...that grips al-Reuters, AFP, AP, and the rest of them: "Potassium nitrate can be used to make explosives and to power homemade rockets. It can also be used as a fertilizer".

For f**k's sake, Potassium Nitrate is fertilizer. If you're a terrorist, you may want to use it as an oxidizer, but it is meant for use in intensive farming. It's a pity the Gaza farmers can't get any of it, because it can make a difference between getting a modest profit from lots of hard work, and catastrophic loss for insufficient yield/quality.
I sincerely hope the Gaza farmers can get alternative, non-explosive Nitrogen fert such as Ammonium Sulphate or Urea.
They are knowledgeable and skillful enough to be able to use these rather more technical substances, which need to be sprayed on the crop at the appropriate times and at the right concentrations, or applied in a composting process.

The fact that the fertilizer was in bags marked sugar shows their intended purpose.

Also I would be carefull about putting sugar into my coffe if I were Palestinian, you might end up drinking fertilizer.

It would make sense to provide the alternative fertilizer through the EU aid program, though more thoroughly checked.

Toulouse, 2001, Oklahoma City, 1995...

If I understand the article correctly

The EU did not send the Palestinians fertilizer, but sugar in those bags. The Palestinians then used the bags marked sugar to smuggle chemicals for explosives.

Better send the next batch of goods in transparant plastic bags.

The Toulouse AZF event in 2001, in which ~40 people died, has been classified as an industrial accident as well following the French gov't inquiry. Some say a genuine terrorist attack has been covered up, but can't prove it.
Such behavior would not, however, be entirely surprising on behalf of the Chirac administration.

My understanding is that Nitrate ferts are now formulated to prevent both explosions and hygroscopic deterioration, but the stuff that blew up was most likely raw, unformulated Ammonium Nitrate.
Nitrate ferts are invariably granulated to allow their dispersal in the field by rotating-disk machines, and look nowhere like crystalline Sucrose. Clear polyethylene sacks might be a good idea, but changing the packaging specs of bulk F.I.'s such as sugar is no trifling matter. In Israeli f&b factory courtyards, I've seen sugar coming in from abroad in large, squat, cylindrical 1 metric Ton bags made of a sturdy white, woven polyethylene sacking fabric. A transparent material as strong as that, which would hold that much weight while hanging from a crane, would no doubt be very expensive. Think Polyamide, but really, really thick...

I should think it's an anaphrodisiac.  I would have my date most disturbed if I learned someone had spread it all over the chair I was sitting on.
But, saltpeter? You can get that from any decayed biological product. The Bourbons used to have agents go round to gather it from farmers' stables. No doubt these were not the ones in great favor at Versailes.
I find it hard to believe that Palestinians can't get a hold of it themselves. Palestinians aren't famous for day to day technical ingenuity but surely they know how to gather saltpeter from their from their own sources.