The dangers of AMFO are both overrated and underrated.
1. There are two basic forms that ammonium nitrate is supplied in. One is
fertilizers, which are not very good for use as an explosive, because the
prills (pellets) are coated to prevent it from absorbing moisture. (this
coating also prevents it from absorbing fuel.) The other is specifically
designed for use as a cheap explosive and doesn't have this coating, and the
prills are slightly different so as to contain about 20% empty space.
2. Ammonium nitrate is an oxidizer, and when transported is placarded as
such, not as an explosive etc. Being an oxidizer means that under most
conditions it must be mixed with a fuel to burn or explode. If large
quantities are confined, it can decompose and explode, an example would be
tons of it in a ships hole.
3. Diesel oil, fuel oil, and kerosene are the most common fuels mixed with
it to make a cheap commercial explosive. But other things such as molasses,
nitro methane, wax, etc can and have been used.
4. AMFO is usually about 92-93% ammonium nitrate with the rest being fuel.
AMFO is very hard to detonate, especially with civilian type equipment. With
civilian blasting caps a supplemental decanter (usually dynamite) is
required. (And even then there are failures.)
5. As ammonium nitrate absorbs water vary easily, especially non-coated type
used for explosives. Once it has absorbed moisture it is useless as an
If the ammonium nitrate and fuel have been mixed for any length of time then
it is probably only a fire hazard. Emptying the truck and giving it a quick
rinse inside and out with water should eliminate most of the problems.
However plan it this way. If worst comes to worse, (but you do survive), how
will you explain this to the insurance company?
I would have the truck emptied and cleaned.
As it is about 4am here and I haven't been asleep yet, I don't know if this
makes any sense or not.