Went here for one last perusal before bed. It's about chlorine triflouride (ClF3) which has just become The Most Awesome Chemical in my mind because of an anecdote about a chemical spill related in this PDF.
"One eyewitness described the incident by stating, 'The concrete was on fire!'"
Quoth the first link:
The compound also a stronger oxidizing agent than oxygen itself, which also puts it into rare territory. That means that it can potentially go on to "burn" things that you would normally consider already burnt to hell and gone, and a practical consequence of that is that it’ll start roaring reactions with things like bricks and asbestos tile.That's just incredible. And you don't want to be in the same room when it's doing this stuff, either, because one result of the reaction is hydrogen flouride: bubble it through water and you have hydroflouric acid, which is a pretty powerful acid. Yeech etc.
The writer of that blog quotes someone else: "For dealing with [a metal-flourine fire], I have always recommended a good pair of running shoes."
In short, be afraid of this stuff.
There are plenty of chemical compounds I already know I want nothing to do with: nitrogen tetroxide, red fuming nitric acid, and monomethyl hydrazine just to name a few, all of which are highly toxic, corrosive, and which will ruin or cancel your day if you come in direct contact with them. Chlorine triflouride is just the latest addition to the list.