The first well documented intentional use of chemicals as weapons occurred in 423 b.c. when Spartans besieging Athenian cities burned pitch soaked wood and brimstone to produce sulfurous clouds.82 Chemical weapons were sporadically used, or their use considered, up through the nineteenth century.46
Large-scale chemical warfare began in World War I when the Germans released chlorine near Ypres, Belgium, killing hundreds and forcing 15,000 troops to retreat.19,46 Both sides rapidly escalated the use of toxic gases, released from cylinders or by artillery shells, including various pulmonary irritants, lacrimators, arsenicals, and cyanides.
The Germans first used sulfur mustard in 1917, again near Ypres, and caused more than 20,000 deaths or injuries.46 Unlike prior chemical weapons, mustard was persistent in the environment and vesicated the skin in addition to injuring the lungs and mucous membranes. The Allies soon responded in kind. Sulfur mustard was unequaled in its ability to incapacitate opponents.10 Injuries far outweighed fatalities, tying up manpower and resources to care for the wounded. By the end of the war, chemical weapons had caused more than 1.3 million casualties and approximately 90,000 deaths.19
Only one major chemical weapon event occurred during World War II. German planes bombed American ships carrying chemical munitions docked in the harbor of Bari, Italy, releasing the contents of 2000 mustard bombs and causing more than 600 Allied military and an unknown number of civilian casualties.10,46
Germany began producing nerve agents just before World War II. Tabun was developed in 1936 by Gerhard Schrader when conducting insecticide research for IG Farbenindustrie,29,73 but was abandoned as an insecticide because of its overwhelming human toxicity. Sarin was synthesized in 1938, and named after its developers: Schrader, Ambrose, Rudringer, and Van der Linde.29 Between 10,000 and 30,000 tons of tabun and 5 to 10 tons of sarin were produced during World War II. Soman was synthesized in 1944, but no large-scale production facilities were developed. When the Allies discovered these nerve agents at the end of the war, code names were designated based on the order of their development. Tabun was called GA (the letter G standing for German), sarin was GB, and soman was GD.29
In 1952, the British synthesized an even more potent nerve agent while searching for a dichlorodiphenyltrichloroethane (DDT) replacement. This substance was given to the United States for military development, and was named VX. A VX leak killed 6000 sheep near a military base in Skull Valley, Utah in 1968.29,41,73 The Russians developed a similar nerve agent, variably referred to as VR or “Russian VX.”37 The United States used defoliants and riot control agents in Vietnam and Laos. Iraq used sulfur mustard, tabun, and soman during its war with Iran in the 1980s, ...