WASHINGTON, Aug. 14 (UPI) -- Experts and officials are warning that the ban on carrying liquids and gels on airliners is likely to continue for some time, even though the immediate threat from the foiled London plot to attack transatlantic flights appeared to have mainly passed.
Homeland Security Secretary Michael Chertoff said Sunday that he did not anticipate a total ban on hand-luggage, such as that imposed by the British, being necessary on U.S. flights "at this point." But he suggested that the ban on liquids, gels and aerosols -- which was amended slightly by the Transportation Security Administration Sunday -- would remain in place for the time being.
"We think that with the measures we have regarding liquids, with the training we've given the screeners and with the tools we have, we're capable of protecting the airlines," he told ABC News.
The changes to the ban announced Sunday basically expanded the exemptions from the ban, so that they include essential non-prescription medications and non-medical material for diabetics, like glucose gel.
"This is a whole new era of threats to aviation," Rep. John Mica, R-Fla., chairman of the House of Representatives aviation subcommittee, told United Press International.
He said that even once the London plotters had all been apprehended, the threat would persist from the kind of "non-traditional explosives and component bombs" they had allegedly planned to smuggle onto U.S.-board airliners disguised as a sports drink and set off with a detonator hidden in an electronic gadget.
Mica said the threat from liquid explosives had been known about for some time. "It's not something we weren't anticipating," he said.
Penny Dodge, spokeswoman for Rep. Peter DeFazio, D-Ore., who was for many years the ranking Democrat on Mica's subcommittee, confirmed that both congressmen had warned authorities about the dangers of liquid explosives as long ago as 2001.
Some commentators seized on this to criticize the Department of Homeland Security for not acting sooner.
"The most frightening thing about the foiled plot," read an editorial in Saturday's New York Times, "is that both the government and the aviation industry have been aware of the liquid bomb threat for years, but have done little to prepare for it."
But Chertoff said that, until very recently, officials had remained confident of their ability to detect so-called component bombs using liquid explosives by traditional screening using X-ray and other imaging technology to look for giveaway metallic components.
He said it was the details of the London plot that changed minds.
"It was the sophisticated nature of the disguised bombs, I think, that caused us to" change the rules, he told CNN.
"In the past, when we've looked at and analyzed these kinds of bombs, they have been in a form that our screeners are capable of recognizing. We've particularly focused on the detonators. In this case, without getting too specific about the details, it appeared to us, at least initially, that the disguise method might be so sophisticated that we might need to change the training for the screeners and take some additional measures."
He added that the alternative approach -- to screen for explosive chemicals themselves -- was also fraught with challenges
"The difficulty is, what do we do with explosives made out of very common chemicals, chemicals that almost everybody has with them in their dry cleaning or their cosmetics? Because we don't want a system that has so many false positives that we have hours and hours waiting on line at the airport because we have to open every bottle and every cosmetics case."
"The challenge," he concluded, was "finding a technology that will fit with our system and not create delays and impediments for the air traveler."
Experts said that in the absence of any reliable way to routinely screen hand baggage for explosive chemicals there was little option but to retain the ban on liquids and gels.
"Short of any other good counter-measure, the logical measure is for the ban to last for some time," Richard Jackson, a principal with the homeland security consultants the Civitas Group, told UPI.
He said the problem with existing technology is that "liquids are generally low density and don't image very well."
He added there were "plenty of inert liquids that could be turned into bombs."
Cathleen Berrick, director of the Government Accountability Office's homeland security and justice division, told UPI that the equipment used at passenger screening checkpoints was key. "We can't improve until we strengthen the technology," she said.
Matthew Farr, senior homeland security advisor with stock analysts Frost & Sullivan, told UPI that, since Sept. 11, the continuing focus on screening for metal objects was the equivalent of fighting the last war.
"We're still in the mindset of trying to protect against metallic objects," he said, adding that "the solutions are here today. Someone just has to buy them."
But Deputy Homeland Security Secretary Michael Jackson told reporters in a conference call last week that the department had done "some testing on machines that screen for liquid (explosives)," but added that, "There's nothing ready for mass deployment yet."
Farr hoped that the continuing ban, and the consequent inconvenience for passengers, would have the positive effect of spurring demands for a new generation of screening technology.
"I hope that the measures they've put in place will stay in place or they'll become more strict with carry-on items," Farr said. "It's the only way (passengers will) demand more change."
