Hazardous materials are essential to the economy of the U.S. and the well being of its people. They fuel our cars and trucks and heat and cool our homes and offices. Hazardous materials are used in farming and medical applications and in manufacturing, mining, and other industrial processes. Millions of tons of explosive, poisonous, corrosive, flammable, and radioactive materials are transported every day. Hazardous materials move by plane, train, truck, or vessel in quantities ranging from several ounces to many thousands of gallons. In the wrong hands, however, hazardous materials can pose a significant threat. Addressing this threat is vital to protecting our citizens and our economy.