Courtesy The Coca-Cola Company

Many companies are using plant-based packaging for their products, including The Coca-Cola Company, which created the PlantBottle.

Cruise the grocery aisle and many products you’re familiar with might appear to be the same tried-and-true products you’ve always known. Chances are good, though, that their packaging has gotten a makeover.

Manufacturers of popular brands like Coca-Cola, SunChips, Stonyfield Farm and Newman’s Own Organics have made the switch from plastic containers to plant-based packaging.

According to market research firm EL Insights, 27 percent of products sold at major U.S. retailers were made with sustainable packaging in 2010. That number is expected to increase to 37 percent by 2011.

“Environmental groups have done a great job of telling companies that we don’t like their toxic plastic and petroleum products,” says Stephanie Barger, executive director of the Earth Resource Foundation, an environmental educational nonprofit organization. “There is more awareness [of the dangers of plastic] and efforts to reduce its use.”

Those efforts appear to be working. Stonyfield Farm estimates that swapping the petroleum-based cups for its multipack yogurt products helped cut its greenhouse-gas emissions by 48 percent. Coca-Cola introduced PlantBottle, a recyclable bottle partially made from sugar-based ethanol that reduced the company’s petroleum use by 79,000 barrels in 2010.

But plastic containers aren’t the only packages receiving a plant-based makeover.

Frito-Lay began packaging SunChips in bags made from 90 percent plant-based materials in 2010. According to the company, the bags are compostable and will completely break down in an active compost pile in 14 weeks. (If the bags are sent to the landfill, they will decompose eventually, but the process is not as efficient.)

Plant-based packaging is made from polylactic acid, or PLA, a compostable polymer made from starch, including corn and sugarcane.

The advantages to PLA packaging include the obvious switch from petroleum to plant sources, which requires less energy and releases fewer greenhouse gases during the manufacturing process. The crops used to make PLA capture carbon as they grow, which offers an additional benefit to plant-based packaging.

One of the biggest concerns about PLA packaging, however, is whether it lives up to the eco hype.

Stonyfield Farm replaced non-recyclable polystyrene plastic packaging with plant-based yogurt cups, but the PLA products are not recyclable or compostable in most communities. According to the Stonyfield Farm website, the technology to recycle the plant-based containers is too limited to be feasible. Composting isn’t an option either.

In order for PLA packaging to biodegrade, it needs to be in a controlled composting environment, according to the Biodegradable Products Institute. Backyard compost bins do not fit the bill. PLA packaging needs to be sent to large-scale composting facilities in order to break down—and most people don’t have access to such facilities, which means plant-based packages end up in the trash.

Even if the cups could be composted, it might do more harm than good. A statement on the Stonyfield website reads:

 “… the independent review of PLA’s environmental impact found that composting is not the best option for disposing of the cups … it would release the carbon dioxide (CO2) in the plant-based plastic (CO2 absorbed by the corn when it was growing) back into the atmosphere where it would contribute to global warming.”

The other issue is that most PLA packaging is manufactured from corn. According to the USDA’s Economic Research Service, up to 70 percent of corn grown in the U.S. contains genetically-modified organisms, or GMOs, which raises concerns about environmental damage, impacts on wildlife and the potential for GMO crops to pollinate organic crops.

“It takes a lot of fertilizer, pesticides and water to grow these crops,” Barger says. “Switching to bio-plastics [like PLA] opens a Pandora’s box.”

Barger also worries that manufacturing single-serving containers, even if they’re made out of plant materials, perpetuates a disposable culture.

“We need to stop using single-serving, disposable packages—no matter what they’re made of,” she says. “Our goal is to work toward zero waste, not change the type of waste.”