Microwaving some kinds of containers, including cups, can accelerate the chemical leaching process, which triggers the movement of chemicals out of plastic containers and into food, says Fulton Schools Professor Rolf Halden, director of ASU’s Biodesign Center for Environmental Health Engineering. The U.S. Department of Health and Human Services backs him up on that warning, especially when containers are made from expanded polystyrene foams — plastics made from tiny beads that are heated and molded into a specific shape. Styrene, a chemical in those foams, is considered a “reasonably anticipated human carcinogen.” Halden recommends heating food or drinks in a microwave-safe container made of glass. The U.S. Food and Drug Administration also suggests microwave-safe plastic and ceramic as suitable choices for microwaving.