Compostable vs biodegradable: what is the difference?

By the Compost Ready editors · Updated 12 October 2026

All compostable packaging is biodegradable, but not all biodegradable packaging is compostable. "Compostable" means the material passed a specific test for breaking down in a composting process within a set time. "Biodegradable" on its own promises neither a time nor a place.

The short answer

Think of biodegradable as the broad category and compostable as a certified subset of it. The European Commission defines compostable plastics exactly that way: biodegradable plastics designed to break down under controlled conditions, typically in industrial composting or anaerobic digestion facilities.

The difference matters because the word "biodegradable" has no clock attached. Wood biodegrades. So does a leather shoe. Without a standard, the label doesn't tell you whether a pack will be gone in eight weeks or eighty years.

Side-by-side comparison

What "biodegradable" really promises

Very little, legally speaking. A material is biodegradable if bacteria and fungi can turn it into water, carbon dioxide (or methane, without oxygen) and biomass. That includes plastics made from oil, and it includes materials that take decades in cold soil.

The Commission's 2022 policy framework on bio-based, biodegradable and compostable plastics flags the risk plainly: people who read "biodegradable" may assume the item disappears quickly anywhere, which can encourage littering. EU consumer law has since moved against vague green claims that aren't backed by recognised evidence.

One trap deserves its own mention. So-called oxo-degradable plastics contain additives that make conventional plastic crumble into small fragments. They were sometimes sold as biodegradable. The EU banned them under the single-use plastics directive, because fragmenting is not the same as biodegrading.

What "compostable" promises

In Europe, a packaging "compostable" claim usually points to EN 13432. Passing it takes four things:

• at least 90% biodegradation within six months, measured as carbon dioxide released compared with a reference material, in a test at 58 °C;
• disintegration, meaning at least 90% of the material passes a 2 mm sieve after twelve weeks in a composting trial;
• no harmful effect on the finished compost, checked with ecotoxicity tests;
• heavy metals and certain other substances below set limits.

So "compostable" is a far stronger statement then "biodegradable". It is still a statement about a composting plant, though, not about a hedge or a beach.

Industrial vs home compostable

Here is where many shoppers come unstuck. Industrial composting runs hot, turned and controlled. A home heap might sit at 20 °C for months and dry out in summer. A cup that vanishes in an industrial plant within weeks can still be recognisable in a garden bin a year later.

The Commission notes that Europe has a standard for industrially compostable packaging but none for home composting, because home conditions vary so much. Home-compostable claims therefore rest on private certification schemes or national standards. Under the new EU packaging regulation, Member States may require some items, such as tea bags and fruit stickers, to be home compostable as well as industrially compostable.

A practical rule: if the label just says "compostable", assume industrial only.

How to read the labels

We don't reproduce certification logos here, but you'll recognise them on packs. When you see one, check three things:

1. Which environment it names. Industrial, home, soil and marine are different claims with different tests.
2. The certificate number. Genuine marks carry a licence or certificate number you can look up in the certifier's public database.
3. Whether it covers the whole pack. A compostable tray with a conventional plastic lid film is not a compostable pack.

Be wary of claims with no standard at all: "eco-friendly", "planet-safe", "breaks down naturally". Under current EU consumer rules, generic environmental claims like these need recognised proof behind them.

How to dispose of each

Certified industrially compostable: put it in the food or bio-waste bin only if your local council says compostable packaging is accepted. Many collection schemes accept compostable caddy liners but not other compostable packaging, so check.

Certified home compostable: your own compost heap is fine, though thicker items will be slow. Tearing them up helps.

"Biodegradable" with no standard: general waste. It will not help a recycling stream, and there is no evidence it suits compost.

Never: litter, rivers, the sea, or the plastic recycling bin. Compostable plastics are not designed for mechanical recycling and can contaminate it.