Most Flammable Substance

A lot of things burn with astounding intensity; Styrofoam, napalm, marshmallows are just the beginning. But what if there was a material that could set sand on fire? Okay, so clearly that was a loaded question, but it was a necessary set-up. Chlorine triflouride has the dubious honor of being terrifyingly flammable, to the point that history’s evil boy-scouts, the Nazis, deemed it too dangerous to work with. When people who consider genocide their life’s goal don’t want to use something because it is too deadly, it bears treating it with some caution. There is a story that a ton of the stuff was spilled once and caught fire, and it burned through 12 inches of concrete and another meter of sand and gravel before going out.