Paper or Plastic

The Best Answer May be "Neither"

Each year, Americans use more than 100 billion plastic shopping bags, consuming an estimated 12 million barrels of oil. After a very short working life, these bags retire to landfills where they take 500 or more years to break down, or become litter that clogs storm drains and threatens marine wildlife. City governments that have passed or are considering plastic bag bans include Steamboat Springs, Colorado, Portland, Oregon, California cities San Francisco, Oakland and Santa Monica, Boston, and both Annapolis and Baltimore in Maryland. Consumers in these cities must use paper or bring their own bags.

A shopper in Annapolis, Maryland, site of a proposed plastic bag ban.

Sam Shropshire, a Democratic city council member in Annapolis, says that many city residents moved to the city to be close to Chesapeake Bay, which is being damaged by the 95 percent of plastic checkout bags that end up in landfills or the environment. "We intend to put a stop to it right here in Annapolis," he says. Large chains will have six months to stop using plastic; smaller companies nine months. Merchants can substitute 100 percent recycled paper bags for the banned plastic.

According to Reusablebags.com, four of five shopping bags are made from plastic, and the average American family accumulates 60 of these "free" bags in only four trips to the grocery store. More than 90 percent of plastic bags are simply thrown away. Arthur Liu, account executive at EPI Environmental Products, says the plastic bags in landfills take up space and don’t allow food and other garbage inside them to break down with the help of oxygen.

"Plastic is still pretty new, and a lot of [plastic bags] manufactured half a century ago are still around," he says. Neil Seidman of the Institute for Local Self-Reliance says "Accumulating plastic is destroying our rivers and oceans."

In the debate between paper and plastic, however, the real answer may be neither. Reusablebags.com President Vince Cobb says that paper bags are also resource- and energy-intensive. According to his site, paper bag production generates 70 percent more air pollution than plastic, and while paper bags are recycled at a higher rate than plastic, 91 percent less energy is needed to recycle a pound of plastic than a pound of paper.

"I wanted to know, paper or plastic?" Cobb says. "But that question doesn’t hit the heart of the matter. If you want to make a difference, consume less."

Amar Mohanty, associate professor at the School of Packaging at Michigan State University, says that in a compost pile, paper bags will take just two to five months to biodegrade. But in terms of resource consumption, he says plastic bags are superior. "We are depleting the forests and we also use a large amount of water and energy to produce these paper bags," Mohanty says.

While some cities are pushing for outright plastic bans, in 2003 Ireland introduced the "Plastax," levying a fee of approximately 29 cents on each plastic bag a shopper uses. Cobb says he considers the tax to be widely successful, reducing Ireland’s annual 1.2-billion-bag habit by 90 percent. That’s one billion fewer bags. "The brilliance in the Plastax is that they tagged a cost on an item conceived as free," Cobb says.

Other alternatives to bans are also available. EPI distributes an environmentally benign chemical additive to packaging companies that Liu says can break down plastic bags completely from a few months to a few years. The bags break into pieces through a process called photodegradation. When the pieces are small enough, microorganisms can ingest and biodegrade them in a completely non-toxic process, Liu says.

"Banning plastic bags is not a very good solution because you don’t give people an alternative," Liu says. "Plastic gives us convenience, hygiene and other benefits, so I think we need a less-drastic solution."

Rayton Packaging President Patrick Arnell says his company annually makes 100 million additive-treated bags, some of which go to Costco, Wal-Mart and other supermarkets. The treated bags add a five to 10 percent price premium.

Mohanty argues, however, that chemical additives will only help a bag degrade if it is exposed to constant light and oxygen. Buried in a landfill, it may be unable to degrade.

Trellis Earth of Portland, Oregon makes corn-based plastics from polylactic acid (PLA) into bags that biodegrade in 120 days. "People are looking for a green alternative," says Trellis Earth cofounder Chad Biasi.

Though PLA could be used to make alternatives to petroleum-based polyethylene bags, Mohanty says the limited size of U.S. corn crops (already facing increased pressure from the ethanol industry) won’t be able to meet the demand.

The market for degradable and renewable resource-based plastics is continuing to grow. South American companies are making "green" polyethylene from sugar cane. This process reduces greenhouse gas emissions but the final product is not biodegradable. Other researchers are looking at wood waste, grasses, wheat straw and rice straw as possible source material for "green" plastic production.

The drawback to most of these processes is high cost. "The keystone of success in bio-based and biodegradable packaging depends on maintaining a balance among ecology, economy and technology," Mohanty says.

Cobb isn’t convinced. "Neither recycling nor biodegradable bags are the answer," he says. "We need to re-duce usage."

Reusable bags help achieve that goal. Some stores, including Whole Foods, now give a 5 to 10 cent credit for each reusable bag a shopper brings, and others (Ikea among them) have started charging customers the same amount for each plastic bag.