It's neurotoxic, a respiratory irritant, and an eye irritant.

No, if it's injected in your bloodstream it won't immediately kill you, but if you inhale a few milligrams of vapor you'll wish you could cough up a lung.

Also, the vapors are heavier than air, so if you fall in a ditch near the hypothetical blown tank you would likely suffocate and die.

It is however highly flammable and potentially explosive when sealed in a tank, which is the main concern.

And then we need to consider the byproducts produced when it burns - both nominally as well as the sort of extremely dirty incomplete combustion an explosion would produce.