US Pipeline & Hazardous Materials Safety Administration (PHMSA) said it would continue to study the differences between Bakken crude and oil produced in other areas.
The regulatory body warned that initial testing indicates that Bakken crude might have a lower flashpoint than expected and be more prone to catching fire if it spills from tank cars.
The caution came after a train carrying Bakken crude crashed and caught fire near Castleton, North Dakota — the latest in a series of high-profile accidents that have highlighted the growing trend of moving liquids production by rail.
