British food store and retail chain Tesco has opted to revert to standard polyethylene carrier bags and stops use of bags containing an additive that can help plastics oxo-degrade over time. Tesco says its decision is based on data showing these biodegradable bags actually are not very environmentally sustainable. For Symphony Environmental Technologies Plc, a supplier of such additives, the move appears driven more by concerns of profitability and less over environmental worries. And EPI, another supplier of these additives and the company whose additives had been used in Tesco's shopping bags, says Tesco's reasoning—that the additives were weakening the bags' strength— doesn't hold water.
Tesco began offering it customer degradable plastic bags in late 2005, and last year gave away about 2 billion of them. Additives in the polyethylene used to make the bags helps them degrade into water, carbon dioxide and biomass in 18 months or so, depending on conditions. The bags can be re-used as well. But a number of recent studies have questioned the environmental friendliness of oxo-degradable plastics, among them England's National Non-Food Crops Center (NNFCC), which has posted papers of the negative impact of the oxo-degradable bags such as that these do not degrade in composting centers....