Here's one for the "Nothing Is Simple" file... My obsession with plastic alternatives continues, fueled by the blog My Plastic-Free Life and the growing presence on the world's radar of what plastic debris is doing to our oceans (e.g., the Great Pacific Garbage Patch and its cousin in the Atlantic).
So my ears prick up every time I hear news about a plant-based alternative to standard petroleum-based plastics. For example:
In March of this year, Coca-Cola subsidiary Odwalla will reportedly start using 96%-100% plant-based bottles (from molasses and sugarcane) for all its single-serving beverages.
Case Western Reserve University professor David Schiraldi is working on a biodegradable substance that uses casein (from milk) and a spongelike material called aerogel.
And bioplastic maker Cereplast is branching out into algae-based plastics to supplement its resins made from corn, potatoes, tapioca, and wheat.
But check this out: A comparison of plant- and petroleum-derived plastics by researchers at the University of Pittsburgh suggests that bioplastics aren't necessarily better for the environment than their petroleum-based counterparts, according to Environmental Science & Technology.
Although biopolymers do well in terms of biodegradability, low toxicity, and use of renewable resources, they aren't so peachy on the production side, because the farming and refining required to make them tend to use lots of energy and put nasty chemicals into the environment.
A life-cycle assessment by the Pittsburgh team revealed that four common biopolymers are large contributors to ozone depletion. And two sugar-derived polymers — standard polylactic acid (PLA-G) and the type manufactured by Cargill subsidiary NatureWorks (PLA-NW), the most common sugar-based plastic in the United States — greatly contribute to eutrophication, the process by which water becomes unable to sustain life.
And here I was, all excited about the possibility of a future in which I might be able to buy things like yogurt, hummus, and lotion without wondering if the empty containers were destined to pollute the lungs of some Third World recycling worker or contribute to the ocean's chemical soup for hundreds of years. Still, I have to believe that these production problems are solvable. Especially since there's no hiding from the fact that, sooner or later, we're going to run out of oil.
Any LCA gurus out there care to weigh in?