In a world that can seem overwhelmed by potentially eternal plastic waste, are biodegradables the ultimate solution? Probably not. But it’s complicated. The industry is still debating what “biodegradable” actually means. And some plastics made of fossil fuels will biodegrade, while some plant-based “bioplastics” won’t.
Biodegradable plastics have been around since the late 1980s. They initially were marketed with the implied promise that they’d somehow disappear once they were disposed of, just as leaves on the forest floor are decomposed by fungi and soil microbes. It hasn’t quite worked out that way.
Biodegradables don’t live up to their promise, for example, in the dark, oxygen-free environment of a commercial landfill or in the cool waters of the ocean, if they should end up there. You can’t throw them in your backyard compost either. To break down, they require the 130-degree heat of an industrial composter. Many industrial composters accept only plastics that meet certain standards, ensuring they will leave no fragments behind that can harm the environment or human health. And if you throw some biodegradables in with recyclables, you might ruin the latter, creating a mix that can no longer be relied on to make durable new plastic.