Packaging industry bodies have welcomed the long-awaited report from the Environment Agency, entitled Life Assessment of Supermarket Carrier Bags. It has found that ordinary high density polythene bags used by retailers are greener than supposedly low impact choices.
The report highlighted that HDPE bags are, for each use, almost 200 times less damaging to the climate than cotton hold-alls favoured by environmentalists, and have less than one third of the C0₂ emissions than paper bags.
The findings suggest that, in order to balance out the tiny impact of each lightweight plastic bag, consumers would have to use the same cotton bag every working day for a year, or use paper bags at least three times rather than putting them in the bin or recycling.
Most paper bags are used only once and one study assumed cotton bags were used only 51 times before being discarded, making them worse than single-use plastic bags.
On 20 February, The Independent on Sunday (20 February) obtained a copy of the report that was yet to be published. It stated that the EA said it did not have a date for publication, despite being commissioned in 2005 and scheduled for publication in 2007.
The report set out to find out which of seven types of bags have the lowest environmental impact by assessing pollution caused by extraction of raw materials, production, transportation and disposal.
It found that an HDPE plastic bag would have a baseline global warming potential of 1.57kg C0₂ equivalent, falling to 1.4kg CO₂ equivalent if re-used once, the same as a paper bag used four times (1.3kg CO₂e).
A cotton bag would have to be re-used 171 times to emit a similar level, 1.57kg CO₂e.
The new EA study contradicts research that Defra published last year, which found that plastics that incorporate additives to accelerate degradation were potentially damaging to the recycling stream and should be incinerated after use – while landfill was the second-best option.
Speaking to the Independent on Sunday, PAFA chief executive Barry Turner suggested that the Environment Agency had “suppressed” the report. He said: “This [report] has dragged on and on. It was a report that could have been done relatively quickly, probably within 12 months but it has gone on for years.”
He added that he would not be surprised if the report was buried because it “didn’t give the right answers” as it “doesn’t support the political thrust at the moment”.
He explained: “People at CEO level [retailers] have been consistently telling Wrap and Defra that they have been missing the point. They have had very closed ears on this and I have never been so rigid in their approach.”
Speaking to Packaging News, PAFA spokesman Peter Woodall added: “This analysis shows what we have been saying for years. Plastic bags are a more environmentally friendly option than cotton bags.
“I think this is going to be a major boost for the industry in terms of our own ability to be listened to. We have been talking about the science rather than the spin and no one has been listening. Now, this is an independent study supporting what we have been saying.”
British Plastics Federation director general Peter Davis commented: “The BPF are very pleased to see this Government research which shows that the plastic carrier bag has strong environmental credentials.
“This vindicates the hard work done by PAFA and the Carrier Bag Consortium to put over the real facts on the environmental benefits of plastic carrier bags.
“We hope this will now transform the debate to less of a knee-jerk reaction to a debate based on sound science and facts.”
An Environment Agency spokesperson said:
“A significant part of the environmental impact of these bags is associated with the resources used in their production. All multi-use bags need to be reused as much as possible to reduce their relative environmental impact and be responsibly recycled at the end of their life.
‘Plastic “bags for life” only need to be used a few times to have a lower environmental impact than single-use carrier bags.”