A friend with a doctorate in chemistry sent me the following:
"According to the official government story, TATP (triacetone triperoxide) was the explosive these conspirators were planning to manufacture aboard the airliners.
"This story is not plausible for a number of reasons, but let's take a quick look at just enough of the science so as not to provide anybody with a guide to making an actual bomb: TATP is made from hydrogen peroxide solution, acetone and sulfuric acid. The reaction can be carried out with just about any concentration, but is best done with concentrated solutions of both peroxide and acetone.
"The peroxide and acetone can be pre-mixed, but the acid must be added, a drop at a time, to the solution, all the while continuously stirring it and keeping it continuously chilled. This step of the process will take several hours, during which the fumes given off will be substantial and quite overpowering, thus a lab-quality air evacuation system is required. (ES: right here, the whole idea of a TATP bomb becomes ludicrous. Difficult in a lab, but impossible in an airplane due to the environment - the toilet - and the time requirement.)
"One then must let the resulting solution stand for an extended period at temperatures above the freezing point, but definitely below 10 Celsius (50 Fahrenheit). Above 10 Celsius, the TATP does not form; instead, diperoxide forms, which is so unstable it cannot be worked with. The time required for the reaction to go to completion is at least 24 hours and often several days.
"Once the TATP forms, it crystallizes as snowflakes from the solution and must be harvested by filtration and the liquid discarded. The TATP then is dried and carefully stored until needed. It must be stored below 10 Celsius or it converts spontaneously to the unstable diperoxide.
"There is neither the time, the workspace nor the other materials required to make TATP on an airliner. The time required, the temperatures required, the workspace required and the need to dry the chemical prior to use preclude this story being reasonable. This chemical process is much more sensitive than making, for example, nitroglycerin."
The technically proficient reading this will recognize that a necessary step has been omitted and some others have been altered in critical ways. None of these purposeful camouflages alter the ingredients or the time, care and equipment required. Nor will I describe how TATP can be fabricated beforehand and then detonated aboard an airliner in flight. After all, though we want to demonstrate the impossibility of what has been claimed, we don't want anybody actually trying this at home - and there really are some genuine whack jobs out there. After all, we elect some of them to public office.* The entire text above is from a Nickel Rant (tm) by Edgar J. Steele. Thomas C. Greene's article (http://www.theregister.co.uk/2006/08/17/flying_toilet_terror_labs/) is also worth a read.
** The links above were provided to me by Satanical Susan, lurker extraordinaire, who emails me stuff from time to time. BTW, Diogenesian Surfer, if you're reading this, your contributions are welcome too.