Maine has become the first state in the nation to ban Styrofoam containers.

Gov. Janet Mills signed into law last week a bill that would require companies to stop giving out cups and other single-use containers made of polystyrene foam, commonly known as Styrofoam, by January 2021.

Joining Boston Public Radio to weigh in was Corby Kummer, a senior editor at The Atlantic, an award-winning food writer, and a senior lecturer at the Tufts Friedman School of Nutrition and Policy.

Kummer explained that polystyrene products cannot be recycled in most statesand instead end up in landfills, where they don't biodegrade.

"In a million years, [the containers] don't degrade. Nothing happens to them. They just stay the way they are. This is why Styrofoam — or really polystyrene, [because] Styrofoam is a trade name, like Kleenex — doesn't degrade, it is the worst possible cause of plastics pollution," Kummer said.

Kummer praised the leadership of Mills, who began her term earlier this year, on this issue.

"This is such a sign that in the absence of federal leadership, it's locals who get things done," Kummer said.