October 18/Lowell, Mass./Lowell Sun -- Responding to health concerns about possible carcinogens in the former polystyrene containers, Stonyfield Farm Inc. announced it has switched to a plastic made from corn -- one of the first plant-based containers for the dairy industry and believed to be the first for yogurt.

Polyactic acid or PLA, a polymer made from corn, is nothing new. Last April, Frito-Lay came out with a compostable bag for its SunChips, one which it is now scrapping for most varieties because customers complained about how noisy it was. Coca Cola Co. has introduced a bottle made from up to 30% plant-based materials and a mix of petroleum-based materials.

Stonyfield admits while its PLA package is made from a renewable source and not fossil fuels, it is not perfect -- because of the energy, pesticides and genetically modified seeds that go into growing the corn, which is also a food source. In addition, there is only one U.S. facility that recycles PLA.

To offset the use of genetically modified corn, Stonyfield is paying corn growers in Nebraska extra to grow corn without genetically modified seeds and following certain environmental standards, but that corn is not necessarily going into the cups, because keeping it separate would have been too expensive, Stonyfield said.

"So we're moving farmers off of GMOs and to better standards to meet our needs but that plastic might not actually be in our cup," Hirshberg said.

That is not only novel but could have significant environmental impacts if other companies come on board, said Anne Johnson, director of the Sustainable Packaging Coalition, an industry working group.

"In addition to the package itself, it's following through really to the source of the feedstocks for their packaging and trying to make sure there is best practice there," she said.

Stonyfield also has done its homework. Through a life cycle study of the packaging, it found that PLA is a better option than polystyrene, in terms of energy use, greenhouse gas missions and human health, said Nancy Hirshberg, Stonyfield's vice president of natural resources.

The Londonderry company has tinkered with its packaging over the years, reducing the amount of material going into it and replacing the plastic lid on certain containers with foil. In the latest shift, it is not changing its other containers, which are polypropylene and polyethylene.

The Stonyfield multipack cups are not compostable and not recyclable yet, because only one U.S. facility that recycles PLA, but Stonyfield hopes to change that.

The move toward more sustainable practices has been business-driven, Johnson said.

"Sustainability is a license to operate in this day and age," said Johnson.

From the November 1, 2010, Prepared Foods E-dition