A major component of ocean pollution is less devastating and more manageable than usually portrayed, according to a scientific team at the Woods Hole Oceanographic Institution on Cape Cod, Mass., and the Massachusetts Institute of Technology.

Previous studies, including one last year by the United Nations Environment Program, have estimated that polystyrene, a ubiquitous plastic found in trash , could take thousands of years to degrade, making it nearly eternal. But in a new paper, five scientists found that sunlight can degrade polystyrene in centuries or even decades.

“Policymakers generally assume that polystyrene lasts forever,” Collin P. Ward, a marine chemist at Woods Hole and the study’s lead author said in a statement on Thursday. “That’s part of the justification for writing policy that bans it.” A main rationale for his team’s study, he added, “was to understand if polystyrene actually does last forever.”

Polystyrene, one form of which often carries the brand name Styrofoam, is used to manufacture single-use cups, straws, yogurt containers, disposable razors, plastic tableware, packing materials and many other everyday items, which are discarded daily by the ton . Much of it ends up in the ocean. A swirling mass of throwaway junk known as the Great Pacific Garbage Patch, located between Hawaii and California, is estimated to occupy an area roughly twice the size of Texas.