With some gases, they are extremely dangerous to store, as the accidents in Utah back in the 60s shows.
To make it safe, the US government during the mid 60s began working on what is called a binary toxin. It is breaking the dangerous molecule into two inert (Or at least non toxic) molecules, with a binder that causes them to reform when combined. The weapon is loaded into a shell or bomb, and when it is fired or dripped the spinning of the shell (Or artificially induced spinning in a bomb) mixes it before release.
I read a book named Binary (They made a movie with Ben Gazzara back in the 70s, though i can't remember the name) where Stephen Lange (I think that was the author, not sure about his first name) waxed lyrical after someone stole about a ton of it.