Pocket-Size Reactors May Raise Chemical Terrorism Risk

Brian Handwerk
for National Geographic News
August 11, 2005
Chemical reactors are shrinking to notebook and even credit card size. The technology offers a safer way to produce some toxic materials—but it could be deadly in the wrong hands, experts warn.

"Micro-reactors" convert chemicals—for example a fuel cell micro-reactor may be able to turn methanol into hydrogen to power a car—in much the same way a building-size chemical recator does, only on a smaller scale.

The tiny reactors are not easily obtainable, and the chemicals used in them can be highly unstable. As a result, experts say, they aren't the most practical or efficient weapon choices for terrorist groups—at least for now.

But the miniature systems have already been used to produce potentially lethal but useful chemicals such as hydrogen cyanide, phosgene, and methyl isocyanate.

China's Xi'an Huian Chemical company, in partnership with Germany's Institute for Microtechnology Mainz (IMM), has used "micro-process" technology to create nitroglycerine, a toxic and highly explosive chemical, for medical uses.

Using a micro-reactor, Xi'an Huian Chemical and IMM "were able to synthesize [nitroglycerine] at a rate of 10 kilograms [22 pounds] an hour. So you can imagine that there's an ability to produce a lot of material," said Tuan Nguyen of the Center for Global Security Research, a division of the U.S. government's Lawrence Livermore National Laboratory in California.

Nguyen addresses the potential dangers of miniaturized chemical weapons in tomorrow's edition of the journal Science.

"You can conceive that you wouldn't need very much phosgene gas [a severe respiratory irritant that has been used in chemical warfare] to disrupt a subway car in Manhattan," said Ronald Besser, professor of chemical engineering at Stevens Institute of Technology's New Jersey Center for MicroChemical Systems (NJCMS).

"A very small reactor that could be transported in a briefcase might be able to produce enough of a highly toxic material to injure a lot of people," he said. "That concept is a possibility that I think needs to be dealt with."

A Safer Way to Make Hazardous Materials

Micro-reactor technology is still in its infancy, but the technology offers a suite of valuable benefits. The ultraefficient systems offer a safer working environment for hazardous materials.

"Everything is in small quantities and in a small reactor, so that, even if you do have some kind of leak, it can be contained," NJCMS's Besser explained. "It's a safer way to work with toxic chemicals."

The technology also makes possible just-in-time production, allowing engineers to produce toxic chemicals when and where they require them.

Besser points to phosgene, a nerve agent that was used as a chemical weapon in World War II and is important to the production of plastics. "Why not just make it at the moment you need it, right at the reactor where you are making plastic, rather than making and storing large quantities of a toxic material?"

Although micro-reactors produce only small quantities of a given chemical, they can be linked together to produce larger volumes. This flexibility, along with the micro-reactors' efficiency, also makes them economically attractive.

A Pandora's Box?

At present micro-reactor technology is relatively inaccessible to people outside the field. But as training and production become more widespread, the danger could increase.

"There are some complicated systems, but there are also very simple reactors that wouldn't require too much sophistication," Nguyen, the study author, said. "So in terms of who might be able [to produce dangerous chemicals with such systems], we really can't say."

"It's still an emerging technology, so as of today it probably wouldn't be available to terrorist groups," NJCMS's Besser said. "But 20 years ago you couldn't run out and buy a cell phone for 20 bucks and use it to detonate a roadside bomb. It's all about technology becoming cheaper and more available."

The rapidly developing field poses special challenges for agencies that enforce agreements like the international Chemical Weapons Convention.

"This is a new technology to make chemicals, so the [signs] we've always looked at [to track] chemical production will be different," Nguyen said. "Now instead of looking for large batches, you might be looking at small reactors. This is an example of a technology that will make compliance verification more difficult and also make it more difficult to tell what these reactors are being used for."

Attractive Option for Terrorists?

Many toxic gasses are unstable or tend to break down quickly, and dispersing chemicals for a maximum terror impact is difficult.

"Chemical weapons on the whole are generally not something that terrorists employ, for a number of reasons," said Michael Stebbins, director of biology policy at the Federation of American Scientists in Washington, D.C. "That's not to say that they won't, or that they aren't planning to.

"But generally these weapons are less effective to employ, because they are often technically difficult to make and very dangerous to work with, not to mention distribute, in an attack."

Stebbins cites the example of the 1995 sarin-gas attack in the Tokyo subway by members of the Aum Shinrikyo cult. "Pound for pound, in the same package, they would have hurt a lot more people with dynamite than with sarin."

Stebbins doubts that terrorist groups, at least at present, can take advantage of emerging micro-reactor technologies.

"It's not an easy thing to do, and it's extremely dangerous," he said. "You have to have access to the technology, access to the raw materials, and you also need advanced expertise to deal with this kind of technology. All these are factors that go into making it very difficult to make these things."

But Nguyen, the study author, hopes to focus international attention on the rapidly spreading technology to head off trouble before it begins.

"The first step is to get the policy and science communities together to have a better understanding of the technology," he said. "Looking at these science and technology advancements at an early stage allows us to better deal with problems before they arise."

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