First, a note of introduction. Until recently, I was a computer
security guy, and as with many in my profession, the application of
computer security analysis to non-computer security problems was
increasingly interesting to me. Now, for reasons that don't need
exploring at this juncture, I'm back at school, studying chemistry,
and I'm spending this summer in a lab doing organic synthesis
work. Strangely, today I find my interests colliding.
So, I'm doing a bunch of reading, and I find the claimed method the
"highly sophisticated" attackers came up with for bringing down
airliners kind of implausible. I wonder if it could ever work in
reality.
A disclaimer, I'm working entirely off of news reported by people who
don't know the difference between soft drinks and nail polish remover,
but the information I've seen has the taste of being real. As near as
I can tell, it is claimed that the terrorists planned to make organic
peroxides in situ on board an airplane and use them to destroy the
plane.
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:
http://www.mne.umd.edu/LAMP/Sop/Piranha_SOP.htm
Now you may protest "but terrorists who are willing to commit suicide
aren't going to be deterred by being injured while mixing their
precursor chemicals!" -- but of course, determination isn't the issue
here, getting the thing done well enough to make the plane go boom is
the issue. There is also the small matter of explaining to the guy
next to you what you're doing, or doing it in a tiny airplane bathroom
while the plane jitters about.
Now, they could of course mix up their oxidizer in advance, but then
finding a container to keep the stuff in that isn't going to melt is a
bit of an issue. The stuff reacts violently with *everything*. You're
not going to keep piranha bath in a shampoo bottle -- not unless the
shampoo bottle was engineered by James Bond's Q. Glass would be most
appropriate, assuming that you could find a way to seal it that
wouldn't be eaten.
So, lets say you have your oxidizer mixture and now you are going to
mix it with acetone. In a proper lab environment, that's not going to
be *too* awful -- your risk of dying horribly is significant but you
could probably keep the whole thing reasonably under control -- you
can use dry ice to cool a bath to -78C, say, and do the reaction
really slowly by adding the last reactant dropwise with an addition
funnel. If you're mixing the stuff up in someone's bathtub, like the
guys who bombed the London subways a year ago did, you can take some
reasonable precautions to make sure that your reaction doesn't go
wildly out of control, like using a lot of normal ice and being very,
very, very careful and slow. You need to keep the stuff cool, and you
need to be insanely meticulous, or you're going to be in a world of
hurt.
So, we've covered in the lab and in the bathtub. On an airplane? On an
airplane, the whole thing is ridiculous. You have nothing to cool the
mixture with. You have nothing to control your mixing with. You can't
take a day doing the work, either. You are probably locked in the
tiny, shaking bathroom with very limited ventilation, and that isn't
going to bode well for you living long enough to get your explosives
manufactured. In short, it sounds, well, not like a very good idea.
If you choke from fumes, or if your explosives go off before you've
got enough made to take out the airplane -- say if you only have
enough to shatter the mirror in the bathroom and spray yourself with
one of the most evil oxidizers around -- you aren't going to be famous
as the martyr who killed hundreds of westerners. Your determination
and willingness to die doesn't matter -- you still need to get the job
done.
You also need quite a bit of organic peroxides made by this route in
order to be sure of taking down a plane. I doubt that just a few grams
is going to do it -- though of course the first couple of grams you
are likely to go off before you make any more. The possibility of
doing all this in an airplane lav or by some miracle at your seat
seems really unlikely. Perhaps I'm just ignorant here -- it is
possible that a clever person could do it. I can't see an easy way
though......
Source/read the rest of the article.