NEW ORLEANS (AP) - The manufacturer of a chemical dispersant used to fight the 2010 BP oil spill in the Gulf of Mexico has asked a federal judge to dismiss claims over the government's use of its product. U.S. District Judge Carl Barbier didn't immediately rule Friday after hearing Illinois-based Nalco Co.'s argument that it isn't liable for how the federal government used Corexit to break up oil gushing from BP's blown-out well. A plaintiffs' attorney countered that Nalco is liable for claims it supplied a product that wasn't safe to use in the Gulf. More than 1.8 million gallons of dispersant were used in responding to the spill. A 2010 study by the Environmental Protection Agency found that Corexit, when mixed with oil, is no more toxic to aquatic life than oil alone.