Maybe, but how big of an explosion could 400 lbs of ammonium nitrate make?
I don’t know. Not my specialty, I don’t know how much McVeigh used in OKC. I think he used quite a bit more. As mentioned above, it comes in 100 lb bags, and four bags is a pallet rounding error in a factory, which is my point.
Makes no sense to write up a facility for an amount the janitor sweeps up at the end of a shift, unless one is looking for a scapegoat.