TABLE 4.1 Approximate Toxicitya of Selected Chemical Agents

Type

Agentb

LCt50c

ICt50c

Choking

Phosgene

3,200

1,600

Blistering

Mustard (HD)

900

450

Blood

Hydrogen cyanide

2,000 to 4,500

Variesd

Nerve

Tabun (GA)

270

200

Sarin (GB)

35

20

Soman (GS)

70

35

VX

15

8

aFor respiratory exposure to vapor or aerosol; other forms of exposure are also possible (e.g., skin exposure or ingestion).

bAbbreviations in parentheses are common military designations.

cDosages expressed as concentration × time (Ct) in units of mg-min/m3. LCt50 refers to a dosage that is lethal to 50 percent of the exposed population; ICt50 refers to a dosage that is incapacitating to 50 percent.

dThe incapacitating dosage depends on the concentration.

SOURCE: NRC (1999), p. 69.

damaging logistics systems, and attacking the cities of adversaries. Large portions of the Soviet technology are now presumed to be widely available to other countries and to an unknown but probably growing number of nonstate groups.3,4

The Chemical Weapons Convention, ratified by more than 160 nations (including the United States) in 1997, has the objective of eliminating chemical weapons from state production, storage, and use. It was not specifically designed to reduce terrorist activities. However, it is likely to have some impact because it reduces the availability of CW, as they are destroyed under the observation of the Organization for the Prohibition of Chemical Weapons (OPCW). In addition, certain chemicals and equipment that could be used to produce CW must be routinely reported, and facilities producing them must be inspected. These requirements present a terrorist with obstacles to producing and concealing the production of CW. Further, nations that are members of the OPCW are prohibited from trading with nonsignatory nations—which currently include Iraq, Libya, North Korea, and Syria, among others—in certain chemicals used as precursors.

3  

At least one Middle Eastern country hostile to the United States—that is, Iraq—possesses and has used chemical weapons in military operations and against its own people.

4  

The technology of designed chemical weapons has been relatively static for a decade (since the collapse of the Soviet effort). There is, however, the potential for development of new classes of chemical weapons. The Soviet Union experimented extensively with a variety of agents, and the results could provide starting points for new programs. Some of these could be developed rapidly if significant financial resources and technical expertise were applied.



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