WASHINGTON -- The agency that oversees pipeline and hazardous material safety in the United States issued a warning late Thursday that oil extracted from shale rock formations in parts of North America may be more flammable than conventional oil.
The alert comes after a train carrying crude derailed in southeastern North Dakota earlier this week and burst into flames. Safety officials are still investigating what caused 18 of the 106 cars on the oil train to come off the tracks. The accident follows several other recent incidents involving trains carrying crude oil that burst into flames, including one in Quebec last July that killed 50 people.
The Department of Transportation's Pipeline and Hazardous Materials Safety Administration posted the alert for the public, emergency responders and companies that carry crude. The statement notes that "the type of crude oil being transported from the Bakken region may be more flammable than traditional heavy crude oil." The Bakken shale lies under parts of North Dakota and Montana, and the Canadian provinces of Saskatchewan and Manitoba.
A train carrying crude oil derailed in Alabama last November also resulting in a fire. The agency said that, based on the recent fires, it is "reinforcing the requirement to properly test, characterize, classify, and where appropriate sufficiently degasify hazardous materials prior to and during transportation." The pipeline safety agency and the Federal Railroad Administration had issued a previous safety advisory last November.
The two agencies said they have stepped up their investigative efforts, including making unannounced inspections and testing crude oil samples on rail to verify that shippers are properly classifying and packaging materials for shipment. Shippers are required to use greater care in transporting certain chemicals.
The issue of exploding trains has prompted more deliberations over the transportation of crude oil. While environmental groups have protested plans to build the Keystone XL and other oil pipelines to transport crude from the Canadian tar sands, proponents of the development have argued that pipelines are a safer alternative to rail shipment.
CORRECTION: A previous version of this post misidentified the oil in the Quebec train derailment in July as "heavy crude."