Judith,
Glacial Acetic Acid is not unstable or explosive and is not very toxic.
But it vaporizes readily and the vapors are irritating to mucus membranes
(eyes, nose, lungs).
The reason that it is transported in waterfilled containers is to quickly
dilute the acetic acid to the concentration of vinegar if an acid container
should break or leak.
Jim
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>I'm betting a load of manure would not only be cheaper than glacial acetic
>acid but also easier to get--glacial is pretty unstable stuff. We used it
>at University to dilute for dyeing fibers and had to haul it in
>waterfilled containers to guard against jolts. I've never heard of a load
>of manure exploding when going over a pothole!