Supermarket launches biodegradable plastic bag

According to the Co-op, the average English person uses 134 bags every year – that’s 323 bags per household, which on average are discarded after only three minutes. In the UK the grocery industry uses enough bags to carpet the entire planet twice a year.

The new degradable carrier bag, produced by plastics firm Symphony Environmental, has initially been launched at only selected stores and replaces lighter-weight bags given away for free at the checkout. But if all goes well, the bag could be available in all Co-op stores by the end of the year, a spokesman for the company told edie. The supermarket already offers ‘a bag for life’ – a stronger carrier bag.

The Co-op is keen to point out that their new carrier is just as strong as a conventional plastic bag, but whereas the latter takes 100 years to decompose, the new bag starts degrading in 18 months and will have completely degraded in three years. All that remains will be carbon dioxide, water and a small amount of mineralisation originating from the oil used to produce the plastic.

Tom Robinson, Head of Retail at Symphony Environmental and inventor of the ‘bag for life’ concept – which can save up to 25 carrier bags – told edie that the technology used for the Co-op’s bags can be adapted for a host of different plastic applications. “We put a flaw in the molecular structure,” he explains. This means that plastic products could be programmed to begin to degrade after a predetermined length of time – anywhere between six weeks and 60 years. After this initial period of usefulness the rate of decomposition will depend predominantly on exposure to sunlight, but also to rainfall and temperature, with decomposition occurring faster in countries such as Saudi Arabia and slowest in countries such as Greenland.

For example, Symphony has produced a plastic food packaging for supermarket chain Sainsburys that degrades in half the amount of time taken for leaves to decompose. However, the technology could also be used in heavier plastics such as computers and car components.

The Co-op isn’t the only company to have taken a shine to Symphony’s technology. Two further large retailers will be trying out the carrier bag in the next few weeks, with two more coming on board before the end of the year, Robinson told edie. This will result in Symphony producing one billion of the UK’s carrier bags. The company is also going to be signing a major food supplier before the end of the year.

“Our agreement with the Co-op is a significant first step in the introduction of degradable plastics to UK grocery consumers,” said Robinson. “The fact that the Co-op is pioneering the use of degradable carrier bags is testament to its genuine concern for the environment and its commitment to tackling the considerable problem of plastic waste.”

Symphony carrier bags also appear to be developing a following outside the UK, with companies from Germany, France, Spain and Ireland already using them. By this time next year, Symphony will be producing 3.4 billion carrier bags globally, said Robinson. Banana producer Fyffes also uses Symphony’s technology for all the plastic used in the growing, packaging and transport of its fruit.

But, in the best of all worlds, the use of carrier bags – and therefore resources – needs to be reduced. The Co-op agrees. “We would be quite happy to see the introduction of a tax for carrier bags,” the company spokesman told edie (see related story).