Monkeywrenching airport security

[Eugene Leitl]

On Sat, 17 Nov 2001, David Honig wrote:

> At 10:57 AM 11/17/01 -0800, Sandy Sandfort wrote:
> >Airport chemical "sniffers" apparently look for the signature of nitrogen
> >compounds, not "explosives," per se.  I've often wondered how many weekend

Unless they look for nitrogen in bulk of the specimen (PGNAA), a very
expensive/low-processivity technique unsuitable for mass luggage screening
they're limited to stuff stuck to surfaces (lasers, swabbing/ion motility
spectrometer)  and volatile sniffers (chemical sensors, canines).

Many classes of explosives contain no nitrogen, many of those which
contain nitrogen and are free of volatile tracers don't emit much
volatiles, if properly packaged even very volatile explosives (say, methyl
or ethylnitrate) can be sealed (glass bottles). Generally, the maker and
the packager, unless they work very cleanly/are suited should not be the
courier, nor the outer containers be present in the contaminated area.

In short, detection probability is only high for sloppy/dumb people.

> >gardeners have gotten hassled and delayed because of trace amounts of
> >ammonia-based fertilizers on their person and effects.  If you plan to fly,

Salts are different from traces of uncombusted nitrocellulose deposited on
any surface of a nearby gun being fired.

> >be sure to wash your hands thoroughly before heading out for the airport if
> >you have been shoot, gardening or house cleaning.
>
> I've wondered about that too; airport sniffers must have encountered
> Miracle Gro and angina nitro during the early days, measuring

Nitroglycerin is not volatile, is present in large dilution (~0.1%) in
small quanitities (pharma bottle). Ditto nitrate salts in a water
solution.

> a false alarm rate.  Shooting is scary; you could contaminate
> your car driving back from the range, then contaminate your
> travel gear.

I think you should be able to get a good positive if you'd fire several
rounds of vanilla smokeless with baggage surface being near the muzzle
of the gun. Try it sometime, if you're unafraid of winding up in a
database. I've found that transporting computer parts (motherboard) in
hand luggage can suffice to trigger swabbing (if you're really bored you
can discuss detection of Semtex traces with airport security).

> The explosives expert in one of the older terror trial docs on cryptome
> says things suggesting that a few washes will remove traces.  (And contaminate
> clothes washed with them.)

Just use an overall when you're at the range, and wash it separate.

> I once checked out the screen on a sniffer, and they list "nitrates"
> as a category.  I suppose having PETN (another category) detected
> on your laptop would be harder to explain :-)

If you want to fool the security, you should become familiar with the type
of detectors used on your luggage. Of course, best solution is using human
factors to not have your stuff being screened at all.

-- Eugen* Leitl <a href="http://www.lrz.de/~ui22204/">leitl</a>
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