An End To Anonymous Bombs?

Even the NRA may not be able to stop IDs for explosives

Tagging explosives with minute chemical markers to help the FBI track down terrorists ought to have surefire voter appeal. In the aftermath of the fiery crash of TWA Flight 800 and the bombing in Atlanta's Centennial Olympic Park, a proposal to require such "taggants" is once again at the center of Washington debate.

Requiring explosives makers to mix in the telltale markers might seem innocuous enough, but over the past 20 years such proposals have been regularly carted up to Capitol Hill and just as regularly rejected--most recently last year, when Congress shot down such a proposal. Instead, it authorized a study of their effectiveness--and then refused to fund it. Legislators retreated in the face of vehement opposition from the National Rifle Assn. and explosives makers, who claim that taggants are costly and potentially deadly.

RAINBOW CODE. It's all a smoke screen, retorts Charles W. Faulkner, general counsel at Microtrace Inc. in Blaine, Minn., the oldest supplier of tags. "All these rumors have been floating around for years," he says. "What they conveniently ignore is that we've been supplying Microtags to Switzerland for 13 years, with no safety problems." Switzerland mandates the tagging of all explosives made within its borders.

Faulkner admits opponents are right when they project costs of hundreds of millions of dollars for explosives makers. But he prefers to put the costs in a different light. On a per-pound basis, he says, taggants "would be 2 cents or less."

The tags that Microtrace sells were invented in the early 1970s by Richard G. Livesay, a chemist at 3M. They are tiny plastic chips no bigger than a grain of pepper. The chips have 10 layers, each a different color, that can be stacked in millions of combinations. So a distinctive rainbow code can identify each manufacturer, batch of explosives, and its distributor.

From 1977 to 1979, a federal test of 3M's technology put taggants in 1% of all explosives made. When a truck blew up in Baltimore in May, 1979, killing Robert J. Riffe, tags found in the wreckage quickly led federal agents to James L. McFillin. He was convicted that December. In Switzerland, the tags have helped solve 566 bombings over a decade, according to the Office of Technology Assessment (OTA).

However, things started to go sour for 3M in July, 1979. A blast at the Goex Inc. explosives plant in Camden Park, Ark., was blamed on the taggants. Goex sued. 3M was exonerated, but opponents of tagging still cite the incident as a danger signal. The following year, Congress called a halt to the test under pressure from critics. 3M later sold the technology to Livesay, who founded Microtrace. Today, says Faulkner, the tags are used mainly as anticounterfeiting markers for consumer goods, including shampoo and alcohol, as well as for replacement parts for planes and trucks.

Now, a newer tagging technology is being marketed by Isotag LLC in Houston. And it could undermine a crucial point of opposition: that no practical method exists for tagging ammonium nitrate, which was used in the bomb that devastated the federal building in Oklahoma City in 1995.

Isotag's chemical markers are very rare, heavyweight molecules that can be detected in extremely low concentrations--one taggant molecule among millions of product molecules. They are now used mainly to identify natural gas and petroleum products flowing through pipelines.

In 1993, a fertilizer company wondered if Isotag's markers could survive an ammonium nitrate explosion. Tests showed they could. "Tagging with the old technology costs $65 to $100 per ton" of liquid, says Isotag President D. King Anderson. But with Isotag's markers, he figures the cost would be about $7 a ton.

Perhaps the most effective opposition to taggants has come from the NRA, which argues that their use in gunpowder would raise serious safety issues for its 3 million members. For example, if the ratio of tags to gunpowder varies, so would the explosive punch of bullets. "Some rounds might be so powerful they could blow up in the gun," says NRA spokesman Chip Walker. The organization is not opposed to tagging high explosives, like dynamite and plastic, or agricultural chemicals, such as ammonium nitrate.

DOMINO EFFECT? However, the U.S. companies that produce 4 billion pounds of explosives have their own worries. The Institute of Makers of Explosives (IME), a Washington lobbying group, figures that tags would increase costs by $750 million a year in the mining industry alone. As for safety, the IME points to a 1980 study by the OTA that found signs that taggants reduce the stability of explosives. Jimmie Oxley, a professor of chemistry at the University of Rhode Island, recently analyzed some tagged TNT and says she was "surprised to find out that it changed the thermal properties of the TNT." This change could make TNT more dangerous to work with.

The availability of a practical way to tag ammonium nitrate, combined with the political demands for new antiterrorism legislation, could mean that explosives tagging now has a chance of becoming law. Walker says the NRA would accept tagging if an independent, scientific study determined it is safe.

If tagging were required in the U.S., some 90-odd other countries might shift gears and speedily follow suit, tightening the worldwide supply of bomb-grade explosives. At a meeting of the International Civil Aviation Organization in 1991, 2 1/2 years after the bombing of Pan Am Flight 103 over Lockerbie, Scotland, half of the ICAO members signed a treaty "in principle" to require the tagging of explosives. But five years later, only 22 countries have ratified the treaty. For it to take effect, 35 are required.

Representative Charles E. Schumer (D-N.Y.) believes that tagging now stands a real chance. "But unless Congress stands up to the NRA, it is going to be extremely difficult to get this important legislation done," he says. The U.S. has been playing with tagging long enough. Congress may finally be ready to take a stand.