Styrofoam cups are among the items banned under Maine's new law.

(Spencer Platt/Getty Images)

At a Glance

The law goes into effect Jan. 1.Other states are considering a similar ban. Americans throw away an estimated 25 billion styrofoam cups each year.

Maine became the first U.S. state to ban plastic foam containers, commonly referred to as Styrofoam, with a bill signed into law Tuesday.

The new law prohibits businesses such as convenience stores, grocery stores and restaurants from selling or distributing plastic foam containers, which are made out of a substance called polystyrene. The list of banned items includes cups, take-out containers, plates and bowls.

“Polystyrene cannot be like a lot of other products, so while that cup of coffee may be finished, the Styrofoam cup it was in is not,” Maine Gov. Janet Mills said, according to a report in the Boston Herald. “In fact, it will be around for decades to come and eventually it will break down into particles, polluting our environment, hurting our wildlife and even detrimentally impacting our economy.”

Maryland passed a earlier this month but it hasn't been signed into law yet. Colorado, Oregon and New Jersey are among other states considering .

Dozens of across the U.S. have also banned single-use plastic foam containers, including New York City, Washington, D.C., Chicago and Boston.

A 2016 study by researchers at Saint Louis University estimated that polystyrene takes up as much as of the landfill capacity in the U.S. and that Americans throw away some 25 billion plastic foam cups each year.

Like all plastics, polystyrene doesn't decompose - it lasts forever. It's also lightweight and easily carried by wind or water into the ocean, and crumbles into small pieces that can linger in soils and waterways for centuries, environmentalists say.

"People think it , because you see it breaking in smaller and smaller pieces, but in some ways those are more harmful because they can more easily be consumed by animals and even humans," Jacqueline Savitz, chief policy officer of North America at Oceana, an ocean conservancy nonprofit, told CBS News.

The Environmental Protection Agency considers polystyrene a that may cause cancer and other health issues.

Polystyrene can be recycled, but only if it's very clean and if facilities are available to do so.

"Imagine if you took all the different types of polystyrene packaging out there - plates, cups, meat trays," Martin Bourque, executive director of the Ecology Center in Berkeley, California, told CBS News. "It's going to have food stains on it, it's going to be all different colors, and it's going to be all this foam you have to densify. You're not going to get food-grade polystyrene out of that, no way. You've just got this very low-grade goop that you can use for some very limited, very low-grade applications."