Extensive testing behind new TSA liquid container rules

It turns out Kip Hawley might not be an idiot after all. Last week we reported on a cynical businessman who, while moving through a checkpoint at the Milwaukee airport, took a felt-tip marker to his regulation quart plastic bag in order to impune the intelligence of the TSA chief. Hawley, the man believed, had no basis for a new rule permitting small amounts of liquids onboard so long as they were placed in a ziplock bag first, and he wanted to say so. As readers may recall, security officials detained the man and then told him his first amendment rights did not apply in screening areas. This was not a correct statement of the law, and it would have been much better for the officials there to explain what we now know: TSA officials reached their bagging policy only after extensive study, a study undertaken in part because, as the New York Times reported, “they were aware of the skepticism over the new checkpoint rules.”

“We looked at it from the chemistry point of view, the physics point of view — which kind of operational tactics one might use, with different scenarios,” said Kip Hawley. The first step was to see if the explosives intended for the London plot would actually detonate. The alleged terrorists had intended to mix the chemicals in a sealed sports drink container (Lucozade, for those interested in dumping their investment) by first removing the liquid with a hypodermic needle and replacing it with hydrogen peroxide. Another bottle would be filled with another common househld substance, which has not been named. After mixing the two together, the solution was to be detonated using a charge hidden in a hollowed out battery.

TSA scientists did not atempt to replicate these steps. Instead they allowed robots to mix the chemicals and then detonated the device while resting safely in a nearby bunker. Cameras recorded the event, and other sensors stood by to take readings on the power and duration of the blasts. After repeating the experiment using varied amounts of chemicals, they discovered that at a small enough quantity, the explosion, though deadly, would not be strong enough to destroy an airplane. “Taking into account the possibility that terrorists might act as a team and pool ingredients, officials arrived at the limit of one quart-size plastic bag per passenger,” the Times reported. TSA plans to keep the liquid-bagging procedure in place indefinitely.

-read more in Eric Lipton and Matthew Wald’s New York Times report