serving international buyers often certifies against both.
Industrial composting vs. home composting
This is one of the most misunderstood points: EN 13432 and ASTM D6400 certify performance in industrial composting facilities, which run at consistently higher temperatures (around 58°C) than a typical home compost bin. A certified compostable bag may take considerably longer to break down in a backyard compost heap. Some manufacturers additionally test for home compostability under separate standards (like AS 5810 in Australia) — worth asking about if that's how your customers will dispose of the bags.
How to verify a supplier's claim
- Ask for the certificate number, not just the logo — logos can be copied, certificate numbers can be checked with the issuing body.
- Confirm which standard was tested (EN 13432, ASTM D6400, or both) and the certifying lab.
- Check that the certificate covers the specific product (thickness, resin blend) you're buying — certification is product-specific, not company-wide.
- Ask whether the certification is current; these certifications are typically renewed periodically.
A genuine certificate is product-specific and traceable. If a supplier only offers a generic "eco-friendly" claim with no certificate number, that's a signal to ask more questions.
Why Greensack certifies to these standards
Greensack bags are manufactured to meet EN 13432 and ASTM D6400 compostability benchmarks, alongside ISO quality certification. For institutional buyers, retailers, and municipal contracts where compliance documentation is required, we can share certification details on request — get in touch for the latest documentation for your order.