Despite some protection afforded by the Chemical Weapons Convention, military chemical weapons—and chemicals that can be used as weapons—must still be assumed to be relatively available. Dedicated and trained terrorists might obtain chemical weapons from nonsignatory and noncompliant nations, or synthesize the agents themselves (Scientific American, 2001). Making chemical weapons requires some technical skill, but over time much of the information required to make these materials has drifted into the public domain. The most toxic of the common weapons—the nerve agents—can be made using relatively unsophisticated facilities and in quantities sufficient for terrorist attacks (although large-area attacks requiring tons of agents would require large-scale facilities available only to states or large corporations, not to individuals). There are a number of sources that a terrorist might use to get the information needed to make chemical weapons, including the Internet.

The Aum Shinrikyo attack on the Tokyo subway system in 1995—using sarin—proves that fabrication and use of chemical weapons by nonstate groups is now possible and can inflict significant casualties. Twelve people were killed and more than 5,000 injured in this attack (Kawana et al., 2001), and many more would have died if the terrorists had been more sophisticated in their use of the chemical agent. The deployment of chemical weapons is now more a question of the attacker’s objectives and competence than of the effectiveness or availability of the technology. In the hands of skilled terrorists, especially if they are willing to die in the effort, CW attacks could be devastating.

Industrial Chemicals

Every industrialized country is heavily reliant on chemicals. The United States is no exception; it produces, stores, and transports large quantities of toxic industrial agents. Certain of these (such as chlorine and phosgene) have actually been used as chemical weapons, as noted above; others (volatile acids, certain industrial chemical intermediates) could cause numerous casualties if released in cities in large quantities.5 Although the safety record of the chemical industry is very good, these chemicals nevertheless pose inherent risks.

Over the last 20-30 years, significant changes in the chemical and petroleum-refining industries have taken place, driven both by economic and regulatory factors; some of these changes have inadvertently helped to reduce the risks that hazardous materials might be used by terrorists. For example, the movement toward just-in-time supply of materials, while made to reduce costs, has also


A good example is the accidental release of methyl isocyanate from a chemical plant in Bhopal, India, in 1984; over 2,500 people died and more than 100,000 required medical treatment. Although a number of toxic chemicals (such as insecticides) are readily available and might be used in small-scale attacks, they are not likely to cause many casualties and are not the focus of this report.

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement