Numerous replacements have been proposed for plastic amid growing concerns over the amount of waste plastics that end up in the environment and increasing prevalence of single-use plastic bans.
Biodegradable carrier bags are one proposed solution, although they can take up to 3 years to break down. “What worries me is that this isn’t really a solution, it’s just swapping one polymer for another,” Mark Miodownik, professor of materials and society at University College London, tells the paper. ”If they end up in the environment, then it really does depend on the conditions that they find themselves in as to whether they biodegrade in any reasonable time.”
Many products that are advertised as compostable only break down in industrial machines, for example. Biodegradable plastics on the other hand usually aren’t composted but can take an extended amount of time to be broken down by microorganisms in the environment.
“For millions of people in their everyday lives, the best thing is to have plastics that don’t biodegrade, that have long lives – that’s the whole brilliant point of them – and that get collected and recycled back into new things,” says Miodownik.