Research note · Compostable materials
Home compostable plastics under real conditions
Citizen-science research examined whether people could identify compostable packaging and whether those materials disintegrated successfully in home compost.
Publication overview
A label is only one part of the system.
Compostable and biodegradable plastics are increasingly visible in packaging, but their environmental performance depends on identification, collection and appropriate treatment—not the material description alone.
The study used a citizen-science approach through The Big Compost Experiment. It involved 9,701 participants across the UK and considered their capability, opportunity and motivation to recognise and process packaging described as home compostable.
Within that wider group, 1,648 participants conducted home-composting experiments. Their observations helped researchers examine the types of plastic tested and the extent to which items disintegrated under varied, real household composting conditions.
Identification was a central challenge
The research found uncertainty around the meaning of “compostable” and “biodegradable” labels. Among the sampled packaging, 14% was certified only for industrial composting, while 46% displayed no compostability certification. These distinctions matter because industrial facilities operate under controlled conditions that a household compost system may not reproduce.
Performance varied at home
Most biodegradable and compostable plastics tested did not fully disintegrate across the home-composting conditions observed. That included 60% of items carrying home-compostable certification. The finding illustrates why certification, user instructions and real treatment conditions must be considered together.
Editorial context: The publication indicates that home composting should not be treated as a generally effective processing route for biodegradable or compostable packaging in the UK. Suitability needs to be assessed for the item, certification and available waste system.
The full study provides its methods, analysis and limitations in greater detail. Read the paper.