UK supermarket chain Tesco has dropped ‘eco-friendly’ carrier bags after evidence suggests they are doing more harm than good. Oxo biodegradable bags are made of non-renewable plastics, which are able to degrade in the presence of oxygen and sunlight thanks to the addition of small amounts of metals. Last year Tesco handed out over two billion oxo biodegradable bags to customers, but now the supermarket giant has had a re-think and stopped using the bags because they may be worse for the environment than conventional carriers.
“We’ve been putting pressure on the supply chain for several years to consider the negative impacts of oxo biodegradable bags and move to more environmentally-friendly alternatives,” said Dr John Williams, Head of Materials at the NNFCC. “Plastics are excellent materials, highly functional and energy efficient. Promoting sensible and certified routes to reuse, recycle and dispose of plastics, will improve sustainablility. Artificially accelerating the degradation of an oil-based plastic is neither economically or environmentally sensible.”
Tesco’s decision follows research by the UK Department for Environment, Food and Rural Affairs (Defra), which cast doubts over claims that the bag would degrade to water, carbon dioxide and biomass in just 18 months. Defra’s report concluded that degradability would depend on where and under what conditions the bag ended up after use. Certainly not an antidote to plastic littering as some producers claim. In landfill an oxo biodegradable bag won’t degrade at all because there is no light or oxygen, and these materials also cause problems in recycling streams according to the European Plastics Recyclers Association.
A spokesman for Tesco said, “We took the decision to remove the biodegradable additive because we believed it contributed towards bags becoming weaker and to help better promote their re-use and recycling at end-of-life.” “This decision was underpinned by a detailed review of the science to help us understand the full life-cycle environmental impacts of our carrier bags.”
New Tesco bags are not biodegradable but instead contain 15 per cent recycled material.
Source: NNFCC, 2011-08-16.