Biodegradable bags may not be as green as they seem

As though the paper-or-plastic question weren't vexing enough, now some retailers are finding that the "biodegradable" plastic bags they'd hoped would please green shoppers might not be so Earth-friendly after all.

Lunds and Byerly's recently replaced its plastic bags with a biodegradable bag made of low-density polyethylene that purportedly breaks down when exposed to sunlight, oxygen, soil, moisture and microbes.

But biodegradable bags are still petroleum-based, and while they do break down into smaller particles, chemicals eventually show up in the food chain and our bodies, according to Susan Hubbard, CEO of Eureka Recycling in Minneapolis. And it's unclear whether biodegradable bags can be recycled.

What's a shopper to do?

"I don't like plastic bags, so [the grocery store] is in a sense forcing me to bring a reusable bag," said Gail Hanson of Minneapolis, who was shopping at the northeast Minneapolis Lunds that only offers plastic bags, not paper. She keeps reusable bags in the front seat of her car so she remembers to take them into the store.

Although a recent attempt to mandate plastic bag recycling in Minnesota did not survive a legislative committee, pressure to cut back or eliminate the use of plastic bags has been building in the United States and around the world.

In 2007, San Francisco became the first city in the country to ban plastic shopping bags, and similar measures have been adopted or enacted in cities as diverse as Phoenix, Portland, Ore., and Boston. Seattle is debating a fee on plastic bags in hopes of encouraging shoppers to carry reusable bags, and several large stores including Ikea have either banned or begun charging for plastic bags.

Other countries, including China, have banned the distribution of free bags.

1 percent of bags are recycled

Biodegradable bags from Lunds and Byerly's are currently being recycled, but if that changes, Lunds and Byerly's will consider, well, bagging them.

"Our goal is still to be a more eco-friendly retailer," said Aaron Sorenson, spokesman for Lund Food Holdings Inc. The manufacturer of the stores' bags says they break down in two years in a landfill, and are 100 percent recyclable.

Americans use more than 90 billion plastic bags per year, but only about 1 percent of polyethylene plastic bags are recycled, according to the Environmental Protection Agency. Minnesotans recycle about 5 percent, the Minnesota Pollution Control Agency (MPCA) said. The rest wind up in landfills or on the landscape, where each may take hundreds of years to degrade, although estimates vary depending on the plastic.

So retailers like Lunds and Byerly's and consumers try to do the right thing -- though it can be frustrating figuring out what that is.

Roundy's, owner of Rainbow stores, chose not to use biodegradeable bags because store officials were told the bags cannot be mixed with other plastic bags for recycling, said Vivian King, director of public affairs at Roundy's.

(The Star Tribune is considering using biodegradable plastic bags for newspaper home delivery.)

Virginia-based manufacturer Trex Industries, which makes the Twin Cities' recycled plastic bags into plastic decking and lawn furniture, is doing a study to see if the biodegradable material compromises the product. If biodegradable material disintegrates when exposed to air and light, it might not make durable patio furniture, said Ginny Black, organics recycling coordinator at the MPCA.

The greenest bag

For all the hubbub over bags, there are shoppers who don't want plastic to go away, according to spokespeople at Cub, Rainbow, Target and Lunds/Byerly's. Consumers like the bags for frozen and deli items, and they use them for pet waste and garbage.

So while some supermarkets grapple with a so-called "greener" plastic bag, other retailers are charging for them or banning them to encourage use of reusable bags, which environmental experts say are the best choice.

When Ikea started charging a nickel for its plastic bags a year ago, the Swedish retailer expected bag use to drop 50 percent. Actual bag use plunged a surprising 92 percent, from 70 million to 6 million. In October the company will eliminate plastic and paper bags entirely.

Aldi supermarkets charge a nickel for paper and a dime for sturdy plastic bags that can be reused. The German company has charged for bags since it opened U.S. stores in 1976.

But mainstream grocery stores aren't likely to follow the lead of Mississippi Market Co-op in St. Paul, which eliminated plastic bags completely last month. Supermarkets don't want to alienate their customers, said supermarket analyst David Livingston.

"If you're buying a lot of groceries, reusable bags are cumbersome," Livingston said. "Stores should give away reusable bags if they want people to use them."

Many stores have done just that, or at least offered them at a discount. Stores that continue to offer plastic can look greener by highlighting their low-cost reusable bags. Cub Foods will offer a reusable bag free with a $25 purchase this week . Trader Joe's discourages use of paper or plastic by letting customers who bring their own reusable bags put their names in a drawing for prizes.

Target offers three sizes of reusable bags for 99 cents to $1.49. It does not currently collect plastic bags for recycling in its Minnesota stores but does so in California, Rhode Island and Maine to comply with state laws, said Target spokeswoman Amy VanWalter.

What about paper bags? Unlike plastic bags, paper is a renewable, compostable resource. Another alternative is a compostable bag made from corn starch, but those are about four times more expensive than plastic. Unfortunately, we can't plant forests fast enough to replace paper bags that are used only once, so put reusable bags in the car, Hubbard advised.

"Paper bags have always been a better choice than plastic," Hubbard said. "But reusable bags are the best choice."

John Ewoldt • 612-673-7633