Rethinking the environmental impact of plant-based plastics

When I was at Wegmans the other day shopping for hair products, I found myself debating whether or not to purchase Pantene’s “Nature Fusion” shampoo, which comes in a plant-based bottle (“up to 59 percent excluding the cap”). Although it’s hard to imagine why someone would have to think twice about partaking in an eco-friendly action as simple as placing a bottle into a shopping cart, I was skeptical about how “green” the bottle actually was.

To assume that a bioplastic isn’t going to harm the earth just because it came from a plant is a little too naïve – there are many aspects of a product’s life cycle that must be taken into consideration when it comes to sustainability.

A study published in Environmental Science and Technology in 2010 found that the production of plant-based plastics is not necessarily more environmentally friendly than that of petroleum-derived plastics. This is due to the farming and subsequent chemical processing needed to transform a crop into a bottle. If the corn, soybeans or sugarcane utilized to produce biopolymers is not sustainably grown then the impacts of land use, fertilizer use and pesticide use serve to undermine the green intentions of the bioplastic products.

Fertilizers, pesticides and the intensive chemical processing of their production are large contributors to carcinogen emissions and ecotoxicity. While the “up to 59 percent” sugarcane-derived shampoo and conditioner bottles sold by Pantene reportedly consume over 70 percent less fossil fuel than conventional plastic, keep in mind that they are not completely carbon neutral because of the energy required for agriculture and processing.

The most compelling argument for the replacement of petroleum-derived plastic products with plant-derived plastics is the fact that bioplastics are biodegradable. It’s not, however, as simple as merely chucking the bottle in the trash and poof, it’s gone in a couple of days. Plant-based plastics need to be taken to an industrial composting facility for disposal and can’t be mixed with other plastics in your recycling. If you throw them in the trash they can take 100 to 1,000 years to decompose in a landfill. Still, that’s better than petroleum-derived plastic that will never decompose.

I’m not necessarily deeming bioplastics the spawn of the devil that should be exorcised from our supermarkets, but rather that consumers should be more critical when dealing with products advertised as eco-friendly. While plant-based plastics are far from ideal, I think there’s hope for them if they’re made from sustainably grown crops and processed using renewable energy. Future technological developments may have the potential to address some of the trade-offs associated with bioplastics and truly make them a low-impact substitute for petroleum.

For now, I think the best thing to do is to cut down on plastic consumption in the first place. I know this wouldn’t be easy but starting with something simple – such as going without bottled water or soft drinks – can go a long way.

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