Medical Aspects of Chemical Warfare (2008) - The Black Vault

History of Chemical WarfareExhibit 2-2PhosgeneChlorine’s deficiencies were overcome with the introduction of phosgene, first used by Germany in December 1915.Phosgene, also known as carbonyl chlorine (COCl 2), is a highly toxic gas first synthesized by the chemist John Davy(1790–1868) in 1812 by exposing equal quantities of carbon monoxide and chlorine to sunlight. “Phosgene” comesfrom Greek, literally meaning “generated by light.” Phosgene is colorless and 18 times more potent than chlorine. Itis often only detected by its characteristic “moldy hay” odor. One disadvantage of phosgene as a chemical warfareagent was that it was lightweight and readily dissipated, but this problem was surmounted by addition of the heavierchlorine. The chlorine supplied the necessary vapor to help eject phosgene from containers. The British employed achlorine-phosgene mixture they codenamed “white star,” which was used heavily during the Battle of the Somme.Phosgene is a particularly insidious poison, as exposure often has no initial symptoms. Symptoms usually appearwithin 24 hours, but can take up to 72 hours to manifest. The gas combines with water in the tissues of the respiratorytract to form carbon dioxide and hydrochloric acid. The acid then dissolves the membranes in the lungs. Fluid fillsthe lungs, and death results from a combination of blood loss, shock, and respiratory failure. Phosgene was far morelethal than any other common-use gas weapon; 85% of western front soldiers were killed as the result of chemicalattack by phosgene.prevented sustained artillery barrages. 15 On the otherhand, British Commander-in-Chief Sir John Frenchacknowledged that although it failed to penetrate theGerman lines, the “gas attack met with marked success,and produced a demoralizing effect in some ofits opposing units.” 15,16,23,24Ultimately, both sides recognized the need to avoidvapors blowing backward and learned to launchFig. 2-7. “Gassed,” a purportedly staged photograph underthe direction of Major Everts Tracy, Engineer Corps, to illustratethe choking effects of phosgene. Location unknown.US Signal Corps photograph. Photograph: Courtesy of USArmy Military History Institute, Carlisle, Pa.chemicals beyond a trench line using grenades, mortarbombs, and artillery shells. These realizations ledto the introduction of the Livens projector and theStokes mortar, critical advancements to chemical warfare.Both sides also achieved satisfactory protectionagainst chlorine and began looking for newer, deadlierchemicals.PhosgenePhosgene was the next chemical to debut on thewestern front at the close of 1915 (Exhibit 2-2). The British,warned by intelligence in midsummer 1915 thatGermany planned to use a new choking gas (Figure2-7), had several months to make defensive preparations,including development of a new gas mask. Thephosgene attack took place on December 11, 1915, 9 nearthe Wieltje ruins of the Ypres salient. The British wereready for the new gas, and the Germans lost a majoropportunity to gain a decisive victory. Although gasmasks could protect troops against its harmful effects,phosgene proved to be a very effective gas throughoutthe war, causing more deaths than any other gas inWorld War I.The Germans may have used phosgene earlier, in lateMay and early June 1915, against Russian troops in thevicinity of Bzura and Rawka, and they used it extensivelyat Verdun in 1916. 15 The “white star” mixture ofphosgene and chlorine (chlorine supplied the necessaryvapor to carry phosgene) was commonly used on theSomme. When newer gas masks gave adequate protectionagainst chlorine and phosgene, both sides realizedthat the vapor clouds were better suited as psychological19