The U.S. Federal Railroad Administration said it was considering new regulations for the industry in the wake of a deadly July derailment in Lac-Megantic, Quebec. Railcars carrying so-called tar sands oil from North Dakota exploded in a derailment that left at least 40 people dead.
Lloyd Burton, a hazardous materials professor at the University of Colorado, told National Public Radio there were concerns about freight cars designated as Department of Transportation-111A, a cylindrical tanker.
"It's rigid, it's prone to derailment, and when it derails ... [it is] prone to puncture," he said in an interview broadcast Monday evening.
DOT-111A cars account for about 60 percent of the cars used in North America. The Association of American Railroads reports transportation of so-called tar sands by rail is on the rise because production gains place a burden on existing pipeline capacity.
Burton said DOT-111As aren't designed to handle what he said was the "most dangerous" form of crude oil. Tar sands are considered more corrosive than conventional grades.
NPR reports a U.S. federal review of the rail industry is on hold because of the partial federal government shutdown.
Notable deaths of 2014 [PHOTOS]