'Green' plastics may be worse for environment

A type of degradable plastic bag that was supposed to be better for the environment may not be completely biodegradable, a Government-commissioned study has found. The bag is made with metal salts that are supposed to accelerate degradation, but scientists found the material was not fully biodegradable and might contaminate the way plastics are recycled.

Hundreds of millions of plastic bags and packaging items have been produced by the process, and they are widely used by some of the leading British retailers, including Waitrose, Ocado, JD Sports, Accessorize, River Island and Tesco.

Plastics with the additives are meant to break down quickly and fully in the presence of light and air by a process called oxidative degradation. But the term biodegradable is "virtually meaningless" said the Loughborough University scientists who ran the study. "The bags cannot be composted and there are concerns about the effects of the plastic in recycling facilities," said the scientists, who added that the best way of disposal was incineration or landfill.