Companies producing compostable plastics and bioplastics make big claims.
Green Dot Plastics declares, “We can lessen the environmental impact of products we love and use every day.” According to Grand View Research, the global bioplastics market will grow at a compound annual growth rate of 18.8 percent from 2023 to 2030.
A survey of consumers in 42 countries found “positive expectations” of bioplastics. But how sustainable are compostable plastics and bioplastics?
Bioplastics: The Waste Problem
Both bioplastics and compostable plastics create waste problems. Most plastics labeled compostable can only be composted in an industrial facility. A 2018 US survey found that only half of the facilities surveyed could accept compostable plastic waste. A consumer who puts bioplastics in the recycling bin is likely unaware that it is not recyclable. Instead of being recycled, bioplastics add to the growing stream of plastic waste. “Introducing biodegradable plastics into the system will make recycling more challenging,” according to a Greenpeace report.
Bioplastics that end up in landfills release methane, just as their conventional cousins do. Methane is a greenhouse gas with a warming potential of 80 times that of carbon dioxide. Since bioplastics can’t be recycled, landfills are where they will likely end up. Methane accounts for around 30 percent of the rise in global temperature.
The Labels Problem
Labels on bioplastics and conventional plastics are ambiguous. A joint report by the UN Environment Program and Consumers International found “considerable room for improvement” on the labels and claims regarding the recyclability of conventional plastic packaging. Similar confusion exists with bioplastics.
British researchers asked 1,648 people to test the environmental performance of compostable plastics. They found that the public needs clarification about the labels of compostable and biodegradable plastics. Only 14 percent of the sample plastic packaging tested was certified as “industrial compostable” only, and 46 percent had no certification. Most of the compostable and biodegradable plastics tested did not fully disintegrate, including the 60 percent certified as “home compostable.” They concluded that “home composting is not an effective or environmentally beneficial waste processing method for biodegradable or compostable packaging.”
A report by Closed Loop Partners’ Composting Consortium and the Biodegradable Products Institute (BPI) found that Americans are just as confused. Up to 49 percent of those surveyed had trouble differentiating between “compostable” and “biodegradable.” Up to 50 percent said they would put packaging labeled “made from plants” in the composting bin. One-third said they would put commercially compostable items in their compost bins.
Two California laws prohibit the use of the labels biodegradable and compostable. The 2012 SB 567 law prohibits the labeling of plastic products as biodegradable. Ten years later, AB 1201 prohibits labeling plastic products as compostable or home compostable unless the products meet certain criteria. An EU law prohibits the use of the label biodegradable without proof.
The Greenwashing Problem
There is still another problem with compostable plastic and bioplastics. Some plastic labeled as bioplastic contains fossil fuel-based conventional plastic. Researchers tested bioplastics and found that half of the plastic products labeled bioplastic contained traditional plastic. The term bioplastics includes products that contain up to 75 percent fossil fuels. And some compostable plastics are made from fossil fuels. Extracting fossil fuels and transforming them into plastics emits 1.5 to 12.5 million metric tons of greenhouse gases. Refining plastics emits 184 to 213 metric tons of greenhouse gases annually.
The Natural Resources Defense Council defines greenwashing as “the act of making false or misleading statements about the environmental benefits of a product or practice.”
If bioplastics and compostable plastics contain fossil fuels, environmental claims become nullified. A case of serious greenwashing can be made for the hype surrounding both types of plastic.
