Bioplastics seem to have many benefits, but they aren't the perfect eco-friendly product we might hope for. For one thing, they're more expensive than petrochemical plastics, costing between 20 to 100 percent more [source: Dell].
As a result, bioplastics often end up in landfills where, deprived of oxygen, they may release methane, a greenhouse gas 23 times more potent than carbon dioxide. When bioplastics are not discarded properly, they can contaminate batches of recycled plastic and harm recycling infrastructure.