Our local news station did a piece on the dangers of “explosive fertilizer” last night, revolving around the story on the explosion on the fertilizer plant in Texas. The anchor kept patting a bag of 21-0-0 Ammonium Sulfate, which is neither flammable or explosive under any circumstances.
He probably was not readily able to buy a bag of 34-0-0 Ammonium Nitrate on short notice, because farm supply stores keep it in the back room and want identification before they will sell it to you. They do that not because it is dangerous per se, but because if someone buys enough of it they could use it to build a bomb. If someone was storing several dozen tons of it and set the building on fire, there could be an explosion.
That being said, one thirty pound bag of it in your garage is about as dangerous as your average house cat. The main danger is that it will absorb water from the air and turn into a liquid, useless and modestly toxic mess. Despite our guy’s warnings about “handling it carefully,” you can jump on it, hammer it, drop things on it… One thirty pound bag is not going to explode under any circumstances. Just keep it sealed up tight, not because, as he warns, it is going to kill you with toxic fumes, but to keep it dry.
Better yet, use the Ammonium Sulfate which he had on his desk, and just use more of it. They both contain nothing but nitrogen, but the supposedly deadly Ammonium Nitrate has more of it in one bag because the nitrogen is more concentrated. Using the lower concentration in larger amounts is just as effective, and you don’t have to worry about it getting damp and self destructing into a useless mess.
And you don’t have to worry about FBI agents asking questions.