An in-depth view on the implausibility of the recent liquid explosive threat

(via Freedom to Tinker)
Standard air terrorism disclaimer – skip ahead if you don’t care.

There is a very good write-up over at Interesting-People about the recent terrorism threat on UK planes scheduled for the US. The author does some analysis based on what we’ve been told of the planned attacks. In the end, he questions the effectiveness of the plan, and notes how difficult it would be to even make such an attack succeed. One point I really want to bring out here is one of the ingredients of the believed liquid explosive is found in nail-polish remover. That may well explain why that was one of the targetted items specifically mentioned in some recent not-allowed lists.

The author starts with a personal introduction, and then explains, as I have noted above, that all this is speculation based on the information on the attacks that is currently available to the public.

This seems, at least given my initial examination of the idea, implausible.

Based on the claims in the media, it sounds like the idea was to mix H2O2 (hydrogen peroxide, but not the low test kind you get at the pharmacy), H2SO4 (sulfuric acid, of necessity very concentrated for it to work at all), and acetone (known to people worldwide as nail polish remover), to make acetone peroxides. You first have to mix the H2O2 and H2SO4 to get a powerful oxidizer, and then you use it on acetone to get the peroxides, which are indeed explosive.

A mix of H2O2 and H2SO4, commonly called “piranha bath”, is used in orgo labs around the world for cleaning the last traces out of organic material out of glassware when you need it *really* clean — thus, many people who work around organic labs are familiar with it. When you mix it, it heats like mad, which is a common thing when you mix concentrated sulfuric acid with anything. It is very easy to end up with a spattering mess. You don’t want to be around the stuff in general. Here, have a look at a typical warning list from a lab about the stuff:

Before anyone jumps in and says “Terrorists. Suicide. Exploding plane. Blah, blah, blah,” he is not talking about whether or not they would do this and be exposed to the bubbly mess. He is discussing the likelihood of mixing this well enough to go boom, or even well enough to do more than harm those mixing the fluids – whether they could do this. The mixing process is difficult enough to do in a lab that it seems exceptionally improbable to do in a plane lavoratory or worse yet in one’s seat. So he gets through the explanation of why this is implausible, then goes to the conclusions he draws from the experience.

  1. The terrorists had a brilliant idea for how to combine oxidizer and a ketone or ether to make some sort of nasty organic peroxide explosive in situ that has escaped me so far. Perhaps that’s true — I’m not omniscient and I have to confess that I’ve never tried making the stuff at all, let alone in an airplane bathroom.
  2. The terrorists were smuggling on board pre-made organic peroxide explosives. Clearly, this is not a new threat at all — organic peroxide explosives have been used by terrorists for decades now. Smuggling them in a bottle is not an interesting new threat either — clearly if you can smuggle cocaine in a bottle you can smuggle acetone peroxide. I would hope we had means of looking for that already, though, see below for a comment on that.
  3. The terrorists were phenomenally ill informed, or hadn’t actually tried any of this out yet — perhaps what we are told was a “sophisticated plot” was a bunch of not very sophisticated people who had not gotten very far in testing their ideas out, or perhaps they were really really dumb and hadn’t tried even a small scale experiment before going forward.

And finally, he discusses some of the security theatre behind the entire handling of the situation and points out other improbable terrorist attacks as well as the appropriate responses to these. Let me just tell you that in the end he suggests we not be allowed to take luggage – even checked – and that we all fly naked after going through body cavity searches before the flight. That pretty much reduces the scare down to someone travelling with a bomb actually surgically implanted in their body.

[tags]On the recent terrorist attacks, The implausibility of the liquid explosives threat[/tags]