Mercury, a silver-colored liquid metal, is extremely toxic to the nervous system and may impair the way we see, hear, walk and talk. When spilled, mercury can evaporate at room temperature and the vapors cannot be seen, smelled or tasted. In the environment, mercury can be converted into a form that is especially toxic and can build up in fish tissue. Because of its potential to pose long-lasting health and environmental risks, mercury has become a high-profile toxic waste. Some cars may contain no mercury components, while others may contain several. Mercury is not something you would want to be caught mishandling.