Boy, I just listened to the hourly NPR news about the TX blast. It quoted a DHS official as claiming the anhydrous ammonia stored under pressure in tanks on site were what exploded. That's total bullshit, any check of Wikipedia would demonstrate that. It can be flammable under certain circumstances - and a leak in the line may have been responsible for the original fire - but it doesn't blow up like a McVeigh truck bomb or small nuke.
I got a live feed from a Waco station beginning about 11 pm last night when I first heard about the explosion. The station had people on-site and a helicopter, it was dedicated coverage. That would have been 10 pm Texas time, just a couple of hours after the big blow. They carried an interview with some plant official (don't know if it was an owner), who expressed sincere shock that the explosion was so huge. Duh. Like he believed the PR that the plant wasn't dangerous, which is no doubt why the town built a school, apartments and a nursing home next to it.
Anyway, from the helicopter above the factory the situation was being explained. The tanks of liquid anhydrous ammonia were to the right of the frame. Pretty dented, but intact. The explosion, they explained per info given by the company guy, happened on the other side of the facility - to the left of the frame - where the dry ammonium nitrate fertilizer was stored. The factory apparently used the anhydrous ammonia for the chemical process of making ammonium nitrate fertilizer. It was not said whether or not the dry fertilizer was stored inside or outside the plant, but it's spring and as a supplier to area farmers they had quite a lot of it on hand.
Per Wikipedia, under "Production" -
The processes involved in the production of ammonium nitrate in industry, although chemically simple, are technologically challenging. The acid-base reaction of ammonia with nitric acid gives a solution of ammonium nitrate...
For industrial production, this is done using anhydrous ammonia gas and concentrated nitric acid. This reaction is violent and very exothermic. After the solution is formed, typically at about 83% concentration, the excess water is evaporated to an ammonium nitrate [AN] content of 95 to 99.9% concentration [AN melt], depending on grade. The AN melt is then made into "prills" or small beads in a spray tower, or into granules by spraying and tumbling in a rotating drum. The prills or granules may be further dried, cooled, and then coated to prevent caking. These prills or granules are the typical AN products in commerce.
...and the end product of the factory in question. Under the heading of "Safety, handling and storage" -
Heating or any ignition source may cause violent combustion or explosion. Ammonium nitrate reacts with combustible and reducing materials as it is a strong oxidant. Although it is mainly used for fertilizer it can be used for explosives. It was sometimes used to blast away earth to make farm ponds. Ammonium nitrate is also used to modify the detonation rate of other explosives. Examples will be ammonia dynamites [Nitroglycerin].
Nope. No danger to the general public there! Good grief. Why Homeland Security is fudging the facts the following morning is a mystery to me. I mean, wouldn't their 'experts' know which of these ammonia compounds is explosive and which is not? Timothy McVeigh knew the difference, obviously. Lots and lots of other people do too.
I'd hate to think that DHS would deliberately lie to the public about this incident, but the fact is they are not telling the truth. Surely it couldn't have anything remotely to do with how this factory has steadfastly presented itself to the public it has now devastated as "No Danger To The General Public." It's been there for 40 years. That was BEFORE the town allowed a school, a nursing home and an apartment complex to be built right damned next to it.
I don't know and wouldn't hazard a guess as to whether this disaster was somehow deliberate (arson?) or the supposedly "controlled burn of loose pellets" I've also seen reported this morning. Which is also bullshit, for many other reasons. But this stuff is NOT that difficult to figure out, and officials of Texas and DHS and OSHA and whatever negligent regulatory agencies are out there can do a Google as easily as I can. They are lying about the disaster at this point in time, were not lying about it within just a couple of hours of the explosion last night.
Why is that? I mean, it's not like people don't know or can't find out about "fertilizer bombs" and how they've been put to bad use over the years. These lies are transparent mumbo-jumbo as totally UNscientific as claims that GW isn't real or the earth is 6,000 years old. Religion does not trump chemistry. This is chemistry.
WTF is going on??!?
UPDATE 4/19: NBC News Reports today that the West Fertilizer distribution center reported to the state in February that it was storing 270 tons of ammonium nitrate fertilizer on site, along with "up to" 110,000 pounds [55 tons] of liquid anhydrous ammonia in its tanks.
Also, the report notes that this facility did not produce fertilizer, it merely stockpiled fertilizers for distribution to area farmers, and had a workforce of 8 people, no nighttime security, and no safety systems installed. First responders in the town had apparently not been told that there was AN fertilizer on site, they believed the less volatile liquid anhydrous ammonia was the most dangerous substance at the warehouse.
The company had insisted nothing at the plant presented fire or explosive hazard, described their "worst case scenario" as total release of one anhydrous ammonia tank as gas (which is poisonous) over a 10 minute period, indicating how quickly liquid anhydrous ammonia transitions from pressurized liquid to lighter than air gas.
For comparison purposes, Timothy McVeigh totalled the Murrah federal office building in Oklahoma City with 3 1/4 tons of AN fertilizer mixed with fuel oil in a rental truck. 270 tons is considerably more.