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Bio-plastic proving not so eco-friendly

The worldwide effort by supermarkets and industry to replace conventional oil-based plastic with eco-friendly “bioplastics” made from plants is causing environmental problems and consumer confusion.

The substitutes can increase emissions of greenhouse gases on landfill sites, some need high temperatures to decompose.

Many of the bioplastics are also contributing to the global food crisis by taking over large areas of land previously used to grow crops for human consumption.

The market for bioplastics, which are made from maize, sugarcane, wheat and other crops, is growing by 20 percent to 30 percent a year.

The industry, which uses words such as “sustainable,” “biodegradeable,” “compostable” and “recyclable” to describe its products, says bioplastics make carbon savings of 30 percent to 80 percent compared with conventional oil-based plastics and can extend the shelf-life of food.

Concern centers on corn-based packaging made with polylactic acid (Pla). Made from genetically modified (GM) crops, it looks identical to conventional polyethylene terephthalate (Pet) plastic and is produced by US company NatureWorks.

The company is jointly owned by Cargill, the world’s second-largest biofuel producer, and Teijin, one of the world’s largest plastic manufacturers.

Pla is used by some of the biggest supermarkets and food companies, including Wal-Mart, McDonald’s and Del Monte. It is used by Marks & Spencer supermarkets in the UK to package organic foods, salads, snacks, desserts, and fruit and vegetables.

It is also used to bottle Belu mineral water, which is endorsed by environmentalists because the brand’s owners invest all profits in water projects in poor countries. Wal-Mart has said it plans to use 114 million Pla containers over the course of a year.

While Pla is said to offer more disposal options, it will barely break down on landfill sites, and can only be composted in anaerobic digesters, which do not take any packaging. In addition, if Pla is sent to recycling works in large quantities, it can contaminate the waste stream, reportedly making other recycled plastics unsaleable.

Last year the British company Innocent drinks stopped using Pla because commercial composting was “not yet a mainstream option.”

Anson, one of Britain’s largest suppliers of plastic food packaging, switched back to conventional plastic after testing Pla in sandwich packs. Sainsbury’s supermarkets has decided not to use it, saying Pla is made with GM corn.

“No local authority is collecting compostable packaging at the moment. Composters do not want it,” a spokesman said.

The bioplastics industry expects rising oil prices to help it compete with conventional plastics, with Europe using about 50,000 tonnes of bioplastics a year.

Concern is mounting because the new generation of biodegradable plastics ends up on landfill sites, where they degrade without oxygen, releasing methane, a greenhouse gas 23 times more powerful than carbon dioxide. Last week the US National Oceanic and Atmospheric Administration reported a sharp increase in global methane emissions last year.

“It is just not possible to capture all the methane from landfill sites,” said Michael Warhurt, resources campaigner at Friends of the Earth. “A significant percentage leaks to the atmosphere.”

“Just because it’s biodegradable does not mean it’s good. If it goes to landfill it breaks down to methane. Only a percentage is captured,” said Peter Skelton of Wrap, the UK government-funded Waste and Resources Action Programme. “In theory bioplastics are good. But in practice there are lots of barriers.”

Recycling companies said they would have to invest in expensive new equipment to extract bioplastic from waste for recycling.

“If we could identify them the only option would be to landfill them,” said one recycler who asked to remain anonymous. “They are not wanted by UK recycling companies or local authorities who refuse to handle them. Councils [local government] are saying they do not want plastics near food collection. If these biodegradable [products] get into the recycling stream they contaminate it.”

“It will get worse because the government is encouraging more recycling. There will be much more bioplastic around,” the recycler said.

Problems arise because some bioplastics are “home” compostable and recyclable.

“It’s so confusing that a Pla bottle looks exactly the same as a standard Pet bottle,” Skelton said. “The consumer is not a polymer expert. Not nearly enough consideration has gone into what they are meant to do with them. Everything is just put in the recycling bin.”

On Friday, NatureWorks accepted that its products would not fully break down on landfill sites.

“The recycling industry in the UK has not caught up with other countries” said Snehal Desai, chief marketing officer for NatureWorks. “We need alternatives to oil. UK industry should not resist change. We should be designing for the future and not the past. In central Europe, Taiwan and elsewhere, NatureWorks polymer is widely accepted as a compostable material.”

“It’s very early days,” said Reed Paget, managing director of Belu. “The UK packaging industry does not want competition. It’s shortsighted and is blocking eco-innovation.”

“People think that biodegradable is good and non-biodegradable is bad. That’s all they see,” said Chris Goodall, environmental analyst. “I have been trying to compost bags that are billed as ‘biodegradable’ and ‘home compostable’ but I have completely failed. They rely on the compost heap really heating up but we still find the residues.”
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