LANSING, Mich., March 18 (UPI) -- A new study suggests common additives in plastics advertised as biodegradable don't actually help products break down any faster than their non-biodegradable counterparts.

With human populations growing and landfills rising and expanding, plastic waste is a growing problem all over the world. Unlike many other types of waste, plastics take decades to break down. Some companies have claimed to solve this problem with so-called 'biodegradable' plastic. These plastics feature various additives that are said to bolster the products' chemical dissolution.


The plastics that don't end up crowding landfills often end up littering city streets, and accumulating in rivers, oceans and drinking water.

Recently, a team of Michigan State University researchers headed by Susan Selke and Rafael Auras tested the biodegradability of plastics featuring five different compounds said to promote chemical breakdown.

The research team, part of Michigan State's Center for Packaging Innovation and Sustainability, tested plastics under landfill conditions simulated in the lab, and also buried plastics in soil for three years. The results showed that none of compounds enhance biodegradability.

The study was published this week in the journal Environmental Science and Technology.

The results are similar to findings published in 2013 by researchers at Ohio State.

"I was skeptical about it from the beginning because those materials don't usually biodegrade," Fred Michel, a waste-management expert and professor at Ohio State University, told KQED last summer. "It's difficult to imagine a material you could add to them that would magically make them biodegradable."

Michel and and his colleagues also found the biodegradable claims of plastics manufacturers to be largely unreliable.

"I wasn't surprised," Michel said, "but it's just interesting that there are materials in the market like that, that have claims that don't seem to be justified in our testing."