"Paper, Plastic or "Bioplastic?"

From the Christian Science Monitor - by way of CBSnews.com - by Tony Azios

Paper, plastic ... or biodegradable? Yes, get ready to add a third option at the grocery store checkout line as biodegradable plastics enter the mainstream consumer market.

It is hard to imagine that the plastic grocery bag made its debut only 30 years ago. But now, even in Antarctica, scientists regularly find them blowing about.

The problem is that, unlike many other overnight sensations, plastics stick around. It can take roughly 1,000 years for some petroleum-based plastics to disintegrate. And when they do disintegrate, traditional plastics leave behind a messy legacy of fragments and chemical residues that get absorbed into streams and soil. In the meantime, they clog landfills and rivers, or kill whales and sea turtles that mistake them for food. With up to 1 trillion plastic bags manufactured annually and 2.7 million tons of plastic used just to bottle water each year, concern is rising worldwide.

Enter bioplastics, designed to degrade into an ecofriendly mix of water, carbon dioxide, and biomass. While biodegradable plastics have been introduced before in the past 20 years, they have failed to achieve widespread use due to their inferior strength and higher cost. But this is changing, says Steve Mojo, executive director of the Biodegradable Products Institute (BPI) in New York City....

Currently, both companies' products are primarily made of modified corn feedstock, as opposed to petroleum byproducts. Ultimately, the natural polymers biodegrade as microorganisms consume them. While this source of plastic seems earth friendly, some environmentalists say the footprint of corn cultivation should be considered.

"Corn, overall, is very energy intensive, requiring a considerable amount of fertilizer and gasoline to produce and transport each bushel," says Janet Larsen, research director of the Earth Policy Institute in Washington. "The nitrogen-rich fertilizer then often becomes runoff in streams, rivers, and oceans, creating algal blooms that kill marine life."

Using feedstock for plastic further exacerbates record high corn prices, says Ms. Larsen, adding that corn supplies are already stretched thin by demands for food and ethanol. "This should make society ask, 'Do we really want to be turning food into plastic?'"

..."There is a widespread confusion that all [bioplastics] are made from renewable resources and that all of them are biodegradable," says BPI's Mojo. "Not all plastics made from renewable resources are biodegradable, and not all that are biodegradable are based on natural resources."

Mojo, who works closely with the American Society for Testing and Materials International to develop specifications for products that biodegrade in various environments, says that "the industry is in its infancy" and work is being done to develop more uniformity in composting and recyclability. "We will see more bioplastics in the next five to 10 years as technology advances, and we will see visible improvements in strength, cost, and degradability," he adds.

In the meantime, Larsen of the Earth Policy Institute suggests the environmentally conscious choose a fourth option at the checkout line: "We would do better to bring our own canvas bags shopping or buy reusable water bottles and move away from the throwaway mentality that one-time use products afford us."