Dangerous gas should be removed from oil train shipments to prevent a future disaster on the tracks, U.S. mayors and safety officials will tell regulators in comments on a sweeping federal safety plan. The Department of Transportation in July proposed measures meant to end a string of fiery accidents as more trains carrying oil from North Dakota wind across the United States. Tank cars carrying flammable cargoes would be toughened and forced to move at slower speeds under the plan. But critics say the failure to address vapor pressure, a measure of how much volatile gas is contained in the crude, is a major omission, and intend to drive their point home. “That’s an oversight we’re going to push them to fix,” Elizabeth Harman, an official with the International Association of Fire Fighters, told Reuters. Responses to the DOT’s plan are due by Sept. 30, and so far more than 100 comments have been received. Typically in a contentious rulemaking major stakeholders submit their views just before the deadline. U.S. officials have studied vapor pressure since July 2013, when a runaway oil train derailed in the Quebec village of Lac- Megantic, killing 47 people in a fireball that shocked many with its explosive power. Until recently, official findings on vapor pressure were in line with industry-funded studies: That the North Dakota fuel is similar to other U.S. light crude oil deemed safe to move in standard tank cars. But the DOT said last week that it did not properly handle prior samples and that a precision device, a floating piston cylinder, is needed to reliably detect vapor pressure dangers. Given that disclaimer, many officials simply want dangerous gas removed from crude oil before it is loaded onto rail cars. “The technology exists so it boils down to costs,” said Mike Webb, a spokesman for Davis, California, who expects nearby cities will join a call for safer handling of Bakken crude from North Dakota. Under one scenario, energy companies would siphon gas from crude oil and send the fuel to market via different channels. But building such infrastructure, like separators or processing towers, could cost billions of dollars. The North Dakota Petroleum Council has sampled some Bakken fuel using a floating piston cylinder and the results have been inconclusive, said Kari Cutting, vice president for the trade group. “But nothing we’ve seen supports the idea that Bakken crude is more volatile than other light crude oils or other flammable liquids,” said Cutting. But leaders of many railside towns say uncertainty demands the fuel only move under the most stringent safety measures. “There is a way to haul dangerous cargo safely and that means using state-of-the-art tools,” said Karen Darch, mayor of the Chicago suburb of Barrington, where fuel-laden freight trains cross commuter tracks as many as 20 times a day. North Dakota officials will next week hold a hearing to consider measures to de-gasify crude oil in the state. (Reuters)