The Basics of EN Compostability Standards: EN 13432 and What It Means

“Compostable” is a useful marketing word but a slippery technical claim. A product can biodegrade in 6 months on a backyard pile and still fail at a commercial composting facility. A product can disintegrate visually but leave behind plastic microfragments. A product can break down beautifully in a lab and fail in the field.

Standards organizations have spent decades trying to nail down what “compostable” actually means as an engineering claim. In Europe, the dominant standard is EN 13432 — the European Norm for packaging recoverable through composting and biodegradation. If you’ve ever seen a “seedling logo” or “OK Compost” mark on European compostable packaging, you’ve seen EN 13432 in action.

This article walks through what EN 13432 actually requires, how the certification process works, how it compares to the US ASTM standards, and why it matters even if you’re not selling in Europe.

The four required criteria

EN 13432 specifies four criteria that a packaging product must meet to claim compostability:

1. Disintegration

The product must visually disintegrate after 12 weeks in a composting environment. Specifically:

• After 12 weeks of composting under controlled conditions, no more than 10% of the original mass of test material may remain on a 2mm sieve.
• The composting environment for testing is industrial-scale composting (51-60°C operating temperature, controlled moisture, aerobic conditions).
• The 2mm sieve threshold ensures that the product has physically broken down into small enough pieces to integrate with the surrounding compost rather than persisting as visible debris.

This criterion alone disqualifies many products that biodegrade slowly. A piece of conventional paper may pass; a chunk of thick plastic film won’t pass even if its underlying chemistry is biodegradable.

2. Biological degradation

The product must achieve at least 90% biodegradation within 6 months under controlled aerobic composting conditions.

• Biodegradation is measured as CO2 evolution — the CO2 released by the product’s decomposition compared to a control reference.
• The test is conducted at 58°C (136°F) under controlled moisture and oxygen conditions.
• 90% conversion to CO2 means at least 90% of the carbon in the original product has been mineralized to CO2 by microbes.

This criterion separates true biodegradation from physical fragmentation. A product that breaks into invisibly-small plastic fragments would pass disintegration but fail biodegradation.

The 90% threshold matters. A 60-70% biodegradation rate, which some older “biodegradable” plastics achieved, isn’t sufficient for EN 13432. True compostability under this standard requires nearly complete mineralization.

3. Heavy metals and toxicity

The product must not contain heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, zinc) above specified concentration limits.

• The limits are based on EU regulatory thresholds for finished compost being used as a soil amendment.
• The thresholds protect both compost quality and downstream soil/food chain safety.

This criterion ensures that decomposing the product doesn’t release toxic substances into the resulting compost. It’s not just about whether the product breaks down; it’s about what’s left behind.

Most plant-based and certified-organic-feedstock materials pass easily. Products with metal-bearing inks, certain pigments, or contamination from manufacturing may fail.

4. Ecotoxicity

The finished compost (after the product has decomposed) must not show ecotoxic effects on plant growth.

• The test method is a plant-growth bioassay: seeds are germinated in compost containing the decomposed test material and compared to compost from a control.
• If plant growth is significantly impaired, the product fails this criterion.

This is the most “end of life and what happens next” criterion. A product can biodegrade fully, pass heavy metal tests, and still leave behind compounds that suppress plant growth. EN 13432 requires that the resulting compost is fit for its intended use.

The “seedling logo” certification

EN 13432 itself is the technical standard. Compliance with the standard is certified by accredited third-party organizations, of which the most prominent are:

TÜV Austria (formerly Vincotte): issues the OK Compost certification. Two variants:
– OK Compost Industrial — equivalent to EN 13432 (industrial composting at 58°C).
– OK Compost Home — stricter (composts at lower 20-30°C ambient temperatures, suitable for backyard composting).

DIN-CERTCO (Germany): issues the DIN-CERTCO certification, also based on EN 13432.

When a European compostable product carries the “seedling logo” (a small green seedling icon), it’s typically referring to OK Compost or DIN-CERTCO certification under EN 13432.

The certification process for a new product takes 6-12 months and costs €5,000-€20,000 in testing fees, depending on product complexity. For a manufacturer launching a new compostable foodware line, certification is a meaningful project — not a marketing checkbox.

How EN 13432 compares to ASTM D6400

The US equivalent is ASTM D6400 (Standard Specification for Compostable Plastics), with related standards for paper-based products (ASTM D6868) and PHA-specific applications (ASTM D5511, D5526).

Similarities:

• Both require >90% biodegradation under controlled conditions.
• Both require visual disintegration.
• Both test for heavy metals and ecotoxicity.
• Both use 58°C as the standard composting temperature.

Differences:

• Time scale for disintegration: EN 13432 specifies 12 weeks; ASTM D6400 specifies 12 weeks for standard products but allows up to 26 weeks for higher-mass products.
• Certification labeling: EN 13432 leads to “seedling logo” or “OK Compost”; ASTM D6400 leads to BPI (Biodegradable Products Institute) certification.
• Heavy metal thresholds: EN 13432 uses EU regulatory thresholds (generally stricter); ASTM D6400 uses EPA thresholds.
• Validation by composting facilities: ASTM D6400 doesn’t require field validation; EN 13432 doesn’t explicitly require it either, but most CMA (Compost Manufacturing Alliance) US programs add a field-test layer.

For practical purposes, a product certified to one standard is typically very close to compliant with the other. A BPI-certified product can usually pass EN 13432 testing with limited modification. The standards converge more than they diverge.

What EN 13432 doesn’t cover

It’s worth noting the limits:

Backyard composting performance: EN 13432 only covers industrial composting. Many products certified under EN 13432 do not break down in backyard piles. For products intended for home composting, the OK Compost Home certification (stricter) is the relevant mark.

Marine biodegradation: EN 13432 doesn’t address whether a product breaks down in marine environments. For products like compostable beach products or fishing accessories, separate marine biodegradation standards apply (ASTM D7081, OK Marine).

Soil biodegradation: EN 13432 doesn’t cover whether a product breaks down in soil at ambient temperatures. Products buried in agricultural soil may not decompose in the same time frame as in industrial composting.

Marketing claims: EN 13432 covers the product’s technical performance, not the marketing claims around it. A product can be EN 13432 certified and still be marketed in ways that mislead consumers (e.g., implying backyard compostability when only industrial works).

How facilities use EN 13432

Industrial composting facilities use EN 13432 certification to decide what to accept into their operations.

In Europe (and increasingly in North America), commercial composters operate under strict feedstock policies. Only certified products enter the compost stream; non-certified packaging (even if labeled “biodegradable”) gets rejected.

This creates a clean operational distinction:

• Certified compostable products (EN 13432 / BPI): accepted into commercial compost streams, integrate with food waste, finish as soil amendment.
• Marketed as “biodegradable” but uncertified: rejected at the facility, contaminate the load (if mis-sorted by consumers), and end up in landfill.
• Conventional plastics: rejected, contaminate the load (if mis-sorted), result in significant facility cleanup costs.

The certification protects the facility’s operation. Without standards, commercial composters would be unable to maintain product quality of finished compost — too many wildcard inputs.

What this means for procurement

For B2B buyers of compostable packaging, EN 13432 (or its US equivalent BPI) is the minimum bar. Without certification, “compostable” claims are unenforceable and likely won’t be accepted by commercial composting facilities.

When sourcing compostable foodware — bagasse compostable food containers, PLA compostable cups, CPLA compostable utensils — verify the certification status of every SKU. A supplier portfolio where some products are certified and others aren’t is a red flag; ask why.

Some specific questions to ask suppliers:

1. For each in-scope SKU, what’s the certification status (EN 13432, BPI, both)?
2. When was the certification last renewed? (Certifications need periodic renewal.)
3. Is the certification for the finished product, or just for the underlying material? (A bowl made from a BPI-certified resin isn’t necessarily a BPI-certified bowl.)
4. Are certificates available as PDFs? (You should be able to download or request them.)
5. Are there any products marketed as compostable without certification? (If yes, ask why.)

For multinational operators with both US and EU operations, dual certification (BPI + EN 13432) is common. The cost is higher per SKU but the supply chain simplification is worth it.

The role of EN 13432 in EU regulation

Beyond product-level certification, EN 13432 plays a role in EU regulatory frameworks:

Packaging and Packaging Waste Regulation (PPWR): the 2024-2026 EU regulation tightens recyclability and compostability standards. Products labeled as compostable must meet EN 13432 (or stricter) to be sold in EU markets after 2026.

Single-Use Plastics Directive (SUPD): the 2019 directive bans certain single-use plastic items unless they meet specific biodegradability/compostability criteria. EN 13432 is the operational standard.

National implementations: EU member states often add their own requirements on top of EN 13432. France, Italy, and Germany have particularly active national-level rules.

For US companies exporting to EU markets, EN 13432 isn’t optional. Products without certification can’t legally claim compostability in EU markets.

A historical note

EN 13432 was published in 2000 and has been revised several times. The current operational version reflects two decades of refinement from real-world commercial composting facility experience.

Earlier “biodegradable” standards (BS 7755, German DIN V 54900, others) lacked the rigor of EN 13432. Many older products were marketed as biodegradable but in practice fragmented into microplastics or simply didn’t break down in commercial conditions.

EN 13432 closed those loopholes. The dual requirement of disintegration AND biodegradation AND no heavy metals AND no ecotoxicity covers most of the ways a “biodegradable” product can fail in real operations.

Common misconceptions about EN 13432

A few common errors:

“EN 13432 certified = backyard compostable.” No. EN 13432 covers industrial composting at 58°C. Backyard piles rarely sustain those temperatures. For backyard claims, OK Compost Home is the standard.

“EN 13432 certified = ocean degradable.” No. Marine biodegradation has separate standards. EN 13432 says nothing about ocean fate.

“EN 13432 certified = compostable everywhere.” No. The product is compostable in any facility operating under EN 13432-compatible conditions. Facilities outside the EU may have different operating protocols; verify each market.

“EN 13432 certification means the product is 100% bio-based.” No. EN 13432 is about end-of-life behavior, not raw material sourcing. Some EN 13432-certified products are made from fossil-derived materials that happen to biodegrade (rare but possible).

“EN 13432 is the same as ASTM D6400.” Close but not identical. They converge on most criteria but differ in details and accepted regional usage. Dual-certified products are common for products sold in both markets.

A look forward

EN 13432 is a mature, working standard. Its near-term evolution focuses on:

Tighter heavy metal thresholds: EU regulatory pressure is reducing acceptable heavy metal levels in compost, which may push EN 13432 criteria tighter over time.

Microplastic concerns: while EN 13432 implicitly addresses microplastic generation through the biodegradation criterion, newer standards may require explicit microplastic-formation testing.

Marine and ambient-soil biodegradation: these are likely to be addressed via separate standards rather than incorporating into EN 13432 itself.

Carbon accounting: future revisions may require LCA-style carbon disclosure as part of certification, beyond the current biodegradation criterion.

The standard isn’t going anywhere; it’s evolving in the direction of tighter requirements and broader applicability.

A worked-through example: a PLA cup applying for certification

To make the certification process concrete: consider a 12-oz PLA cold cup that a US manufacturer wants to certify under EN 13432 to enable EU market sales.

Step 1: Application and product spec. The manufacturer submits the product specification, material composition (NatureWorks PLA 4032D resin with mineral colorant), and intended use (cold beverage service) to TÜV Austria. Initial application fee: €1,500-€3,000.

Step 2: Laboratory testing — disintegration. Test samples of the cup are placed in a controlled composting environment at 58°C. After 12 weeks, residual material is sieved at 2mm. Result: 4.2% residual mass on the sieve (well below the 10% threshold). Cost of disintegration testing: €4,000-€6,000.

Step 3: Laboratory testing — biodegradation. Parallel test: CO2 evolution measurement under controlled aerobic conditions. After 90 days at 58°C, the cup achieves 94% biodegradation relative to a cellulose control. Above the 90% threshold; passes. Cost: €5,000-€8,000.

Step 4: Heavy metals analysis. Chemical analysis confirms no heavy metals above EU thresholds. Cost: €2,000-€3,500.

Step 5: Ecotoxicity bioassay. Finished compost from the test composted with the cup is tested via plant-growth assay. Cress and barley seeds germinate at >90% the control rate; passes. Cost: €3,000-€5,000.

Step 6: Certification issuance. TÜV Austria issues OK Compost Industrial certification for the specific SKU. The cup can now carry the seedling logo and be sold into EU markets with compostable claims. Total time: ~9 months from initial application. Total cost: €15,000-€26,000.

Step 7: Maintenance. The certification requires renewal every 3-5 years, with continued surveillance audits and any compositional changes triggering re-testing.

For a manufacturer with a product line of 30-50 SKUs, full EN 13432 certification across the portfolio represents an investment of €450,000-€1.3 million. This is why smaller suppliers often have only a subset of their products certified — the cost of certification is meaningful.

For larger manufacturers (World Centric, Vegware, Eco-Products), certification across the full portfolio is treated as a routine cost of doing business in the compostable packaging market.

Bottom line

EN 13432 is the European standard that defines what “compostable” means as an engineering claim. The four criteria — disintegration, biodegradation, no heavy metals, no ecotoxicity — together describe what a product must do to be safely composted in industrial facilities.

For B2B procurement of compostable packaging, EN 13432 (or its US equivalent BPI) is the minimum credible certification. Without it, “compostable” claims are unenforceable. Commercial composting facilities use these certifications to decide what to accept; consumers (especially in Europe) use them to decide what to put in compost bins.

The standard doesn’t cover everything — it doesn’t address backyard composting, marine biodegradation, or carbon footprint. But for the specific question “will this product break down properly in a commercial compost facility?” EN 13432 is the answer that holds up to engineering scrutiny.

For US companies sourcing compostable packaging, treat BPI certification as your default. For EU operations, EN 13432 (with OK Compost or DIN-CERTCO certification) is required. For global operations, dual certification is worth the cost.

The standard exists because real composting operations need it. Use it.

For B2B sourcing, see our compostable supplies catalog or compostable bags catalog.

Background on the underlying standards: ASTM D6400 defines the U.S. industrial-compost performance bar, EN 13432 harmonises the EU equivalent, and the FTC Green Guides govern how “compostable” can be marketed on packaging in the United States.