Federal officials probing the Lac-Mégantic disaster are testing the chemical composition of crude oil carried by the runaway train as they seek to answer the crucial question of what triggered the unusual and devastating explosion after the derailment.
Transportation Safety Board investigators are collecting oil samples from each of the 72 rail cars that hurtled down a hill into the small Quebec town and ignited an enormous fireball that levelled more than 40 buildings and, as of the latest count, has killed 42 people.
Edward Burkhardt, chairman of Montreal, Maine & Atlantic Railway Inc., which operated the derailed train, said Canadian authorities have impounded the rail cars to take "a huge number of samples of oil." He said the investigators and officials in the rail and oil industries "are asking how come there were explosions here. Crude does not blow up."
People familiar with the investigation said the TSB is examining the composition of the oil that fuelled the explosion.
Industry sources said there are several possibilities. One is whether the crude, which came from the Bakken oil region of North Dakota, contained volatile chemicals. A possible scenario is that additives were intentionally combined with the crude oil to speed up the transfer of the syrupy oil, common for pipelines but rare in the rail industry. Another possibility is that the tanker cars had chemical contaminants from a previous shipment. Another question is whether the oil contained high levels of flammable hydrogen sulphide gas, which is sometimes present in Bakken oil.
Mr. Burkhardt, who is one of several private and institutional shareholders that own the small east coast railway, has said he is devastated about the Lac-Mégantic catastrophe, and that it began after one of the company's employees neglected to apply enough hand brakes to the train on the night it broke away. Despite this failure, he said, a broader question needs to be asked about whether railways or regulators need more information about the chemical content of oil that is being transported on the rails.
"There are questions in the industry as to whether, in fact, the oil is mislabelled when it comes to its qualities. When the Transportation Safety Board issues its report, it is going to be hundreds of pages, and a huge amount of it will be devoted to chemical composition – where this stuff came from and what to do about it," he said.
Mr. Burkhardt said he also expects investigators look to see if a local propane tank might have been detonated by the impact of so many heavy oil cars in a confined urban area and triggered the larger explosion. He disputed earlier media reports that there was a propane tanker in the vicinity of the derailment.
Although MM&A has accepted responsibility for the derailment, the potentially volatile chemical makeup of the Bakken oil is becoming a subject of increasing controversy in the transportation sector.
Some oil extracted from the Bakken fields has been found to contain high levels of the foul-smelling hydrogen sulphide vapour, which is flammable, corrosive, poisonous and explosive. The gas is formed below ground when organic matter breaks down in the absence of oxygen.
Another question is whether the oil contained high levels of flammable hydrogen sulphide gas, which is sometimes present in Bakken oil.
Although hydrogen sulphide is a common impurity in oil and gas extraction, there is a debate over whether Bakken crude contains dangerous levels of it. In May, pipeline operator Enbridge Inc. filed regulatory documents to the U.S. Federal Energy Regulatory Commission seeking permission to refuse to ship Bakken crude with extremely high levels of hydrogen sulfide through its pipelines. Enbridge said in a submission to the commission that it wanted to ensure "the safe operation of its system and the health and safety of its employees."
Some observers are also questioning whether high temperatures in Quebec the day before the crash made the oil more flammable.
John Cottreau, a spokesman for the TSB, said the regulator is still collecting and analyzing crude samples at Lac-Mégantic. It is expected that it will be months before the regulator issues its report.
Transport Canada is also probing the explosions in a separate investigation.
"Transport Canada has obtained a warrant and is gathering evidence to determine if rules and regulations under the Railway Safety Act and the Transportation of Dangerous Goods Act have been followed," a spokeswoman for the department said in an e-mail.
She would not elaborate on the contents of the warrant, which is sealed. Non-compliance with federal regulations could lead to criminal charges.
The derailed train was carrying crude from oil fields in the northwest corner of North Dakota to an Irving Oil refinery in Saint John, N.B.
Regulators in the United States say rail carriers are responsible for knowing what they are carrying, and that the shipper and the railway company are required to work out such details when the train is being loaded.
"The carriers have to know exactly what it is that they're hauling at all times," said Warren Flateau, a spokesman for the Federal Railway Association in Washington.
Mr. Burkhardt said MM&A received a detailed bill of lading from the U.S. oil services company, which he declined to identify, and no chemicals were identified as being present in the crude. The intermediary oil services company leased the rail cars, loaded them with oil and then contracted three separate railway companies to transport them.
The first carrier was Canadian Pacific Railway, which handed over the train to MM&A in Montreal. From there, MM&A was to deliver the oil cars to a small rail company in New Brunswick owned by the Irving family.
According to people familiar with the Lac-Mégantic train shipment, the company that bought and loaded the leased rail cars was World Fuel Services Corp., a publicly traded company based in Miami. A spokeswoman for the company did not return phone.
In response to questions about the safety of the Bakken crude on the derailed train, a Canadian Pacific spokesman said in a statement that "CP meets or exceeds all federal operating and safety regulations and rules. As we do on an ongoing basis, the recent tragedy allows us to review our safety procedures in an effort to identify any potential opportunities for further improvement."