The Star-Ledger August 11, 2006
An explosive that's easy to build -- and hard to detect
By Kevin Coughlin and Ron Marsico
An explosive "bathtub brew," concocted from nail polish, drain cleaners and antiseptics, may have been behind yesterday's chaos at airports across the United States and around the globe.
Security officials at Newark Liberty International Airport were warned Wednesday night that suspects arrested in England had been poised to bomb U.S.-bound planes with a liquid- or gel-based form of the explosive TATP -- which screening devices and even bomb-sniffing dogs might not detect.
The arrests prompted authorities on both sides of the Atlantic to bar passengers from boarding flights with liquids, gels, even toothpaste.
Besides delaying millions of travelers, this latest round in the cat-and-mouse game with terrorists underscored what experts say is aviation security's weak link: Billions spent to protect planes since 9/11 still cannot guarantee that bombs won't slip through airport checkpoints.
"We can't stop it if it's covered. We've got to see it," said an airport security official, speaking on condition of anonymity.
The "it," according to three security officials familiar with the situation, is likely TATP.
Palestinian bomb-makers have another name for TATP, or triacetone triperoxide: "Mother of Satan." Made from items found in supermarkets, the colorless, odorless solution is highly unstable.
"TATP is one of the most sensitive explosives known, being extremely sensitive to impact, temperature change and friction," according to GlobalSecurity.org.
Thwarted "shoe bomber" Richard Reid used TATP as a detonator in 2001. It's also suspected in last year's London subway bombings, and in a 1994 bombing that killed one passenger on a Philippine Airlines flight.
British authorities arrested 24 people across England yesterday, foiling what officials described as a plot to simultaneously down 10 jetliners headed for the United States. The suicide strike may have been just days away.
TERROR'S TRADEMARKS
The scheme -- which resembles past al Qaeda operations -- called for in-flight assembly of a peroxide-based compound and its detonation by electricity from a camera, digital music player or other electronic device, the Associated Press reported.
British authorities banned laptop computers, cell phones and iPods, as well as liquids, from planes yesterday. The explosives would have been disguised as beverages and other everyday items, U.S. Homeland Security Secretary Michael Chertoff said.
Chertoff's agency has been criticized as being slow to install equipment at airports that might detect liquid explosives.
"The need to address this liquid explosives problem is over 10 years old," U.S. Rep. Ed Markey (D-Mass.) said in a statement yesterday.
Experts said X-ray machines and equipment that analyzes swabs from luggage for traces of nitrate-based explosives cannot see TATP.
INVISIBLE WEAPON
"It's very easy to conceal," said Robert Statica, who heads a new counter-terrorism program at the New Jersey Institute of Technology in Newark.
"Bomb-sniffing dogs may be unable to detect it," said former FBI agent Stephen Foster, now an NJIT instructor. "Scanning technologies won't see any more than it's a container containing a liquid."
A thwarted Philippines plot to blow up jetliners over the Pacific in 1995 involved plans to disguise nitroglycerin as contact lens solution, and detonate it using digital watches as timers. An explosion in a Manila apartment tipped off investigators. That scheme was hatched by Ramzi Youssef, now serving a life sentence for the first World Trade Center attack.
Two techniques that may detect liquid explosives are mass spectroscopy and liquid or gas chromatography. Devices capable of performing both tests cost between $20,000 and $40,000, said Dan Watts, an organic chemist who runs the Center for Environmental Engineering and Science at NJIT.
Mass spectroscopy identifies compounds based on their molecular weight. Because many benign compounds have weights similar to explosives, this technique might spur authorities to perform further tests.
That's where chromatography would come in. An unknown compound is timed as it passes through a column lined with absorbent materials. Different compounds move through at different rates.
To identify liquid explosives with certainty using this method, authorities would need to know the specific rates for these explosives, Watts said.
Compiling a library of these signatures could take quite a while, Watts said. And wide deployment of these methods could mean even longer delays at airports, he said, because these tests can take 20 minutes to complete.
'LOGICAL RESPONSE'
"Is this overkill to ban everything? Perhaps. But it's a very logical response" under the circumstances, Watts said.
TATP usually is a solid. But with care, it can be suspended in a gel or in water, Watts said. The emphasis is on care. Although the ingredients are common -- acetone, hydrogen peroxide , hydrochloric acid -- the results are highly unpredictable.
"The potential for self-harm is really high. Nobody should take their chemistry set and try to do this at home," Watts said.
NJIT is working with a Michigan company, Picometrix, on terahertz imaging, a screening method similar to X-rays. The technology should detect liquid explosives -- but it's a few years away, said David Zimdars, a Picometrix research manager.
But technology alone won't protect the skies, said retired Bell Labs chemist Frank Stillinger, who has taken part in two federal studies related to bomb detection for aviation.
"I don't think there's a universal solution. That is the basis of terrorist threats. They're always looking for new, unsuspected scenarios," Stillinger said. "We have to respond to the extent that we can."
The Associated Press contributed to this report.
© Copyright 2006, The Star Ledger
