A study published in the American Chemical Society journal Environmental Science and Technology finds that plastics designed to degrade did not break down any faster than their conventional counterparts.

The researchers—Susan Selke, Rafael Auras and team —who were backed by the Center for Packaging Innovation and Sustainability at Michigan State University, evaluated plastics containing five different compounds designed to encourage breakdown. They reported finding no evidence that these additives enhanced biodegradability in compost or under simulated landfill conditions, or when buried in soil for three years.

The study concluded that anaerobic and aerobic biodegradation are not recommended as "feasible disposal routes for non-biodegradable plastics containing any of the five tested biodegradation-promoting additives."