Bio-plastics ‘aren’t necessarily greener than oil-based relatives’

WASHINGTON - Biopolymers are more eco-friendly, but farming and energy-intense chemical processing means they are dirtier to produce than petroleum-derived plastics, according to a new study.

University of Pittsburgh researchers suggest that biopolymers are not necessarily better for the environment than their petroleum-based relatives and that traditional plastics can be less environmentally taxing to produce.

Michaelangelo Tabone conducted the analysis as an undergraduate student in the lab of Amy Landis, a professor of civil and environmental engineering in Pitt’s Swanson School of Engineering.

The researchers examined 12 plastics in their finished form against principles of green design, including biodegradability, energy efficiency, wastefulness, and toxicity.

The team attributed the pollution caused by biopolymers to agricultural fertilizers and pesticides, extensive land use for farming, and the intense chemical processing needed to convert plants into plastic.

They also found that some biopolymers were the largest contributors to ozone depletion. One type of the corn-based polyhydroyalkanoate, PHA-G, topped the acidification category. In addition, biopolymers exceeded most of the petroleum-based polymers for ecotoxicity and carcinogen emissions.

Once in use, however, biopolymers bested traditional polymers for ecofriendliness.

On the other hand, the ubiquitous plastic polypropylene (PP)-widely used in packaging-was the cleanest polymer to produce, but didn’t pass the test for sustainable material.

Landis is continuing the project by subjecting the polymers to a full LCA, which will also examine the materials’ environmental impact throughout their use and eventual disposal.

The report is published in Environmental Science and Technology. (ANI)