Composting that Plastic

Finally materials scientists and designers have picked up on cellophane’s greatest ecological asset: biodegradability. And they are running with it. The cellulose-based packaging material now has many plant-based cousins, each able to disappear into a compost heap within 180 days, the requirement of the < href=””>Biodegradable Products Institute’s “Specifications for Compostable Plastics.” These new corn and potato-based plastics can work in congruence with municipal waste streams of the future that capture food waste and send it to compost sites in every city and town.

American, European, and Japanese companies have put a host of bioplastic products on the market. These include extrusion coating for paper, styrofoam, waste bags, and envelope windows to disposable cutlery, cups, straws lids, plates, and take-out containers in the food sector; and with them the plastics industry may be turned upside down by biodegradable resins. Traditional plastics made with petroleum-based resins not only require fossil fuels for production but also can take hundreds of years to biodegrade in landfills. While bioplastics do not biodegrade easily in landfills without water and can produce methane, a greenhouse gas, they are designed to decompose fully in compost heaps with sufficient heat and moisture.

In 2002, Biocorp North America, one of the leading producers of biodegradable packaging, took its biggest step in introducing Americans to the revolutionary concept of plastic that can disintegrate alongside food waste. At the Salt Lake City Olympics, Biocorp partnered with the Coca-Cola Company to provide 100 percent biodegradable cups—paper cups coated with biodegradable film and clear plastic cups made with Natureworks PLA, a biodegradable plastic resin manufactured by Cargill Dow. Biocorp also supplied compostable bags for the cups and special bins to ensure that the cups would be isolated from the non-biodegradable waste. Salt Lake City was responsible for picking up and composting the cups at a local composting site.

Despite mainstream applications like the Olympics, zero-waste advocates and designers alike face significant challenges in integrating bioplastics into the cultural and economic mainstream. While there are more than 4,000 compost sites in the United States, few are devoted to food waste. To change this trend, local governments will need to make proactive commitments and devote considerable resources to divert organic waste from landfills into compost sites. Consumer education on the benefits of recycling organic waste and composting at home is also critical to nurturing a culture of everyday composting.

On the design side, bioplastics have processing characteristics different from traditional plastics. If biodegradable resins are to replace petroleum-based resins, they will need to be able to smoothly adapt to traditional plastic processing plants. As Steve Mojo, executive director of the Biodegradable Products Institute says, “We are at the beginning stages of the development and adoption curve of this recent innovation of biodegradable plastic. I expect to see significant growth in the coming months and years.”

Biodegradable resins are also expensive. According to Frederic Scheer, CEO of Biocorp, one of the most significant boosts to the industry has been Cargill Dow’s recent investment of $1 billion in a large production plant to further develop and produce their corn-based resin, Natureworks PLA. Slowly, resins are becoming more affordable and therefore more accessible to new designers and producers.

A future of take-out garbage and trash bags that go in the compost heap with food scraps to be reborn as rich soil is certainly alluring. “Recycling is now a reality compared to fifty years ago,” says Scheer. “The next step will be composting and waste reduction.”

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