@abcnews: "You can smell it." Students in school buildings and residents in neighboring homes were told to evacuate after a toxic chemical began leaking from a railcar Tuesday in Cleves, Ohio, near Cincinnati. Authorities said a pressure release valve was leaking styrene, a toxic and flammable chemical that is used to make plastic and rubber. It can cause headaches, nausea and respiratory issues, and long-term exposure can lead to more serious health problems including organ damage.