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It’s no longer a secret that single-use plastic is harming the planet. Not only does the process of creating these materials emit enormous amounts of planet-warming gases, but they also can take centuries to decompose in a landfill.
So as demand for climate action escalates and the dangers of plastics become more evident, consumers are turning to so-called compostable and biodegradable alternatives for things like food containers, cups, plates, cutlery and bags, in hopes of mitigating further climate and environmental harms.
But unfortunately, researchers say those products are also a problem.
A new study conducted in the UK found that 60% of products labeled as compostable do not fully break down in home compost. And unlike conventional plastics, these alternatives are largely unregulated, despite their advertised benefits.
“In the lab, where [these plastics] have been tested and have been paid for by a manufacturer, they behaved in one way and they’ve been determined to be compostable in a home composter,” Danielle Purkiss, researcher and lead author of the study, told CNN. “But what’s happened is we’ve seen a lot of these pieces of packaging with certification still don’t break down in these different home composting conditions.”
The study shows “there’s a problem with the lab testing versus the real-world conditions where these materials are being disposed,” Purkiss told CNN.
The real impact of ‘compostable’ plastic
Although compostable and biodegradable packaging and flatware are touted as being environmentally friendly, they are still resource- and energy-intensive to produce, according to Judith Enck, a former Environmental Protection Agency regional administrator and now president of Beyond Plastics, a non-profit focused on research and consumer education.
In addition to the greenhouse gases released from industrial facilities making these products, the crops used as feedstock, such as corn or sugar beets, also require significant amounts of fossil fuels, farmland and water to create them — all resources that could instead go to actual food, Enck said.
Though compostables are still slightly better than conventional plastics, Enck told CNN, “people shouldn’t fool themselves into thinking that it actually gets composted.”
“There’s a bit of greenwashing going on here,” she added.
Researchers say the messaging has not been clear around how sustainable these compostable options are. One of the key findings of the report, Purkiss said, is that people are confused and don’t know the meaning of the labels on compostable and biodegradable plastic items.
The bottom line is that companies still use some fossil fuels in these products, yet continue to market them as sustainable, which leads to improper disposal of plastic waste. Biodegradable plastic for instance, while bio-based, can still be made at least in part with fossil fuels.
Ultimately, compostable products are designed to fully decompose only at industrial compost facilities that regulate the temperature to achieve peak composting efficiency. But most of these products don’t wind up there, Enck and Purkiss said – they end up at regular landfills, where they will persist for years, just like conventional plastics. Or they will be burned in trash incinerators, where they release methane, a potent greenhouse gas.
“It pains me to say this because I want non-plastic alternatives to work,” Enck said, “but there really is no such thing as biodegradable plastics, and compostable packaging really only gets composted at high-temperature composting facilities.”
What you can do instead
Experts who spoke to CNN said the fact that people are already willing to move away from single-use plastics into more sustainable options is a great first step. And there are other ways you can reduce your impact.
Purkiss and fellow researchers at the University College London designed a citizen-science study in which more than 1,600 participants in the UK so far have voluntarily experimented with home composting. Purkiss said other people can also take part in the “Big Compost Experiment” to help scientists learn more about the impact of these products.
Purkiss also said it’s important for consumers to vote with their wallets.
“A citizen has lots of ways they can affect change, and one way they can really influence behavior is through their buying decisions,” Purkiss said. “They need to put pressure on manufacturers and business to move towards more properly sustainable models.”
Here are some more ways to reduce the amount of plastic in your everyday life:
Skip biodegradable plastic — It’s a misnomer, Enck said. Instead, use reusable or refillable items when you can, or opt for packaging that’s made from recycled material and can easily be recycled.
Have reusables and refillables ready — Bring reusable bags when you go to the grocery store, not just for all your items but also for your favorite produce. Use refillable mugs or thermos cups for your coffee or tea while on the go, and same goes for a refillable water bottle.
Choose paper (or no) packaging over plastic — If you’re looking at two versions of the same product and one is packaged in paper or cardboard and the other is in plastic, then the choice is obvious. For food or take-outs at restaurants, opt for aluminum packaging that can be recycled instead.
Bring your own cutlery or to-go containers — Enck takes her own utensils and reusable containers to restaurants that usually serve food in single-use plastic. Not all restaurants will allow this, she said, but it’s important to support the ones that do.