Sainsbury is going the whole hog with trials of what is believed to be the first fully biodegradable carrier bag made from the same starch that is found in Tapioca pudding.

Biodegradable material from a renewable source was chosen over the degradable plastics carrier bag solutions that have recently been adopted by retailers, including The Co-op and Somerfield.

Sainsbury packaging innovations manager Terry Robins said: “We think customers will love this bag. In contrast to “degradable” bags, which are slow to break down and may leave pieces of plastics and traces of harmful chemicals, the new Sainsbury’s bag biodegrades naturally and leaves no harmful residue.”

Environmental packaging specialist Biopac UK, based in Malvern, Worcestershire, produced the bags. They are said to be as strong as conventional bags and customers will be encouraged to re-use the carriers as normal until they wear out. The bag will only biodegrade when composted said a Sainsbury spokesperson.

Trials are now underway at Sainsbury stores in Islington, Ladbroke Grove and Durham and will take place over three months.

Biopac declined to comment until the trials are over.