Is Bakken crude more volatile than other kinds of oil?

The Wall Street Journal takes note of an issue that’s growing in importance: Whether crude from the Bakken oil-shale formation is more volatile, and explosive, than other kinds of crude oil that comes out of the ground.

The geological makeup of the oil is crucial to regulators who are in the process of deciding whether to impose additional restrictions on companies that transport Bakken crude by railways.

The WSJ story begins:

Regulators set to decide on crude-by-rail shipping rules are relying on testing methods that may understate the explosive risk of the crude, according to a growing chorus of industry and Canadian officials.

The tests’ accuracy is central to addressing the safety of growing crude-by-rail shipments across the continent: whether Bakken crude contains potentially dangerous levels of dissolved gases. Several trains carrying Bakken crude have exploded after derailing, including a fiery accident last year that killed 47 people in a small town in Quebec.

The North Dakota Industrial Commission is expected to decide Thursday whether to impose new rules on transporting oil on railroads. A study by the state’s Petroleum Council concluded that Bakken crude was no more volatile than other light crudes found in Texas and other fields. But the testing that went into that report might have allowed flammable gases, called light ends, to escape before the samples were collected and processed.

The U.S. Department of Transportation also has proposed new safety rules for oil by rail, including phasing out the aging tanker cars (called DOT 111) used to transport the oil within two years.