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, according to a Guardian study. The substitutes can increase emissions of greenhouse gases on landfill sites, some need high temperatures to decompose and others cannot be recycled in Britain.
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 20-30% a year.
The industry, which uses words such as “sustainable”, “biodegradeable”, “compostable” and “recyclable” to describe its products, says bioplastics make carbon savings of 30-80% compared with conventional oil-based plastics and can extend the shelf-life of food.
Concern centres on corn-based packaging made with polylactic acid (PLA). Made from 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 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 114m PLA containers over the course of a year.
While PLA is said to offer more disposal options, the Guardian claims that it will barely break down on landfill sites, and can only be composted in the handful of anaerobic digesters which exist in Britain, but which do not take any packaging. In addition, if Pla is sent to UK recycling works in large quantities, it can contaminate the waste stream, reportedly making other recycled plastics unsaleable.
The whole article by The Guardian can be read here
Source: The Guardian, 2008-04-26.