Crops Into Plastics

Less than 200 years ago, our economy was based on carbohydrates. Plants were the primary raw material in the production of dyes, chemicals, paints, inks, solvents, construction materials and even energy. Furthermore, cotton and wood pulp provided the world's first plastics.

By the mid-20th century, the carbohydrate economy had virtually disappeared, a victim of low crude oil prices and advances in manufacturing inexpensive plastics and other products from crude oil. Today, that economy is re-emerging. Three mutually reinforcing trends make a significant market for bioproducts (products made from plants) possible: technology; political factors, including the environmental movement and government regulations; and economic forces, primarily the rising prices of oil and natural gas.

Exactly what kind of impact bioplastics will have on the waste stream has yet to be determined. Meanwhile, the recycling outlook for conventional plastics is bleak. Plastics are the fastest growing part of the waste stream and among the most expensive discarded materials to manage. Plastics recycling levels have more or less leveled off and, for some products, even have decreased. In 2003, 25.2 percent of soda bottles were recycled, down from a high of 46.2 percent in 1995. According to the U.S. Environmental Protection Agency (EPA), only 8.9 percent of all plastic packaging was recycled in 2003.

By contrast, composting has dramatically increased in recent years. From 1990 to 2003, composting of yard trimmings rose from 12 percent to 56.3 percent, according to EPA. Aside from maintaining the productivity of soil and promoting sustainable agriculture, composting is a proven technology that can be successfully implemented at a local scale. This is good news for bioplastics, many of which can be composted in properly managed facilities. More than two dozen products have been certified as biodegradable by the U.S. Composting Council and the Biodegradable Products Institute.

Experts expect to see more composting facilities expand to accept food waste and compostable bioplastic products, particularly food service ware. In Europe, where bioplastics have gained greater market penetration, the trend is to compost these products along with other organics. In the Netherlands, approval at the ministerial level allows residents to add bioplastics to their green waste bins. Contamination of green waste has actually decreased as a result.

Despite the benefits of bioplastics over petro-plastics (plastics made from fossil fuels), many challenges lie ahead. For instance, will bioplastic bottles contaminate polyethylene terephthalate (PET) recycling programs? NatureWorks' corn starch-based polylactide (PLA) already is being made into a beverage container for Biota Spring Water. Should the bottles be labeled as compostable or recyclable? The company touts its PLA as both recyclable and compostable, citing independent technical studies that indicate PLA is not a recycling contaminate. Currently, PLA is not considered a contaminant because it has so little market share.

When bioplastics are fully rolled out, how will they ultimately affect recycling of conventional plastics? How will consumers know to recycle or compost products? These questions need to be addressed before the recycling community will embrace bioplastics, particularly beverage containers.

Bioplastics are positioned to become a permanent part of the marketplace. The next step is the implementation of needed commensurate policies to spur their success in the marketplace and to ensure they are properly recovered after their intended life.

Brenda Platt is the co-director of the Washington-based Institute for Local Self-Reliance (ILSR). She is currently coordinating ILSR's Sustainable Plastics Initiative.

Plastics Recycling vs. Composting

1990 2003
Discarded Plastics in Containers & Packaging
Generated (thousand tons) 6,900 11,910
Recycled (thousand tons) 260 1,060
Recycling Rate (%) 3.8% 8.9%
Discarded Yard Trimmings
Generated (thousand tons) 35,000 28,600
Composted (thousand tons) 4,200 16,100
Composting Rate (%) 12.0% 56.3%
Source: US EPA,