Compostable bags can’t be composted, minister admits

Baroness Bennett said most people would be shocked to learn they can’t compost the majority of compostable-branded plastic

A minister has admitted that most plastic bags and packaging labelled ‘compostable’ can’t actually be composted.

Green peer Natalie Bennett pressed Lord Benyon, a minister for the Department for Environment, Food & Rural Affairs, on whether this type of plastic is a green “con”.

Lord Benyon told peers: "Compostable plastics must be treated in industrial composting facilities to be broken down and, when processed incorrectly, can be a source of microplastics and contaminate recycling streams.”

Lord Benyon added the government’s focus would be on “reducing unnecessary consumption”, and creating a circular economy, reports the Mirror.

Baroness Bennett said: “The government talks about reducing single-use plastics, but Brits only have to look around them to see masses of the stuff in shops and cafes - and all too often, littering our streets.”

She also said most people would be shocked to learn they can’t compost the majority of compostable-branded plastic and called the compostable plastic debacle “just one more area of Tory policy chaos.”

Friends of the Earth campaigner, Camilla Zerr, said: “These are encouraging words from the minister. The focus should be on reducing plastic in the first place, not false solutions like compostable plastic.

“Replacing one single-use material by another doesn’t tackle the systemic problems of the overproduction and overconsumption of single-use products.

“The government now needs to match its words with action by doing far more to cut the amount of plastic waste produced in the first place and developing comprehensive policies that encourage widespread reuse and refill.”

According to the Big Compost Experiment, compostable plastics are a subset of biodegradable plastics that are designed to break down under controlled environmental conditions into water, biomass, and gases such as carbon dioxide and methane.

But most plastics marketed as compostable are anything but, with as much as 60% failing to disintegrate after six months, according to research from the University College London’s Plastic Waste Innovation Hub.

Prof Mark Miodownik, an author of the paper, said: “The bottom line is that home compostable plastics don’t work.”