The Anaerobic Digestion & Bioresources Association (ADBA) and Renewable Energy Association (REA) have urged local authorities to do more to keep problematic types of plastic out of food waste collections.
A joint document published by the two trade bodies said AD operators and composting plants needed to work closely with councils over the use of caddy liners.
It said: “Where food waste is collected for recycling this will include what type of caddy liners are acceptable, how quality will be monitored and how to improve feedstock quality.
“Where the food waste is going to AD, having consulted with their recycling plant, local authorities may specify conventional plastics rather than compostable plastic caddy liners.”
The document, which is part of the part of the Food Waste Recycling Action Programme, also covers steps that operators, local authorities and the packaging industry can take to help achieve plastics-free composts and digestates.
Jeremy Jacobs, REA technical director, said there was an urgent need to tackle plastic pollution in soils, rivers and seas.
“As an industry we are committed to producing digestates and composts of the highest quality,” he added.
“We would like to see more local authorities communicating - via whichever channels are most effective - what can be put in their food, garden or food and garden waste bins.
“Waste collection contracts are the first link in the chain. With so many local authorities ones coming up for renewal in the next few years it’s important that those covering biodegradable waste composting and digestion specify the type of bin liner allowed, acceptable level of contaminants, financial penalties, and the right of the facility operator to reject any doubtful delivery.”