Most ways of tracking explosives impractical, task force
March 6, 1998
Taggants were analyzed as a method to detect and track
Web posted at: 10:14 a.m. EST (1514 GMT)
(CNN) -- Finding a way to reduce the risk of terrorist
bombings is proving to be an elusive goal, says a government
committee assigned to the task.
A National Research Council study released Wednesday notes
that among several possible methods of tracking explosives
considered, economic and social constraints make their
implementation nearly impossible.
"Everyone agrees that if there were an option that could
prevent terrorist bombings at low cost, it would be quickly
implemented," said Marye Anne Fox, a chemist at University of Texas at Austin and co-chairwoman of the National Research
Unfortunately, she added, the current options, in addition to
being expensive, are not effective across the board and can
invade people's privacy.( 136K/11 sec. AIFF or WAV sound)
Taggants wasteful, ineffective, study finds
The task force, made up of explosives and chemical experts,
analyzed several options to detect or track chemicals,
including the use of taggants -- tiny confetti-sized chips that can be encoded with information and planted in
explosives. They are designed to survive a bomb's blast.
The committee found problems with each possible taggant,
concluding that efforts to develop a taggant for dynamite and
other high explosives have failed to satisfy concerns about
environmental, safety and law enforcement effectiveness.
For one thing, terrorists would avoid using tagged chemicals
in making homemade bombs.
Task force members also were concerned that taggants would
turn into tons of trash each year. Billions of pounds of
explosives are used for legitimate purposes, including
mining, in the United States alone every year, said
University of Rhode Island chemist Jimmie Oxley. ( 94K/8 sec. AIFF or WAV sound)
Problems with chemical markers
Dogs sniff for chemical markers in explosives
After the bomb explosion on board Pan Am Flight 103, some authorities suggested adding chemical markers to explosives so dogs could sniff them or machines could detect them before
they were detonated.
Plastic-type explosives were used to bring down Pan Am Flight
103 over Lockerbie, Scotland, in 1988.
But the task force couldn't find a marker compatible with all
bomb components, and, as with the taggants, recommended more
|Jim Smith of the University of Rhode Island demonstrates the instability of chemicals|
1.1MB / 24 sec. / 160x120|
To make markers worthwhile, Oxley said, one would want them
to be simple and easily detectable, so that every policeman
could be issued a device to check suspicious packages for
bombs. Such devices, she added, do not exist today.( 170K/15 sec. AIFF or WAV sound)
Little success neutralizing fertilizer
Finally, the task force investigated eliminating the
explosive properties of fertilizers, including ammonium
nitrate, a common fertilizer that was used to build the bomb
that ripped apart the Oklahoma City federal building in 1995. Oxley's research team had little success in finding a way to neutralize the explosive properties.
"No practical method has yet been found that does not
seriously affect the use of ammonium nitrate as a
fertilizer," said Edward M. Arnett, a retired Duke University
chemistry professor and the committee co-chairman.
Tracking explosives purchases 'impractical'
Urea nitrate, another commonly available product, was one of
the chemicals used in the World Trade Center bombing in New York. Urea is a common de-icer and can be purchased at the
hardware store; keeping track of who has bought it would be
impractical, the study found.
The committee did recommend keeping records of who is buying
other chemicals, including ammonium nitrate and nitric acid,
another chemical used in the Trade Center bomb.
Arnett said the 18-member committee also endorsed an
international agreement to put a chemical into plastic
explosives that would make the material more easily detected
by machines at airports.
But even after the agreement goes into effect, vast amounts
of explosives will lack the identifying chemical, he said.
Science, he said, needs to develop a way to detect the
Correspondent Ann Kellan contributed to this report.