Propane

Bakken crude is considered more volatile than other types of oil, which presents a safety problem when moved by rail. New regulations approved Tuesday require oil producers to separate flammable and volatile liquids prior to shipment by rail.
Dec 11, 2014   The New York Times - Energy & Environment
Propane prices in some parts of the midwest and south had tripled; governors have demanded investigations into price gouging, and shelters have opened for those unable to afford the steep prices increases, yet production increased 15% from last year.
Feb 10, 2014   The New York Times