Can Bioplastics Save Us?


Appeared in:

  • Orange Coast Voice, February 2007, page 5.
  • Sierra Club – Mt. Baldy Group, Angeles Chapter newsletter, Jan-Feb 2007, page 4
  • Sierra Club – San Fernando Valley chapter newsletter March 2006.

Can Bioplastics Save Us?
(#7 of the Plastic Plague series)
Sarah S. Mosko, Ph.D.

Most bioplastics on the market require industry composting, so the products just end up in the landfill.

Most bioplastics on the market require industry composting, so the products just end up in the landfill.

Bioplastics. They gotta be better than petroleum plastics, right? A short list of problems linked to petroleum plastics includes oil spills, release of toxins during synthesis, exposure to endocrine disrupting chemicals during routine use, threats to wildlife from ingestion or entanglement, environmental pollution during disposal, and maybe even a basis for wars as global petroleum supplies dwindle. Furthermore, petroleum plastics do not biodegrade, creating a ballooning litter problem on land and sea as global plastics production has risen to about 250 billion pounds annually.

But will conversion to a plant-based substitute really solve everything? Considering a few key questions should help us ferret out some of the critical issues that would need to be addressed before we can give bioplastics a thumbs up or down.

Is bioplastic technology ready?
Even though you won’t find them on major supermarket shelves, some forward-looking companies have figured out how to make disposable plastic items (such as cups, bowls, plates, clamshells,cutlery, bottles, food trays, produce bags and packing peanuts) from soy, corn, sugar cane or grass. For example, a well-known multinational corporation is marketing a corn-based resin that can be melted, spun or molded into various products. The corn is broken down enzymatically into dextrose that is fermented (by microbes) into lactic acid that, in turn, is transformed into a polymer resin. Called polylactic acid or PLA, the resin is touted to be “plasticizer-free” (some petroleum plastics also contain endocrine disrupting chemicals as softeners) and completely broken down within months in an industrial composter. This sounds good on the surface, but the relatively rapid decomposition rate might limit applications to products with short shelf or usage lives. On the other hand, breakdown might occur extremely slowly or not at all in a backyard compost or along the roadside as litter because both temperature and humidity must be tightly controlled for degradation to occur. Furthermore, ongoing studies at the Algalita Marine Research Foundation in Redondo Beach, CA are showing little, if any, breakdown of a plastic clamshell made from corn in the marine environment where the accumulation of plastic debris has reached critical levels in some areas.

What would be the consequences of large-scale conversion to bioplastics?
The short answer is no one really knows as this is uncharted territory. However, you do not have to ponder too long to come up with a number of reasonable concerns. For starters, mull over what greatly intensified farming of, say, corn or soy, for making bioplastics would mean in terms of:

  • Competition for farmland for growing human or animal feed crops.
  • Demand for fossil fuels needed to manufacture and run farm machinery.
  • Greenhouse gas emissions stemming from energy used throughout the production process.
  • Aquifer depletion for irrigation.
  • Environmental pollution from increased application of pesticides, herbicides and fertilizers.
  • Likely reliance on genetically modified feed stocks by large-scale corporate farmers.
  • Erosion of soil and nutrient leaching.
  • Wildlife habitat destruction.
  • Disruption of rural communities.
  • Fate of the sludge and contaminated water produced as byproducts during manufacture of bioplastics.
  • Assurance that dangerous chemicals would not be added later to the virgin resin during fabrication of final marketed products.
  • Our solid waste stream that is ill-prepared to handle a large influx of bioplastics dependent on industrial commposting.

What can we conclude?
For now, the good news about bioplastics might boil down to their derivation from renewable energy sources, ability to biodegrade in a highly controlled composting environment, and perhaps absence of some toxic chemical additives like plasticizers. But it would be terribly naïve to think that simply switching to bioplastics will solve everything. Rarely is anything so simple. Our society’s mindless over-consumption of plastics, especially single-use disposables such as plastic bags and drink bottles, has everything to do with the problems that stem from petroleum plastics. So does the manufacturing juggernaut to make everything possible out of plastic. Just because something can be made from plastic does not mean it is the best material. Case in point: more than 30,000 tons of plastic waste could be eliminated yearly if Americans all used cloth bags for grocery carryout. (Millions of trees would be spared as well.) So even though we should applaud the innovation behind bioplastic alternatives, we must also be willing to take a long, hard look in the mirror and accept personal responsibility for our consumer behavior. It is crucial that we commit to making a U-turn away from our current “throwaway” mindset back toward the “use it up, make it due or go without” mindset on which our parents and grandparents were raised. Otherwise, we might find that we’ve only substituted one set of troubling plastic problems for another.

To participate in a California-based statewide plastics reduction campaign, contact Earth Resource Foundation or call (949) 645-5163.

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