The complete guide
Compostable bags explained: what actually breaks down and what doesn’t
"Biodegradable" and "compostable" get used almost interchangeably in casual conversation, but they mean genuinely different things — worth understanding before choosing a caddy liner.
Biodegradable vs compostable: the actual difference
"Biodegradable" is a loosely regulated term that can technically apply to anything that eventually breaks down, even if that takes decades and leaves microplastic fragments behind. "Compostable" is a more specific, and in the case of certified products like this one, independently verified claim: the material fully breaks down into water, CO2 and biomass (humus) within a defined timeframe under composting conditions, leaving no toxic residue or persistent fragments. Certification under EN 13432 or ASTM D6400 means a product has actually been tested against those specific criteria, not just labelled optimistically.
Why the certification numbers matter
EN 13432 is the European standard for packaging recoverable through composting, and ASTM D6400 is its US equivalent — both require independent lab testing confirming the material disintegrates and biodegrades within set timeframes without leaving harmful residue. A bag carrying both certifications, like GreFusion's, has cleared two separate, rigorous testing regimes, which is a meaningfully stronger claim than an uncertified bag simply labelled "eco-friendly" or "biodegradable" with no testing standard behind it.
What 180 days in a standard compost pile actually means
The 180-day figure assumes the bag ends up in an active composting environment — whether that's a home compost heap, a council food waste collection that processes to industrial composting standards, or (for the electric composters in this collection) mixed into finished output that later goes into outdoor composting. A compostable bag sitting in a normal landfill won't necessarily break down on the same timeline, since landfill conditions differ significantly from active composting conditions.
Using liners with an electric composter vs a traditional compost pile
If you're using a caddy liner to collect scraps before feeding an electric composter (like the units elsewhere in this collection), check the liner is compatible with the composter's processing cycle — some electric units are designed to process food waste alone without a liner bag included, so use the caddy liner for kitchen collection and empty the contents directly into the composter rather than adding the bag itself unless the manufacturer confirms it's compatible.
Storage and shelf life
Compostable bags are designed to start breaking down under composting conditions specifically — warmth, moisture and microbial activity — not simply from time in a drawer. Stored in a cool, dry place away from direct sunlight, a pack of unused liners has a reasonably long shelf life before use, though it's sensible to use them within a year or two of purchase for best performance.