Compostable Packaging Certification: What Is Tested and What You May Claim

A hang tag printer switched its garment bags to a compostable film and printed the OK compost logo on them. The shipment was rejected in Europe: the film really was compostable, but the certificate was held by someone else and the logo was never licensed. This happens every year, and the failure is almost never the material — it is the chain between certificate and claim.

This guide covers five things: the three words everybody confuses, what certification actually tests, industrial versus home composting, which garment packaging formats genuinely qualify, and where claims on print and web copy cross the line. Material selection is out of scope here — see the eco bag guide linked at the end.

1. Degradable, Biodegradable, Compostable: Three Words, Three Legal Meanings

Degradable only means the material breaks apart — fragments can be invisible and still be plastic. The EU has banned oxo-degradable plastics since 2021, so bags made from them cannot enter the European market. Biodegradable means conversion by micro-organisms into water, CO2 and biomass, but with no time limit and no residue requirement, which makes it almost unverifiable on its own. Compostable is the strict one: it must disintegrate on schedule, biodegrade completely, and leave a compost that is not phytotoxic.

When a buyer waves through a bag that says eco-friendly degradable, they are treating three words as one. The vaguer the claim, the more likely it is flagged as greenwashing at the destination port — and answering one greenwashing challenge usually costs more than the packaging premium in the first place.

2. Behind the Logo Is a Test Programme, Not a Sticker

Industrial composting most often cites EN 13432 in Europe and ASTM D6400 in the US, GreenPla in Japan, and in Australia AS 4736 for industrial plus AS 5810 for home. The core criteria are similar: under controlled composting, disintegration within roughly 12 weeks to no more than 10% residue on a 2 mm sieve; 90% biodegradation within six months; a phytotoxicity test on the finished compost where germination and biomass must not fall significantly below the control; and heavy metals under the limits.

Home compost certificates such as OK compost HOME test at lower temperatures over longer cycles and are considerably harder to pass, which is why few materials hold both. So when a buyer says compostable, establish industrial or home first: most European municipalities only collect for industrial composting, which leaves home-compostable bags with nowhere to go in practice.

3. Which Garment Packaging Formats Really Qualify

• Qualifies: thin inner bags for individual garments, the paper body of a hang tag, small sticker labels — provided wall thickness and formulation meet the disintegration criteria
• Marginal: mailer bags and paper carrier bags. Thicker material, higher cost, and load-bearing plus seal strength must be revalidated rather than carried over from the existing spec
• Does not qualify: packaging held in stock for more than a year. Strength and barrier performance of compostable film decline with time, so the bag fails first — not the garment
• Does not qualify: anything entering a PE recycling stream. Compostable plastics contaminate film recyclate and many recyclers explicitly refuse them

One more point gets missed: compostable bags are poor moisture barriers. Over forty days at sea, humidity builds inside, paper hang tags deform and self-adhesive labels lose tack. On export orders the compostable requirement and the moisture requirement often conflict, so the priority order needs agreeing with the customer rather than the factory choosing a material alone.

4. The Main Certification Schemes and Where They Are Accepted

5. How to Word the Claim: Print and Web Copy Are Governed the Same Way

Three working rules. First, only print the mark when you hold the certificate and are licensed to use it, and make sure the certificate number and licence match the actual production site. Second, state the composting route: industrial compostable, requires organic waste collection is far safer than compostable alone, because it names the precondition. Third, avoid unverifiable wording such as 100% degradable or fully biodegradable bag, and never present compostable and recyclable as the same thing.

Paper bags deserve extra care: the paper disintegrates, but lamination, handles, ink and adhesive may fail the disintegration and ecotoxicity criteria. Only the finished bag counts — testing the paper substrate alone convinces nobody, and it is the first thing an auditor probes.

6. The Six Pieces of Evidence a Buyer Will Ask For

• The certificate: standard, material grade or thickness range, issuing body, number and expiry
• Test reports: disintegration, biodegradation, ecotoxicity and heavy metals — a report missing any of the four is usually refused
• Licence: the logo licence, with certificate holder and actual production site matching
• Batch linkage: the grade used for the shipped lot must fall inside the certified scope
• Copy review: a record that packaging artwork and product page wording were reviewed and say the same thing
• End-of-life note: whether the destination country actually has composting collection — if not, the compostable claim should not be made

Related Articles

• Trims FAQ: all articles
• Eco Bag Options: Degradable, Recycled or PLA
• Designing Apparel Packaging for Recyclability
• EU Green Claims and Apparel Label Compliance