The Surface Transportation Board (STB) says it will consider a request by Union Pacific (UP) Railroad to clarify whether the carrier can avoid taking on lengthy new movements of chlorine, a toxic inhalation hazard chemical. Under federal law, rail carriers have a "common carrier" obligation to quote rates and provide service for all legitimate shippers. But the railroads have been trying to shift the financial risks of transporting highly hazardous chemicals onto shippers and perhaps eliminate some of those cargoes altogether. STB, which regulates the freight rail industry, says the proposed chlorine routes at issue—from Utah into Texas and Louisiana—would average 1,900 miles and travel through two "high threat urban areas" and several other large cities. "UP believes the risk of potential exposure from long-distance chlorine shipments is unnecessary, as all four destinations are located fewer than 300 miles from ample alternative chlorine supplies," STB says. In its petition, UP points out that federal security and safety agencies have asked the railroads to find ways to reduce shipments of highly hazardous materials to lessen the risk of a catastrophic release in the event of an accident or terrorist attack.