Mislabeled oil may have been the root cause of the Canadian train explosion in July, Canadian Transportation Safety Board (TSB) officials claimed, WebProNews reported Wednesday.

According to officials the oil carried by the freight train that got derailed and exploded in Lac-Megantic, Quebec in July was misclassified as the less dangerous kind of crude.

The said July disaster left 47 people dead and a large part of the downtown area near the Maine border was destroyed, ABC News reported.
Canadian TSB Chief Investigator Donald Ross said that the North Dakota oil was mislabeled as "Group 3" flammable liquid, when it should have been labeled as a more explosive "Group 2" kind.

Previous reports stated that the authorities were first surprised by the unexpected explosion, but Ross clarified the oil was as dangerous and as volatile as gasoline, adding that oil testing was incorrectly documented prior to the shipment.

When asked if proper labeling would have changed the disaster, Ross answered that the work of the board isn't over yet.The Canadian TSB then issued safety advisory letters to the U.S. Pipeline as well as to the Hazardous Materials Safety Administration and to Transport Canada.

Consequently, the federal Railroad Administration as well as the Pipeline and Hazardous Materials Safety Administration responded to the letters right away, saying that they are currently looking into any misclassifications of crude oil shipments.

"Shippers and rail carriers found to be out of compliance with hazardous materials regulations could be fined or placed out of service," they added through the statement.

Ross said that although the train was operated by an American company, the responsibility on the labeling of imported goods falls under the New Brunswick Irving Oil Co. in Canada.

Meanwhile, Canadian Transport Minister Lisa Raitt asked the Transport Canada officials to respond quickly to the board's safety advisory. "If a company does not properly classify its goods, they can be prosecuted under the Transportation of Dangerous Goods Act," Raitt added.

WebProNews reported that this is actually the second time since the train derailment accident that the Canadian TSB has issued advisory on the proper identification and documentation of hazardous materials.

The first advisory was released two weeks after the incident, when the Canadian TSB had asked Transport Canada to ensure "that trains carrying dangerous goods are not left unattended on the main track."

Further investigations on the incident are still ongoing.