The study, commissioned by the Department for Environment, Food and Rural Affairs (Defra), said the oxo-bio plastics, that are used in packaging for consumer goods including cosmetics, as well as plastic bags, may not be as eco-friendly as consumers believe.
Loughborough University authored the report which has raised concerns about the impact of the plastics on the environment once they break down into smaller pieces.
Oxo-biodegradeable plastics rely on an additive that can break down the polymer chains in the plastic making them brittle, which speeds up the degradation process.
But the Defra-backed report not only “highlighted the uncertainty about the impact of the plastics on the natural environment when they begin to breakdown into smaller pieces”, it also warned that the plastics were “neither suitable for conventional recycling methods, due to the chemical additives, nor suitable for composting, due to the plastic not breaking down fast enough”.
Defra’s Environment Minister, Dan Norris said there was a risk consumers could be confused about the claims made by oxo-bio products, as he warned that incorrect disposal of oxo-bio plastics had “the potential to negatively affect both recycling and composting facilities.”
“We hope this research will discourage manufacturers and retailers from claiming that these materials are better for the environment than conventional plastics”, he added.
Industry response
However, Symphony, a UK manufacturer of oxo-bio plastics, rejected the report and questioned its objectivity – despite Defra insisting it had been independently and rigorously peer reviewed by recognised academics.
Quoting from the report, the company dismissed its claims that oxo-degradable plastics "do not improve the environmental performance of petroleum based plastics" and "marketing claims which are typically applied to such materials are potentially misleading."
“It should be obvious that plastic which self-destructs at the end of its useful life, leaving no harmful residues, is better for the environment than normal or recycled plastic, which can lie or float around for decades,” said a Symphony statement.
The company said that Loughborough University did none of experiments itself and it alleged that “two of the three assessors of the Report are themselves engaged in bio-based plastics, which is a totally different discipline to oxo- biodegradable”.