Stonyfield Farm announced today that it has converted from petroleum-based plastics to a plant-based material to form its multipack yogurt cups. It had been using polystyrene PS #6 plastic, which is derived from petroleum. The change affects the 200 million cups produced annually by the Londonderry, N.H.-based dairy processor. Neither the larger containers for yogurt nor the packaging used for the company’s other dairy products are affected by the change.

Stonyfield is using a plastic made of polylactic acid (PLA) extracted from corn. Multipacks of yogurt made from the material are already on grocery shelves. The bottom of each cup is stamped “This cup is made from plants.” Stonyfield converted to PLA earlier this year. Nancy Hirshberg, the company’s vice president of natural resources, told Dairy Foods that the cups are thinner but denser.

Use of the plant-based plastic reduces Stonyfield’s carbon footprint by 1,875 metric tons of CO2 annually which equals the emissions from 4,360 barrels of oil, according to an analysis by a professor at the University of California, Santa Barbara. If the entire dairy industry replaced polystyrene containers with plant-based plastics, carbon dioxide emissions can be reduced by 671,234 metric tons annually (equal to the emissions from 1.5 million barrels of oil). Stonyfield ranks 50th on Dairy Foods list of largest dairy processors.

The entire four-cup multipack, which includes labels and lids, is 81% bio-based and 19% petroleum-based, Stonyfield says.

NatureWorks, Minnetonka, Minn., a subsidiary of Cargill, makes the material, called Ingeo PLA. Clear Lam Packaging, Elk Grove Village, Ill., mixes colorings and other additives into the material to create rolls of plastic, which it ships to Stonyfield. The dairy processor then forms it into cups. Previously, Stonyfield was purchasing cups from a vendor that shipped to New Hampshire, but by producing its own cups, Stonyfield has eliminated a stop on the supply chain and further reduced its carbon footprint.

Stonyfield retrofitted existing form-filling equipment to accommodate the rolls of plastic. One effect of the new material is that it dulls the blades on the filler more quickly.

The Institute for Agriculture and Trade Policy, Minneapolis, and its Working Landscape Certificate program seeks to reduce the environmental impact of corn and other crops grown for industrial purposes. The Working Landscape program pays two farmers who are producing corn to Stonyfield’s specifications, which include no genetically modified corn and prohibitions on certain pesticides and fertilizers. Because the approximately 500 acres of corn are produced in an offset program, Stonyfield can’t claim that the PLA comes specifically from these farms. It can, however, state that 500 acres were farmed according to sustainable principles.

Environmental benefits of PLA derive from the reduction in material needed rather than composting or recycling cups, Hirshberg says. The rim of the cup is too thick to be compostable, and composting would release more CO2. The infrastructure is not in place to make recycling an option. Although there are two PLA recycling centers-one in Wisconsin and the other in Belgium--the Wisconsin facility cannot separate paper labels, adhesives and lidding from the PLA cups.

Hirshberg told Dairy Foods that PLA from corn is a “transitional” technology and that Stonyfield will continue to evaluate new green processes as they become available.

Attend a Stonyfied Webinar Today

Nancy Hirshberg leads two webinars today about Stonyfield Farm's use of PLA plastic packaging.

Wednesday, Oct. 13, 11 a.m. - noon (ET
Event address for attendees:
Event number: 663 424 988
Event password: 1111
Teleconference: Call-in toll-free number (US/Canada) 1-877-669-3239 Access code: 663 424 988

Wednesday, Oct. 13, 2-3:00 p.m. (ET)
Event address for attendees:
Event number: 667 925 648
Event password: 1111
Teleconference: Call-in toll-free number (US/Canada) 1-877-669-3239