Emma Lankford, Guest Writer
Plant–based plastics appeal to environmentally conscious consumers because they are made of renewable resources. However, a study done by Michealangelo Tabone suggests that these biopolymers are less green than they are thought to be.
Since 1950, the world has produced over nine billion tons of plastic, according to phys.org. At this rate, twenty–three percent of the plastic produced has made its way and will continue to travel into the ocean, harming wildlife and destroying fragile ecosystems. The National Geographic reported that at least seven hundred species of marine animals have been affected by polymer waste. Conventional plastics, made from petroleum products, can take up to five hundred years to fully degrade. Biopolymers, on the other hand, take roughly a year to five years to fully degrade, making them a seemingly ideal replacement.
“The main concern for us is that these plant-derived products have a green stamp on them just because they’re derived from biomass,” says Amy Landis, a member of Tabone’s study. “It’s not true that they should be considered sustainable. Just because they’re plants doesn’t mean they’re green.”
According to The World Congress on Biopolymers, biopolymers are chain–like molecules made up of repeating structures. Biopolymers are created from either starch from plants such as cornhusks, or from bacteria cultures developed by fermentation. Conventional plastics are created from refining petroleum. Biopolymers degrade faster than conventional plastics because they use living organisms as a base material.
However, while there is not a negative environmental impact from decomposition, biopolymers do exhibit negative side effects from their production. Research determines that the pesticides and fertilizers used to grow biopolymer starting materials have a negative effect on the environment. Although biopolymers reduce the amount of nonrenewable resources used, such as fossil fuels, the impacts on eutrophication, human health, and eco-toxicity are increased.
Research suggests that some biopolymers need assistance from high temperatures or light to become readily biodegradable. Few facilities are equipped with machines that will get hot enough to initiate degradation. When they do degrade, biopolymers emit methane, carbon dioxide, and water—the same as petroleum polymers do, but in smaller amounts. However, the impact on global warming is less than compared to petroleum plastics.
“I don’t want people to take away from this that biopolymers are bad,” says Landis. “There is a lot of research going on to create biopolymers based on non-corn feed stocks.”
This research suggests that biopolymers are more efficient than petroleum polymers, especially for non–recyclable materials, such as single use products. The main problem applies to the production of bioplastics, which could be resolved by creating a non–corn feedstock as Landis suggested. The consumers can also make a difference by purchasing non-polymer products, or recycling and reusing polymer products after use.
Biopolymers have also become increasingly controversial because they require plants that could be used for food. Green-orientated companies, such as the Full Cycle Bioplastics in California, have tried to reduce this impact that biopolymers have on food resources and agricultural land. Instead of using edible food products, these companies create biopolymers from food waste, crop residue (such as inedible leaves), garden waste, woody biomass, algae, and un-recycled paper or cardboard. This style of production also reduces the amount of toxic chemicals used in the fertilizers and provides another use for unwanted food.
Consumers have the power in their wallets. On one hand, biopolymers are hazardous to make and can be considered a health concern to the public. On the other, the degradation of biopolymers has fewer effects on the environment and health than petroleum products. The difference between conventional polymers and biopolymers is time. While there has been more time to fix and troubleshoot the production of conventional polymers, biopolymers are new and just now being explored. As time continues, innovation in biopolymers continues as well. Greener plastics may be on the horizon.