September 2009
Wither Plastic?
Plant-based bottles that decompose show promise for the
beleaguered bottled water industry
Imagine it: You down a bottle of water after a workout, toss the bottle away, and — poof — it disappears. That sci-fi fantasy is not as far-fetched as you might think. Although the bottled water industry has been widely criticized for the waste generated by all those plastic bottles, a few forward-thinking companies have introduced the ultimate eco-friendly packaging: recyclable bottles that can be broken down into just carbon dioxide and water after they're discarded.
The innovative bottles are made with polylactic acid (PLA), a resin produced through the fermentation of starch derived from corn or sugar cane. Unlike standard plastic, they are 100 percent petroleum free. Moreover, considerably less energy is used to produce the containers, compared with traditional plastic bottles.
Primo Water Corporation, based in Winston-Salem, N.C., is the first bottled water company to go national with plant-based bottles. Its water, drawn from local sources and filtered through reverse osmosis, is available in some 3,500 locations across the country, including supermarkets and college cafeterias. "From the start, we are not using oil and depleting nonrenewable resources," says Tim Ronan, vice president of marketing and communications at Primo. "It's innovative, sustainable, and, unlike oil, it can be used forever."
Some companies that use PLA bottles, such as Naturally Iowa, serve regional markets, while others are making inroads overseas. The question that remains, however, is whether these bottles have a long-term future in the beverage industry.
Benefits and Drawbacks
Much of the criticism of the bottled water industry points to the energy burned and the carbon released in the production of a plastic called polyethylene terephthalate (PET). The Container Recycling Institute reports that some 72 billion PET bottles were produced in the United States in 2006 (the most recent year for which it has an estimate), and more than half the PET bottles manufactured are used for bottled water. By some estimates, PET bottle production consumes 17 million barrels of oil annually — the equivalent of filling one-third of the bottles with oil.
In comparison, the bio-sourced PLA bottles, which are manufactured by Iowa-based NatureWorks, a subsidiary of agricultural giant Cargill, require 65 percent less energy to produce because less heat is needed to mold the resin. And the carbon released into the atmosphere is reduced by 68 percent. "When corn is grown, it's actually sequestering carbon from the atmosphere," Ronan explains, "as opposed to oil, which is pulled out of the ground and releases carbon into the environment."
Some environmentalists, however, claim the production of plant-based plastics leads to increased use of pesticides and fertilizers — to say nothing of genetically modified corn and other crops. Producing PLA bottles also costs more — about 5-10 percent more per bottle than the PET variety, although that translates to mere pennies at retail. (Primo absorbs that cost itself, selling its water for $0.99 to $1.19 at convenience stores, comparable to other brands.) Another major limitation of PLA bottles is that they break down when filled with carbonated beverages, such as soda or sparkling water.
That may be slowly changing, however. This June, San Francisco passed a law requiring businesses and residents in the city to compost food and other organic waste, beginning in October. The House of Representatives, meanwhile, recently switched to PLA bottles from Naturally Iowa for its cafeteria, creating visibility for the new material. Colleges and universities, too, are showing a burgeoning interest in composting food waste. Primo, in fact, has worked with several colleges to replace PET bottles with PLA ones.
Some companies aren't waiting for that infrastructure to develop, choosing instead to pursue other plant-based solutions. The Coca-Cola Company, for example, recently unveiled the PlantBottle, produced with a combination of petroleum and a plant resin derived from molasses. The bottle is indistinguishable from ordinary PET bottles. "The PlantBottle we have developed has all the chemical composition of PET, so it can be used across our entire product portfolio, not only with bottled water, but also with sparkling beverages," says Coca-Cola spokeswoman Lisa Manley. The PlantBottle, however, is not biodegradable, and 70 percent of the material is from non-renewable sources.
Hot-Button Issue
One roadblock to the wider use of plant-fiber bottles is a concern about mixing PLA and PET in the recycling stream. The plastics industry argues that adding just one plant-based bottle to a batch of 1,000 PET bottles will render the plastic unusable for recycling into new plastic bottles. "We take a stand that [PLA] shouldn't be included at all," says Dennis Sabourin, executive director of the National Association for PET Container Resources (NAPCOR), who cautions there is little data on whether PLA is safe to introduce to the ordinary recycling stream. "Is there a tolerable level? I can't answer that."
Meanwhile, the PLA industry says near-infrared sorting equipment already employed at most recycling centers can detect and sort PLA bottles with an accuracy of 96-99 percent. And a recent test conducted for Primo and NatureWorks by an independent consultant showed that mixing 35,000 pounds of PET bottles with 75 pounds of PLA bottles (a higher percentage than would be found in real-world conditions) did not contaminate the PET recycling process. "There was no clarity or haze difference in the test batch and the control batch," Ronan says. "What the test proved is, yes, the [PLA and PET] bottles can be sorted under high-volume conditions, and the product in the end was deemed to be indistinguishable."
If those results can be substantiated, it will give beverage companies the confidence to increase the use of plant-based bottles while they wait for more industrial composting facilities to come on line. That, in turn, will bring us all closer to the day when we can toss our water bottles with a clean — and green — conscience.
— Michael Blanding
http://magazine.continental.com/200909-iom