As I predicted in a comment at Little Green Footballs a week ago, the action line in the left side of the mainstream media has shifted from “not real” to “not feasible” after the police have disclosed evidence, including matyrdom videos from the failed terrorists. In the UK Register we have a very authoritative appearing article spouting all the myths about binary liquid explosives. Authoritative sounding when it’s not sneering and joking about mass murder that is.
We’re told that the suspects were planning to use TATP, or triacetone triperoxide, a high explosive that supposedly can be made from common household chemicals unlikely to be caught by airport screeners. A little hair dye, drain cleaner, and paint thinner – all easily concealed in drinks bottles – and the forces of evil have effectively smuggled a deadly bomb onboard your plane.
Or at least that’s what we’re hearing, and loudly, through the mainstream media and its legions of so-called “terrorism experts.” But what do these experts know about chemistry? Less than they know about lobbying for Homeland Security pork, which is what most of them do for a living. But they’ve seen the same movies that you and I have seen, and so the myth of binary liquid explosives dies hard.
 The article gets several things dead wrong. The real truth can once again be found on Jerry Pournelle’s Blog, from John Carmack, a rocket scientist. Below from the letter John Carmack wrote to Thomas C Greene, which is a thorough fisking of his entire article:
I’m usually in the position of trying to use basic statistics and common sense to combat fear-mongering about the dangers of terrorism, but I have to tell you that you are just plain wrong about the impracticality of binary liquid explosives.
I worked with concentrated peroxide for years at Armadillo Aerospace, and I can tell you with 100% certainty that you can reliably mix two clear liquids and get a high explosive that can be detonated by a sharp impact.
TATP is an unstable molecule that can slowly form in acetone / peroxide mixtures, even fairly dilute ones. Synthesizing and purifying that is probably something better done in a lab, but a simple solution of concentrated peroxide and acetone (or any other soluble fuel like methanol or ethanol) is also an explosive that is just as powerful. Many explosive, like gunpowder or ANFO, are not compounds at all, but simply mixtures of oxidizers and fuels.
You do need concentrated peroxide to do this, the common 3% peroxide from the drug store won’t cut it. We have first hand data points at a couple of these concentration levels, but there are some papers available that map out the sensitivity / concentration / mixture ratio diagrams with a lot more tests.
- 50% peroxide / fuel mixtures won’t detonate, even with a blasting cap. We used a very large amount of this safely as a rocket propellant, which does demonstrate that just mixing them is not hazardous.
- 60% peroxide / fuel mixtures can be detonated with a blasting cap. A blasting cap would probably be caught by explosive sniffing equipment, so it probably wouldn’t be useful for terrorists.
- 85% peroxide / fuel mixtures can be detonated by modest impacts. Shaking a plastic bottle of mixed solution with a few ball bearings in it would probably do it.
- 98% peroxide / fuel mixtures can be detonated by static electricity.
