Chap. 13. Terrorism, Toxicity, and Vulnerability 329only about 10 seconds. The precipitating event was not terrorism — although it well
could have been — and probably resulted from nothing more dramatic than tree limbs
interfering with transmission lines.
The electrical power failure described above illustrates a phenomenon called
cascading failures on complex networks.^2 An electrical power distribution system is
a complex network of hundreds of electrical power plants interconnected by electrical
transmission lines. Such a system enables very efficient generation, distribution, and
utilization of electrical power in that a surge in demand on one part of the system can
be compensated by redistribution of power from the network to that segment of the
system. Therefore, local generating facilities do not have to have the capacity to meet
temporary demand, resulting in high efficiency and much lower costs. Other parts of
the infrastructure have similar networks. Routers on the Internet are designed to route
Internet traffic around bottlenecks or other routers that are temporarily out of commission.
Modern manufacturing operations using “just-in-time” deliveries of components make
it unnecessary to stockpile large quantities of parts, thereby minimizing the need for
production capacity and maximizing efficiency. The downside is that these systems
operate “close to the edge” so that a relatively small failure, such as one brought about
by human mischief, can rapidly cascade into a major failure.
Chemistry can be applied to infrastructure protection. One area in which this is
true is the production of materials that resist heat and flame. Such materials used in
buildings can provide substantial protection from fire. Processes that are consistent with
the practice of green chemistry also provide protection from attack. For example, green
chemistry attempts to reduce the production and use of hazardous materials. Sophisticated
analytical chemistry and analytical instrumentation can be used to detect agents of attack
before damage is done.
13.3. Substances That Explode, Burn, or React Violently
Substances that react violently and rapidly enough to cause fires, explosions, or
corrosive destruction of materials are those that have been used most commonly in
terrorist attacks and that have the most potential for future use. Reactive substances,
such as explosives used to quarry rock, have many commercial uses and are therefore
widespread and potentially readily available, both to legitimate users and terrorists.^3
Explosives are the most common materials used in terrorist attacks. The devastating
effects of explosives have been illustrated by a number of incidents including the 1995
bombing of the Murrah Federal Building in Oklahoma City, the 2003 bombing of the
British consulate in Turkey, and frequent bombings of various sites in Iraq in 200–06.
Explosives can be made from readily available materials; the Murrah Federal Building was
brought down by a mixture of ammonium nitrate fertilizer and diesel fuel. Gunpowder has
long been prepared from charcoal, sulfur, and nitrate salts. Nitroglycerin, the explosive in
dynamite, is made from glycerin, a byproduct of soap preparation, reacted with nitric and
sulfuric acids (most amateurs who attempt this synthesis succeed in blowing their heads
off). More sophisticated explosives consist of organic compounds containing nitrogen
and oxygen, such as 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane