Carton supporters argue they are lighter than cans, and due to their square shape can be packed together more tightly during transportation and on shelves. They also boast strong environmental credentials. The cartons used for Sainsbury's standard and Basics tomatoes made by Tetra Pak and SIG Combibloc respectively have FSC chain of custody certification proving the wood fibre is sourced from sustainably managed forests.
Stuart Lendrum, Sainsbury's head of packaging, says the move will reduce carbon emissions by 156 tonnes a year, as fewer lorries are required to transport them, and may herald the use of more cartons. "This type of carton is a strong challenger to the traditional tin can," he says.
However, there remains one chink in the carton's green armour. While great strides have been made to increase local authority collection of cartons for recycling, it is still not possible to reprocess them in this country. Cartons are shipped to Sweden for reprocessing. "At the moment, reprocessing them in this country is not economically viable," says Cindy Haast, SIG Combibloc marketing manager, North Europe. And whereas cans can be endlessly recycled back into cans, cartons are not recycled back into cartons, meaning each new carton must be made from new materials.
"Sainsbury's claims the repackaging is part of a drive to become more eco-friendly but it has seemingly failed to consider recycling rates. In the UK, two thirds of food cans are recycled," says Nick Mullen, director of the Metal Packaging Manufacturers Association.
He isn't the only one to question the carton's superiority. Schools in South Wales, which previously used individual cartons for children's milk, have switched to recyclable plastic bottles supplied by Nampak.
So, the carton may be winning the battle on one front but it needs to watch its back on another and thanks to its recyclability, the can could yet win the war.
Focus On Packaging