CNN logo
Message Boards 

CNN Networks 

Quick News 
Video Vault 
News Quiz 

Pathfinder/Warner Bros

Barnes and Noble

Tech banner

An expanded Web version of segments seen on CNN

Most ways of tracking explosives impractical, task force finds

Taggants were analyzed as a method to detect and track chemicals   
March 6, 1998
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 Council study.

Unfortunately, she added, the current options, in addition to being expensive, are not effective across the board and can invade people's privacy.(icon 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.

CNN's Ann Kellan reports
icon 2 min. 15 sec. VXtreme video

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. (icon 94K/8 sec. AIFF or WAV sound)

Problems with chemical markers

Dogs sniffing
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 study.

Jim Smith of the University of Rhode Island demonstrates the instability of chemicals
video icon 1.1MB / 24 sec. / 160x120
QuickTime movie

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.(icon 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 explosive itself.

Correspondent Ann Kellan contributed to this report.

Special Sections:

Related stories:

Related sites:

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.

Infoseek search  

Message Boards Sound off on our
message boards & chat

Back to the top

© 1998 Cable News Network, Inc.
A Time Warner Company
All Rights Reserved.

Terms under which this service is provided to you.
Read our privacy guidelines.