Biodegradable packaging is not a material you can order by name. It is a pairing: a material route, and a disposal condition that has to exist where the pack is actually thrown away. A paperboard that carries an industrial compostability certificate will not break down in a garden heap, and a sheet certified for home composting may never be collected in a market that only runs industrial facilities. Getting the pairing wrong is not a small error. It means paying a premium for a claim that produces no environmental result in the market you are selling into, and failing the customer audit that checks the claim against the disposal route.
This article sets out the five material routes used in paper-based packaging, the grade each one can realistically reach, and the questions that fix the specification before an order is placed.
What the word commits you to
The two words are used interchangeably in sales conversation and they are not interchangeable in procurement. Biodegradable describes a process: the material is broken down by biological action. On its own it carries no time limit, no temperature and no statement about what is left behind, which is why a bare "biodegradable" claim cannot be checked. Compostable describes a standard: the material breaks down within a defined time, at a defined temperature, leaving no ecotoxic residue, as tested against a named specification. A compostable claim is falsifiable. A biodegradable one usually is not.
For a purchaser, the practical reading is this: if the requirement comes from a customer, a retailer or a regulation, they almost always mean compostable against a named standard. If the requirement is marketing language with nothing behind it, it usually says biodegradable. Ask which one is meant before quoting.
The two questions that decide the specification
Almost every mistake in this category comes from answering one of these and skipping the other.
- Where does the pack go when it is finished? Industrial composting collection, a home compost heap, anaerobic digestion, landfill, or open environment. This is not a preference — it is infrastructure, and it differs by country, by region and often by municipality.
- Which material route meets the grade that route implies? Once the disposal condition is fixed, the number of workable constructions usually drops to two or three, and sometimes to one.
If the answer to the first question is "landfill", the honest position is that no compostable claim delivers anything at the point of disposal. The pack may still be the right choice for other reasons, but the environmental argument is not one of them, and saying so up front prevents a customer discovering it later.
Which grade applies, and what it is worth
Four families of standard do most of the work in this market, and they are not ranked — they cover different conditions:
- EN 13432 — the European reference for industrial composting, and the standard behind the "seedling" mark.
- ASTM D6400 — the United States equivalent for industrial composting.
- TÜV OK compost HOME — home composting, which is a harder test because a garden heap runs cooler and less consistently than a commercial windrow.
- OK biodegradable WATER / SOIL — degradation in a watercourse or in soil, which is a different claim again, and not one that a compostability certificate supports.
The important consequence: an industrial certificate does not imply home compostability, and a home certificate does not imply that the material will survive a commercial process. A grade is only meaningful next to the condition it was tested in. How to read a claim, and what to request as evidence, is set out separately in our guide to reading a biodegradability claim.
Material routes and the grade each one meets
This is the table that fixes most specifications. Read the first column against the disposal condition you established above, then read the last column — that is where the enquiries usually go wrong.
| Material route | Composting condition it can meet | Barrier it gives | Food-contact maturity | Where it fails first |
|---|---|---|---|---|
| Uncoated paper and board | Home (OK compost HOME) and industrial | None against grease or liquid — a dry-goods barrier only | Very mature; the base sheet is the low-risk part of any construction | Any fatty or wet product: oil strike-through within minutes |
| Water-based coating | Industrial; some systems also certified home | Grease, and moderate moisture resistance | Mature and widely converted; the fluorine-free route | Heavy or long-contact fat; high-humidity storage can affect the coating |
| PHA coating | Industrial; marine and soil degradation also claimed for some grades | Grease, water, and a useful moisture-vapour barrier | Narrower supply base — ask for the grade, not the family | Cost and availability; converting settings cannot be copied from a polyethylene line |
| PLA film lamination | Industrial only — does not break down in a home heap | Strong grease and moisture barrier; heat-sealable | Mature as a film; the finished composite is the problem | Home composting and every non-industrial route; the film does not separate from the fibre |
| Starch-based pad core | Industrial; some grades certified home | Absorbency, not a barrier | Mature for absorbent pads | Wet strength and rewet under load; the grade has to match the tray |
Where each route fails first
The failure column deserves its own paragraph, because it is the part a sample will not show you.
Uncoated paper fails the moment the product carries fat. A chip, a pastry or a piece of cheese will strike through an uncoated sheet in the time it takes the pack to reach a shelf. Uncoated stock is the right answer for dry goods and for applications where the paper is an outer wrap, not a contact layer.
Water-based coatings move the failure to the extremes. They handle ordinary grease contact well and are the established fluorine-free route — the base technology behind our water-based coated paper range. What they do not do is hold back a long, heavy fat load, and they behave differently in sustained high humidity. Both limits should be tested against the real product, not a standard test oil.
PHA coatings are the strongest of the coated routes on barrier and the narrowest on supply. The grade matters more than the family name: two PHA grades can differ in how they convert and in which environments they degrade in. Ask for the specific grade and its certification rather than accepting "PHA coated".
PLA lamination is the clearest case of a route that is compostable on paper and not in practice. The film itself meets industrial standards, but a fibre-film laminate only composts if the film separates and degrades at the same rate as the fibre. In a home heap it does not, and the pack fails the condition most consumers assume.
Starch-based pad cores are mature where absorbency is the job — the biodegradable absorbent pad range is built on them. Their limit is mechanical: wet strength and rewet performance under a loaded tray, which is where a cheaper grade will show itself.
The same question, four different answers
The pairing changes shape with the form of the pack, and the four lines in this series each put the pressure on a different link in the chain.
Baking and food paper is the line where the base sheet is usually the answer and the coating is the risk. An uncoated bakery liner is compostable by default; the moment a release coating is added so the product does not stick, the claim moves onto that coating and has to be specified with it. The question to ask is not whether the paper composts, but whether the pack still releases without a coating that does not.
Paper bags follow the same logic with a different variable. The bag is compostable until something is added — a grease barrier, a lamination for moisture, or a full-coverage print. Each addition moves the claim one layer further from the paper, and the ink is the one most often forgotten.
Labels are the hardest case, because a label is already a multi-layer construction before anyone asks about disposal: face, adhesive and liner belong to three different material families, and the claim holds only if all three clear the same condition. The liner — usually removed before the pack reaches the shelf — is frequently the layer that blocks it.
Absorbent pads put the question in the core. The top sheet and the back sheet can both be chosen correctly and the pack still will not compost if the core is a superabsorbent polymer; and the reverse — a compostable core under a polyethylene back sheet — fails in exactly the same way.
The pattern is the same across all four, and it is worth stating once: the claim belongs to the finished article, not to the paper inside it. Whichever line the enquiry comes from, the answer has to be given per construction rather than per material.
Writing it into an enquiry
Six lines fix the specification, and any supplier should be able to answer all six:
- The disposal route that exists where the pack is sold, named by country and, where relevant, by facility type.
- The standard the claim has to be made against — EN 13432, ASTM D6400, OK compost HOME, or another named specification.
- The product: fat content, moisture, contact time and storage temperature.
- Which layer carries the barrier, and whether that layer is part of the compostable construction or an addition to it.
- Whether the pack will be printed, and with what ink system.
- Whether the customer will ask for the certification document, and for which grade.
Common misuse
- Using the two words as synonyms. "Biodegradable" without a standard is unverifiable, and a specification written that way cannot be enforced.
- Ordering a home-compost grade into a market with no home composting. The claim is true and delivers nothing.
- Assuming the base paper carries the claim. An uncoated sheet is compostable; add a coating and the claim belongs to the coating.
- Assuming PLA is home compostable. It is not, and the pack will not break down in a garden heap.
- Reading a compostability certificate as a soil or marine claim. Those are different standards and different tests.
FAQ
Is biodegradable the same as compostable?
No. Compostable means tested against a named standard for time, temperature and residue. Biodegradable only means the material breaks down by biological action, with no defined limit. Where a customer or regulation is involved, the requirement is almost always the stricter one.
Can coated paper still be compostable?
Yes, if the coating is chosen for it. Water-based and PHA coatings have certified grades; a polyethylene or wax coating does not. The question to ask is which coating, at which grade — not whether the paper is coated.
Will a compostable pack break down in landfill?
Not reliably, and not in a useful timeframe. Composting standards are tested under managed heat and moisture. A landfill is neither, so a compostable claim should not be used to justify disposal there.
What should we ask a supplier for?
The certification document for the specific material and grade, the standard it was tested against, and the disposal condition it covers. If a supplier describes a product as compostable but cannot name the standard, the claim is not yet a specification.
Browse the range
The four product lines this applies across are baking and food paper, eco paper bags, eco labels and fresh absorbent pads. Each carries a different version of the same question, and each is covered by its own article in this series.