What’s EN 13432 and How Does It Differ From ASTM?

If you’ve spent any time in compostable packaging procurement, you’ve seen two acronyms repeated on every spec sheet, marketing one-pager, and supplier capability deck: EN 13432 and ASTM D6400. They get mentioned together so often that most buyers come away thinking they’re the same standard with two regional names.

They aren’t. They overlap heavily, but they were written by different bodies for different markets, sit underneath different regulations, and use different reference frameworks for the parts that matter — especially heavy metals and end-of-life infrastructure assumptions. Knowing where they diverge is the difference between specifying packaging that passes a real customs inspection or a real procurement audit, and specifying packaging that has to be reformulated, relabeled, or pulled.

This piece walks through what each standard actually tests, where the numbers diverge, which certifying marks back each one, and how to think about the choice when you’re sourcing compostable packaging for cross-border supply chains.

What EN 13432 Is, in Plain Terms

EN 13432 is the European standard titled “Requirements for packaging recoverable through composting and biodegradation.” It was published by the European Committee for Standardization (CEN) in 2000 and has been revised periodically since.

The reason it carries weight beyond “another standard” is that it’s referenced inside EU Directive 94/62/EC on packaging and packaging waste. That regulatory linkage is what gives EN 13432 teeth. A packaging product that meets EN 13432 has a recognized regulatory pathway to claim “compostable” in EU member states. A product that doesn’t meet it, regardless of how good it looks in tests, doesn’t have that pathway.

The standard sets four classes of requirement:

1. Chemical composition. Volatile solids must be at least 50%. Heavy metal concentrations (zinc, copper, nickel, cadmium, lead, mercury, chromium, molybdenum, selenium, arsenic, fluorine) are capped at specific levels. Hazardous substances must be absent.
2. Biodegradability. At least 90% of the organic carbon in the test material must be converted to CO2 within six months under controlled industrial conditions (58°C ±2°C).
3. Disintegration. At least 90% of the test material must pass through a 2mm sieve after 12 weeks of composting in a pilot-scale facility.
4. Ecotoxicity. The finished compost must not negatively affect plant growth, tested per OECD 208 with two plant species.

The four pillars get tested independently. A product that passes biodegradation but fails ecotoxicity is not EN 13432 compliant. A product that passes everything except heavy metals is not compliant either. There are no partial credits.

What ASTM D6400 Is, in Plain Terms

ASTM D6400 is the US standard titled “Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities.” It was first published by ASTM International in 1999 and has been revised several times since.

ASTM D6400 is not directly tied to a federal regulation in the same way EN 13432 is tied to the EU Packaging Directive. The US federal compostability framework is looser. What gives ASTM D6400 practical authority is the Biodegradable Products Institute (BPI) certification program, which uses ASTM D6400 (and the related ASTM D6868 for paper-coated products) as the basis for its widely-recognized certification mark, plus the Federal Trade Commission Green Guides, which point to ASTM D6400 compliance as a defensible basis for compostability claims.

The substantive requirements are similar to EN 13432:

1. Chemical composition. Heavy metal limits, set at 50% of EPA Class A biosolid concentrations (a different reference framework from EN 13432’s CEN values). No fluorine cap. Volatile solids requirement is the same 50%.
2. Biodegradation. At least 90% conversion of organic carbon to CO2 within 180 days for blends; 60% for homopolymers and copolymers, with the rest of the carbon required to be in the form of biomass that itself is non-toxic.
3. Disintegration. At least 90% pass-through on 2mm sieve at 84 days (12 weeks).
4. Ecotoxicity. Per OECD 208, tested on two plant species.

The shape is the same as EN 13432. The numbers and reference frameworks behind those numbers are not always the same.

Where the Two Standards Actually Diverge

Side by side, these are the differences that matter in practice.

Heavy metal references. EN 13432 uses CEN-defined limits. ASTM D6400 uses 50% of EPA Class A biosolid limits. For most metals the values land within a similar range, but a product can pass one and marginally fail the other depending on the input. Cadmium, mercury, and lead are the metals where this comes up most often — typically as contaminants in pigments, inks, or recycled content, not in the base resin.

Fluorine. EN 13432 caps fluorine. ASTM D6400 doesn’t have an explicit fluorine limit. That sounds minor until you consider per- and polyfluorinated alkyl substances (PFAS). Bagasse and paper food packaging have historically used PFAS for grease resistance. EN 13432 effectively rules them out; ASTM D6400 doesn’t, which is why several US states have had to legislate PFAS bans separately from any compostability standard.

Biodegradation thresholds for blends. EN 13432 sets a flat 90% threshold for the whole material. ASTM D6400 differentiates between homopolymers/copolymers (60% threshold) and blends (90% threshold). For multi-material laminates and coated papers, this distinction can change which standard a given product passes.

Test duration framing. EN 13432 talks in months (six). ASTM D6400 talks in days (180). Same window, different framing in product literature, sometimes confusing for procurement teams comparing data sheets.

Heavy metal list. EN 13432 lists eleven elements. ASTM D6400 lists fewer (typically nine). The extra elements in EN 13432 — particularly molybdenum and selenium — are unlikely to be a problem for most plant-derived feedstocks but matter for specialty products with mineral additives.

Pilot-scale vs full-scale. Both standards rely on pilot-scale composting tests rather than full industrial trials. The pilot conditions are similar but not identical, which is why some products test slightly differently between European and American labs even at notionally equal protocols.

Regulatory anchoring. This is the biggest practical difference. EN 13432 sits inside the EU’s packaging regulation. ASTM D6400 sits as a voluntary specification that gets pulled into BPI certification, FTC guidance, several US state laws, and California’s SB 1335. Both have weight. They have different kinds of weight.

The Certifying Bodies and Their Marks

Standards on a page don’t certify anything. Test labs and certification programs do. Here’s the practical map:

EN 13432–based marks (Europe):

• OK Compost (TÜV Austria, formerly Vinçotte) — the most widely recognized industrial-compost mark in Europe. Indicates compliance with EN 13432.
• DIN-Geprüft Industrial Compostable (DIN CERTCO) — German equivalent, also EN 13432–based.
• Compostable Logo (European Bioplastics) — EN 13432 compliance via accredited testing.
• Seedling Logo — original mark from European Bioplastics, also tied to EN 13432.

ASTM D6400–based marks (US):

• BPI Compostable Logo — the dominant US industrial-compost mark. Tests against ASTM D6400 and ASTM D6868 (for fiber-based products with bioplastic coatings).
• CMA Approved (Compost Manufacturing Alliance) — tests under field conditions at actual composting facilities. More demanding than lab certification because it accounts for real-world disintegration variability.

Other regional and home-compost marks worth knowing:

• AS 4736 (Australia) — Australian industrial-compostable standard, similar in shape to EN 13432.
• OK Compost HOME (TÜV Austria) — home-composting certification at lower temperatures (around 20-30°C). Different test conditions, much more demanding for the product.
• TÜV Home Compost / DIN-Geprüft Home Compostable — additional home-compost marks.
• ISO 17088 — international standard that pulls in EN 13432–style requirements; rarely cited on its own but appears in multinational tenders.

A product can hold multiple marks at once. Most premium suppliers test once and then apply across regions. The certifications cost money and time to maintain, so smaller suppliers may hold one mark and not the others.

Which One Do You Actually Need?

The honest answer depends on three things: where the product is sold, who is buying it, and what compost system processes it at end of life.

Selling into the EU? EN 13432 (or its OK Compost / Seedling equivalent) is the default. Buyers, retailers, and regulators all anchor to it. Asking for it is a baseline conversation, not a stretch ask.

Selling in the US? BPI certification (ASTM D6400) is the default. Several states — Washington, California, Maryland, New York — have specific labeling laws referencing it. Selling products labeled “compostable” without BPI or equivalent ASTM compliance has gotten brands into FTC trouble.

Selling into both markets? Test once to whichever is more demanding for your specific material (often EN 13432 because of the fluorine cap and broader metal list), then apply the appropriate regional certification on top.

Selling for home-compost end of life? Neither EN 13432 nor ASTM D6400 alone is sufficient. The product needs an OK Compost HOME or DIN Home Compostable mark on top.

Selling for industrial-compost end of life only? Either standard works on its own. The choice is regional convenience plus customer expectation.

If you’re sourcing across categories — whether that’s compostable food containers, compostable bowls, or compostable utensils — the practical advice is to ask suppliers for both marks where they have them, document which mark each SKU carries, and align that to the region and customer mix you actually serve. Mixed catalogues with inconsistent certification create the procurement headache that often kills a compostable program before it gets going.

The Common Procurement Mistakes

A few patterns repeat in B2B buying conversations.

Treating “biodegradable” and “compostable” as synonyms. Biodegradable means it will break down eventually under some conditions. Compostable means it meets a specific standard with defined thresholds and a defined facility type. EN 13432 and ASTM D6400 both certify the second; neither certifies the first. Suppliers who lead with “biodegradable” without naming a standard are usually not certified.

Accepting a test report instead of a certification. A lab test against EN 13432 protocols is not the same as ongoing certification with a recognized mark. Certifications come with audit cycles and renewal obligations. A six-year-old test report is not certification.

Assuming bagasse and PLA are automatically compliant. Bagasse may have PFAS coatings that fail EN 13432’s fluorine cap. PLA is usually compliant for industrial composting but rarely for home composting. The material isn’t the certification; the specific tested product is.

Asking only for the BPI mark in EU markets, or only for OK Compost in US markets. Customs officers and procurement officers want to see the mark recognized in their region. Even if a product technically passes the other standard, the wrong mark on the box can stall a shipment.

Confusing TÜV Austria’s OK Compost with their OK Compost HOME mark. They are different programs at different temperatures with different pass thresholds. A product certified for industrial composting will not necessarily pass home-compost testing.

What to Pull From a Supplier Spec Sheet

When you’re evaluating compostable packaging, the certification line on the spec sheet should answer five questions:

1. Which standard? (EN 13432, ASTM D6400, or both)
2. Which certifying body? (TÜV Austria, BPI, DIN CERTCO, etc.)
3. What’s the certificate number?
4. When was it last renewed?
5. Is it for industrial or home composting?

If any of those five are missing or vague, the supplier doesn’t actually have the certification they’re implying. A real certification is auditable. A marketing claim isn’t.

The Standards Are Converging, Slowly

ISO 17088 has been quietly aligning the international landscape for years. Its current revision pulls heavily from EN 13432 and brings ASTM D6400 closer to the European framework. Several Asian markets — Japan (GreenPla), Korea, parts of Southeast Asia — are using ISO 17088 as the basis for their own labeling rules. The long arc of compostability standards is convergence, not divergence.

Until that convergence finishes, the practical reality for B2B buyers is to know both standards, ask for the right marks for the right markets, and verify the certification is current. The two acronyms aren’t interchangeable today. They tell you slightly different things, point at slightly different test labs, and carry slightly different regulatory weight. Get them right at the spec stage and the rest of the compliance work — labeling, customs, procurement — gets easier.

Get them wrong, and you find out at the worst time: when a customer asks for documentation, an inspector pulls a sample, or a state law tightens around an unspecified margin. The standards are imperfect. They are still the most reliable shorthand the industry has for “this packaging will actually compost.” Learn what each one really says, and the rest of the compostable packaging conversation gets a lot more grounded.