Compostable, biodegradable and recyclable: what each word means

The words printed on a cup sleeve are doing a lot of work and very little of it is precise. Three of them come up constantly, they mean different things, and one is close to meaningless without qualification.

Biodegradable

Biodegradable means the material will eventually be broken down by microorganisms. It sets no time limit and specifies no conditions.

Almost everything is biodegradable given long enough. Without a timeframe and a defined environment, the word tells you nothing useful, which is exactly why it appears on so much packaging.

Treat “biodegradable” on its own as marketing. Treat “biodegradable in X conditions within Y days” as information.

Compostable

Compostable is the specific version. It means the material breaks down into water, carbon dioxide and biomass, within a defined period, leaving nothing toxic behind — and it is testable against a standard.

The important split is between two kinds of composting.

Industrial or commercial compostable means it needs the sustained high temperatures of a commercial facility. Most compostable cups are in this category. In a garden heap they will sit there largely intact.

Home compostable is a stricter standard: it breaks down at ambient temperatures in a domestic heap. Fewer products qualify, and where a maker claims it, they say so specifically.

The practical consequence: a compostable cup is only compostable if it reaches a facility that can compost it. In a general waste bin it goes to landfill like anything else, and in a recycling bin it is a contaminant.

Recyclable

Recyclable means the material can be reprocessed into new material — which depends entirely on what your local facility accepts.

Ordinary hot cups are the classic problem. They are paper with a thin polyethylene lining to stop them going soft, and that lining has to be separated mechanically. Facilities that can do it exist and are not universal.

A cup can therefore be genuinely recyclable and still not recyclable where you live. Both statements are true at once, which is why the labelling confuses everyone.

PLA and PHA linings

Two plant-based alternatives to the polyethylene lining turn up on this shelf.

PLA is made from plant starch. It is industrially compostable. In a home heap it barely moves, and in a plastic recycling stream it is a contaminant because it looks like plastic and does not behave like it.

PHA is produced by microbial fermentation and breaks down more readily in more environments, including some that PLA will not manage. It costs more, which is why fewer cups use it, and where a maker uses it they say so.

Neither lining changes how the cup behaves in use. Both hold a hot drink the same way.

Bamboo fibre

Bamboo fibre cups are paper cups made with bamboo pulp rather than wood pulp. Bamboo grows fast and regrows from the same root, which is the argument for it.

A bamboo fibre hot cup still needs a lining to hold liquid, so the same questions apply: what is the lining, and is it compostable. A bamboo cup with a polyethylene lining is a polyethylene-lined cup.

This is why our listings file bamboo fibre hot cups under disposable paper cups rather than under compostable ones unless the maker states a compostable lining. The material of the wall is not the material that matters.

Unbleached, and what it tells you

Brown kraft cups are unbleached. Bleaching is a process step that whitens; skipping it uses less process and gives a slightly stronger paper.

Unbleached is not the same as unlined, uncoated or compostable. A brown cup can be lined with exactly the same polyethylene as a white one. Colour tells you about the bleaching and nothing else.

What actually reduces waste

Reuse, by a wide margin. A reusable cup used a few dozen times outperforms any disposable, whatever the disposable is made of, because the manufacturing footprint is spread across all those uses.

The honest hierarchy is: reusable used many times, then disposable that reaches the right waste stream, then disposable that does not. Which is why this shop sells both halves rather than pretending one of them does not exist.

How we describe things

Where a manufacturer certifies a cup as compostable, the listing says compostable and says which kind where they state it. Where a manufacturer says only “eco-friendly”, the listing says what the cup is made of instead, because “eco-friendly” is not a specification.

The compostable and plant-based cups page holds the certified ones. Disposable paper cups holds the standard lined cups, including bamboo fibre. The reusable half of the shop is on the reusable tumblers and bamboo and wooden cups pages.