Two standards, one idea
EN 13432 is the European standard for packaging recoverable through composting. ASTM D6400 is the US specification for plastics designed to be aerobically composted in municipal or industrial facilities. Both set out what a material or item has to show in laboratory and pilot testing before it can be called compostable in an industrial composting setting: that it breaks down biologically, that it disintegrates into fragments that do not remain visible in the finished compost, and that the resulting compost is not harmed. The detailed criteria, test methods and durations are set in each standard and are read with the test lab and the certification body.
Neither standard is a home composting standard. A container certified to EN 13432 or ASTM D6400 is expected to compost in a managed industrial facility with controlled temperature and moisture, not in a garden heap. That distinction drives how the claim must be worded.
Certification, not self-declaration
A test report shows that a sample passed. A certificate, issued by a certification body after reviewing the test evidence, shows that a named product, made of a named material at a stated maximum thickness or weight, conforms to the standard, usually with a certificate number and a validity period. For packaging claims the certificate is what retailers, marketplaces and enforcement bodies ask for, and it is what the desk requires before any compostable wording appears on a lid, sleeve, carton or listing.
| Field | What to look for | Common gap |
|---|---|---|
| Standard | EN 13432 or ASTM D6400, named exactly | A home composting or soil scheme quoted as if it were industrial |
| Certificate holder | The partner plant, the material producer or your brand | A material supplier's certificate used for a finished item without a link |
| Product scope | Item name, model, material, maximum thickness or weight | A thinner item certified, a heavier item sold |
| Certificate number | Present and checkable with the issuing body | Number missing or belonging to another product |
| Validity | Current dates | Expired certificate in a sales deck |
| Additives and coatings | Inks, coatings and barrier layers covered | Printed or coated version not in scope |
Why thickness and gram weight matter
Compostability depends on how much material has to break down. Certificates therefore usually cap the thickness or weight of the certified item. A spoon at 1.6 g and a spoon at 1.1 g, or a 500 ml bowl and a 1,000 ml bowl from the same material, are not interchangeable on a certificate unless the scope covers both. When the desk compares quotes, gram weight is on every line for this reason as well as for cost; see gram weight and wall thickness.
Starch and PP blends do not qualify
The starch-based containers in this range are described in partner plant literature as corn starch and are filed under PP thermoforming, so the desk treats them as a starch and PP blend, ratio to be confirmed per spec. A blend that contains conventional PP is not a compostable material and holds no EN 13432 or ASTM D6400 certificate, so these containers are described as starch and PP blend with lower plastic content, never as compostable or biodegradable. Buyers who need a certified compostable item should specify that at the start, so the desk can shortlist partner plants that hold certificates for the exact model rather than retrofit a claim onto an existing range. See starch-based containers.
Certification and market rules are separate
A compostable certificate answers an end of life question. It does not answer whether an item may be sold. In the EU, the Single-Use Plastics Directive 2019/904 treats PLA and other chemically modified bioplastics as plastic, so a certified compostable PLA fork is still single-use plastic cutlery and has been banned from the EU market since 3 July 2021. In the US, a certified molded fibre bowl still has to meet state PFAS rules, such as California AB 1200 for plant fibre food packaging since 1 January 2023. The certificate, the market rules and the food contact file are three different checks.
Wording a certified claim in the US
Under the FTC Green Guides at 16 CFR 260.7, a compostable claim should be qualified where municipal or institutional composting facilities are not available to a substantial majority of consumers or communities where the item is sold. In practice certified items are often described as commercially compostable, certified to ASTM D6400 or EN 13432, with the certificate number, and with wording that does not imply home composting. Confirm the wording for each market with your counsel. The Green Guides note covers degradable claims in more detail.
Questions to put to a partner plant
When a plant offers compostable items, a short set of questions sorts real certification from sales language. Who holds the certificate, and does it name this model or only the base material? Which standard, and which certification body issued it? What is the maximum thickness or weight in scope, and how does that compare with the item quoted? Are the print, inks and any coating or barrier layer covered? Is the certificate current, and can its number be checked with the issuing body? Does the plant also hold food contact documents for the same item, and a PFAS statement where the item is plant fibre for the US? A plant that answers all of these in writing is a plant the desk can put on the shortlist.
How the desk handles compostable programs
- Confirm that the buyer needs a compostable claim and in which markets.
- Shortlist partner plants that hold certificates for the exact item type.
- Check each certificate against the table above and with the issuing body.
- Match the order spec to the certified scope: material, weight, print and coating.
- Run the normal food contact and market checks alongside, including PFAS for fibre.
- Approve claim wording with the brand and its counsel before artwork.
Certificates are issued to partner plants, material producers or your brand per project and verified by the desk; Lidwell does not hold them. Certified items often have their own minimums and lead times, confirmed in writing per program; typical ranges are on MOQ and lead time, and the material routes are compared in the sustainable packaging guide. Send the item list and target markets through the quote form.