Is it true that Bakken oil contains up to "30 to 40 percent" "explosive volatiles", and why are the contents of oil trains witheld even from first responders

"The rail industry has enjoyed a long history of legal protections, allowing it to operate in secrecy with regards to carrying hazardous materials. Indeed, Big Rail pushed hard to fight the release of information to the public on the transportation of Bakken crude oil. 

This time around, the rail industry said that information it was compelled to give the federal government on its Bakken oil shipments under the U.S. Department of Transportation’s (DOT) May 7 Emergency Order could not be released to the public under state-level open records laws.

Why? Because it fell under the category of 'sensitive security information.' 

In boilerplate letters and contract proposals sent to heads of State Emergency Response Commissions - one of which was obtained via Idaho’s Public Records Act by DeSmogBlog - BNSF deployed this argument.  

This legal designation means BNSF and other companies could withhold information regarding the movements of Bakken crude from the public — by exempting it from state-level open records laws — and would only have to release it to the emergency response commissions." - "For Oil by Rail, the Battle between "Right to Know" and "Need to Know" - Desmogblog

-Not that they did so. Oh, and threats work

"Battle Over New Oil Train Standards Pits Safety Against Cost" - NPR