No More Plastics Part III

My neighbour looked at my cloth shopping bags and said, "Why bother? The bags at [insert grocery store name here] are corn-based and bio-degradable."

But the trouble is, that like a lot of quick environmental fixes which simply enable us to continue to consume, corn-based plastics are not a quick fix.


NatureWorks LLC, a subsidiary of Cargill Dow, operates a factory in Nebraska which generates more than 300 million pounds of corn-based polymer plastic per year — using 40,000 bushels of Cargill corn every day in the process. This corn-derived polymer is sold to manufacturers of soft-drink cups, bag makers, salad and fruit containers, as well as a lot of other products. But is corn-based polymer really an environmentally friendly alternative?

Corn-based plastics are 100 percent biodegradable — in a controlled environment. They require at least a consistent temperature of 60 C (140 degree F) at 90% humidity for 40 to 60 days to decompose. Given those conditions, they degrade into carbon, hydrogen and oxygen. However, in your average city landfill or compost pile corn-based polymer does not degrade more quickly than other plastics.

And as for getting away from oil, the genetically engineered corn used to manufacture corn-based polymer is the most petroleum intensive crop grown, after cotton. GE corn threatens non GE food crops through pollen drift and cross pollination and it is engineered to kill the larvae of many pollinators, including the Monarch butterfly and other beneficial insects. It fails to kill the African Cotton Worm, but kills the green Lacewing that eats Cotton Worms.

And there seems to be something perverse, to me anyway, of growing huge amounts of corn for fuel and polymer in a time when families are struggling to buy food, the cost of which is artificially raised by diverting land used for food crops into producing plastics and fuel. Why not promote conservation and sustainability instead? But then I am becoming an old crank I suppose. Can't see why we have to have disposable everything. Soon we will be the disposables if we don't stop this madness.