Chemical weapons in World War I
dates back thousands of years, but the first large-scale use of chemical weapons was during World War I. Austria-Hungary, France, the German Empire, the United Kingdom, and the United States used chemical weapons on the battlefield. They were primarily used to demoralize, injure, and kill entrenched defenders, against whom the indiscriminate and generally very slow-moving or static nature of gas clouds would be most effective. The types of weapons employed ranged from disabling chemicals, such as tear gas, to lethal agents like chlorine, phosgene, and mustard gas. In survivors, gas attacks caused medical problems and a strong psychological impact. This chemical warfare was a major component of the first global war and first total war of the 20th century.
Estimates go up to about 90,000 fatalities and a total of about 1.3 million casualties. However, this amounts to only 3–3.5% of overall casualties, and gas was unlike most other weapons of the period because it was possible to develop countermeasures, such as gas masks. In the later stages of the war, as the use of gas increased, its overall effectiveness diminished.
The widespread use of these agents, and wartime advances in the composition of high explosives, gave rise to an occasionally expressed view of World War I as "the chemist's war" and also the era where weapons of mass destruction were created.
The use of poison gas by all major belligerents throughout World War I constituted war crimes as its use violated the 1899 Hague Declaration Concerning Asphyxiating Gases and the 1907 Hague Convention on Land Warfare, which prohibited the use of "poison or poisoned weapons" in warfare. After the war, the 1925 Geneva Protocol was signed by all major powers, however it only prohibited state-to-state chemical warfare, not internal use or stockpiling, and Japan and the United States did not ratify it until the 1970s. Chemical weapons in World War II saw widespread use by Germany during the Holocaust and by Japan against China. However, extensive battlefield use was not seen outside China, i.e. in Europe or the Pacific, due to Western Allied stockpiles, and a stronger and transnational repugnance for poison gases following World War I.
Use of poison gas
1914: Tear gas
The most frequently used chemicals during World War I were tear-inducing irritants rather than fatal or disabling poison. During World War I, the French Army was the first to employ tear gas, using 26 mm grenades filled with ethyl bromoacetate in August 1914. The small quantities of gas delivered, roughly per cartridge, were not even detected by the Germans. The stocks were rapidly consumed and by November a new order was placed by the French military. As bromine was scarce among the Entente allies, the active ingredient was changed to chloroacetone.In October 1914, German troops fired fragmentation shells filled with a chemical irritant against British positions at Neuve Chapelle; the concentration achieved was so small that it too was barely noticed.
None of the combatants considered the use of tear gas to be in conflict with the Hague Treaty of 1899, which specifically prohibited the launching of projectiles containing asphyxiating or poisonous gas.
1915: Large-scale use and lethal gases
The first instance of large-scale use of gas as a weapon was on 31 January 1915, when Germany fired 18,000 artillery shells containing liquid xylyl bromide tear gas on Russian positions on the Rawka River, west of Warsaw during the Battle of Bolimov. Instead of vaporizing, the chemical froze and failed to have the desired effect.The first killing agent was chlorine, used by the German Army. Chlorine is a powerful irritant that can inflict damage to the eyes, nose, throat and lungs. At high concentrations and prolonged exposure it can cause death by asphyxiation. German chemical companies BASF, Hoechst and Bayer had been making chlorine as a by-product of their dye manufacturing. In cooperation with Fritz Haber of the Kaiser Wilhelm Institute for Chemistry in Berlin, they began developing methods of discharging chlorine gas against enemy trenches.
It may appear from a feldpost letter of Major Karl von Zingler that the first chlorine gas attack by German forces took place before 2 January 1915: "In other war theatres it does not go better and it has been said that our Chlorine is very effective. 140 English officers have been killed. This is a horrible weapon ...". This letter must be discounted as evidence for early German use of chlorine, however, because the date "2 January 1915" may have been hastily scribbled instead of the intended "2 January 1916," the sort of common typographical error that is often made at the beginning of a new year. The deaths of so many English officers from gas at this time would certainly have been met with outrage, but a recent, extensive study of British reactions to chemical warfare says nothing of this supposed attack. Perhaps this letter was referring to the chlorine-phosgene attack on British troops at Wieltje near Ypres, on 19 December 1915.
By 22 April 1915, the German Army had 167 tons of chlorine deployed in 5,730 cylinders from Langemark-Poelkapelle, north of Ypres. At 17:30, in a slight easterly breeze, the liquid chlorine was siphoned from the tanks, producing gas which formed a grey-green cloud that drifted across positions held by troops of the 45th Infantry Division, specifically the 1st Tirailleurs and the 2nd Zouaves from Algeria. Faced with an unfamiliar threat these troops broke ranks, abandoning their trenches and creating an gap in the Allied line. The German infantry were also wary of the gas and, lacking reinforcements, failed to exploit the break before the 1st Canadian Division and assorted French troops reformed the line in scattered, hastily prepared positions apart. The Entente governments claimed the attack was a flagrant violation of international law but Germany argued that the Hague treaty had only banned chemical shells, rather than the use of gas projectors.
In what became the Second Battle of Ypres, the Germans used gas on three more occasions; on 24 April against the 1st Canadian Division, on 2 May near Mouse Trap Farm and on 5 May against the British at Hill 60. The British Official History stated that at Hill 60, "90 men died from gas poisoning in the trenches or before they could be got to a dressing station; of the 207 brought to the nearest dressing stations, 46 died almost immediately and 12 after long suffering."
On 6 August, German troops under Field Marshal Paul von Hindenburg used chlorine gas against Russian troops defending Osowiec Fortress. Surviving defenders drove back the attack and retained the fortress. The event would later be called the Attack of the Dead Men.
Germany used chemical weapons on the Eastern Front in an attack at Rawka, west of Warsaw. The Russian Army took 9,000 casualties, with more than 1,000 fatalities. In response, the artillery branch of the Russian Army organised a commission to study the delivery of poison gas in shells.
Effectiveness and countermeasures
It quickly became evident that the men who stayed in their places suffered less than those who ran away, as any movement worsened the effects of the gas, and that those who stood up on the fire step suffered less—indeed they often escaped any serious effects—than those who lay down or sat at the bottom of a trench. Men who stood on the parapet suffered least, as the gas was denser near the ground. The worst sufferers were the wounded lying on the ground, or on stretchers, and the men who moved back with the cloud. Chlorine was less effective as a weapon than the Germans had hoped, particularly as soon as simple countermeasures were introduced. The gas produced a visible greenish cloud and strong odour, making it easy to detect. It was water-soluble, so the simple expedient of covering the mouth and nose with a damp cloth was effective at reducing the effect of the gas. It was thought to be even more effective to use urine rather than water, as it was known at the time that chlorine reacted with urea to form dichloro urea.Chlorine required a concentration of 1,000 parts per million to be fatal, destroying tissue in the lungs, likely through the formation of hypochlorous and hydrochloric acids when dissolved in the water in the lungs. Despite its limitations, chlorine was an effective psychological weapon—the sight of an oncoming cloud of the gas was a continual source of dread for the infantry.
File:The British Army on the Western Front, 1914-1918 Q8480.jpg|thumb|A gas sentry of the York and Lancaster Regiment, in his lookout position in a trench near Cambrin, 6 February 1918. Note the weather vane indicating wind direction.
Countermeasures were quickly introduced in response to the use of chlorine. The Germans issued their troops with small gauze pads filled with cotton waste, and bottles of a bicarbonate solution with which to dampen the pads. Immediately following the use of chlorine gas by the Germans, instructions were sent to British and French troops to hold wet handkerchiefs or cloths over their mouths. Simple pad respirators similar to those issued to German troops were soon proposed by Lieutenant-Colonel N. C. Ferguson, the Assistant Director Medical Services of the 28th Division. These pads were intended to be used damp, preferably dipped into a solution of bicarbonate kept in buckets for that purpose; other liquids were also used. Because such pads could not be expected to arrive at the front for several days, army divisions set about making them for themselves. Locally available muslin, flannel and gauze were used, officers were sent to Paris to buy more and local French women were employed making up rudimentary pads with string ties. Other units used lint bandages manufactured in the convent at Poperinge. Pad respirators were sent up with rations to British troops in the line as early as the evening of 24 April.
In Britain the Daily Mail newspaper encouraged women to manufacture cotton pads, and within one month a variety of pad respirators were available to British and French troops, along with motoring goggles to protect the eyes. The response was enormous and a million gas masks were produced in a day. The Mails design was useless when dry and caused suffocation when wet—the respirator was responsible for the deaths of scores of men. By 6 July 1915, the entire British army was equipped with the more effective "smoke helmet" designed by Major Cluny MacPherson, Newfoundland Regiment, which was a flannel bag with a celluloid window, which entirely covered the head. The race was then on between the introduction of new and more effective poison gases and the production of effective countermeasures, which marked gas warfare until the armistice in November 1918.