Food grade Styrofoam (polystyrene) and other Styrofoam to-go containers and cups should be thrown in the trash. They cannot be recycled locally and are not biodegradable. 

When possible, avoid using Styrofoam containers altogether and opt for reusable containers! Consider bringing reusable containers (such as Tupperware) to restaurants for leftovers and a reusable mug for coffee on the go.