Chlorine Gas
At 5 PM on 22 April 1915, German troops at Ypres discharged 180,000 kg of chlorine gas from 5,730 cylinders on the line between Steenstraat on the Yser Canal, through Bixschoote and Langemark, to Poelcappelle. The gas cloud blew with the wind, and either killed or caused the French and Algerian troops in the opposing trenches to flee, opening an 8 to 9 km gap in the Allied line. On 24 April 1915, the Germans conducted a second chlorine gas attack at Ypres, this time against Canadian troops.
On 31 May 1915, chlorine was first employed on the eastern front, by the Germans at Bolimow, near Skierniewice, 50 km southeast of Warsaw. This attack employed 12,000 cylinders, releasing 264 tons of chlorine along a 12 km line. There were nearly 200 chemical attacks during World War I using gas released from cylinders; the largest of these occurred in October 1915 when the Germans released 550 tons of chlorine from 25,000 cylinders at Rhiems.
Prof. Fritz Haber was chief of the German chemical warfare service during World War I and personally directed the first chlorine gas attack. Haber, a Nobel laureate and known for his discovery of a process for synthesizing ammonia by the combination of nitrogen and hydrogen, is often referred to as the father of chemical warfare.
The Antecedents of Chemical Warfare
Many chronicles of the history of chemical warfare begin with "At 5 PM on 22 April 1915...." What is perhaps less appreciated is that the first chlorine attack represented merely an escalation of an existing use of irritant chemicals. The use of irritating smokes, e.g., from burning sulfur, against enemy fortifications dates to antiquity. The vagaries of wind and weather and the lack of modern chemical technology had served as an effective limitation to the employment of chemicals in warfare prior to 1914.
In fact, several belligerents in World War I had been using munitions filled with irritants from almost the beginning of hostilities. The French first used shells filled with ethyl bromoacetate in August 1914, less than one month into the war, and chloroacetone was introduced into the French arsenal in November 1914. On 27 October 1914, the Germans at Neuve-Chappelle used the "Ni-Schrapnell" 105 mm shell, which consisted of lead balls embedded in powdered o-dianisidine chlorosulfonate. On 31 January 1915 at Boloimow, the Germans introduced 150 mm shells filled with "T-Stoff," a mixture of brominated aromatics including xylyl bromide, xylylene bromide, and benzyl bromide. All these compounds are extreme irritants capable of severely limiting the effectiveness of unprotected troops.
Development of Additional Agents
As the war continued, many toxic compounds in addition to chlorine were tested for utility as chemical warfare agents:
- Bromine
- Trichloromethylsulfuryl chloride
- Phosgene ( CG). On 19 December 1915, 88 tons of phosgene were released from 4,000 cylinders at Nieltje in Flanders
- Trichloromethyl chloroformate ( DP, diphosgene)
- Monochloromethyl chloroformate
- Hydrogen cyanide ( AC)
- Hydrogen sulfide
- Trichloronitromethane ( PS, chloropicrin)
- Cyanogen bromide
- Cyanogen chloride ( CK)
- Phenylcarbamine dichloride (phosgene anilide)
- Dichloromethyl ether
- Dibromomethyl ether
- Methyl cyanoformate
- Ethyl cyanoformate
- Methanesulfonyl chloride
- Ethanesulfonyl chloride
- Ethyldichloroarsine
- Methyldichloroarsine
- Ethyldibromoarsine
- Bischloroethyl sulfide (HS, mustard gas) First used in an artillery attack on 12 July 1917 by the Germans. This agent caused the most casualties of any agent used during World War I.
Of those chemical warfare agents tried, chlorine, phosgene, diphosgene, chloropicrin, hydrogen cyanide, cyanogen chloride, and mustard were produced and used in large quantities.
Production of Chemical Warfare Agents during WWI (in tons) 3 , 4
|
|
Chlorine |
Phosgene |
Diphosgene |
Mustard |
Chloropicrin |
Cyanides |
Total |
| Germany |
58,100 |
18,100 |
11,600 |
7,600 |
4,100 |
|
99,500 |
| France |
12,500 |
15,700 |
|
2,000 |
500 |
7,700 |
38,400 |
| Britain |
20,800 |
1,400 |
|
500 |
8,000 |
400 |
31,100 |
| US |
2,400 |
1,400 |
|
900 |
2,500 |
|
7,200 |
| Austria |
NA |
NA |
NA |
0 |
NA |
NA |
5,245 |
| Italy |
NA |
NA |
NA |
0 |
NA |
NA |
4,100 |
| Russia |
NA |
NA |
NA |
0 |
NA |
NA |
3,650 |
|
Total |
93,800 |
36,600 |
11,600 |
11,000 |
15,100 |
8,100 |
189,195 |
Note that a portion of the chlorine, phosgene, and cyanide were used for non-chemical warfare purposes. A total of 150,000 tons of chemicals were produced for chemical warfare purposes, and 125,000 tons of that were actually used on the battlefield. 4
Development of Additional Means of Delivery
At the same time as they experimented with more lethal chemical agents, both sides worked to develop more effective methods of agent delivery. Gas cloud attacks relied on the wind; in the absence of wind or if the wind blew from the wrong direction, gas cylinders were useless. If the wind shifted shortly after a release, the gas would blow back onto the attacking forces. Thus, a number of new means of delivering chemical warfare agents to the opposing forces were introduced:
- The 4 inch Stokes mortar developed for chemical agent delivery, first fielded in September 1915 at Loos; this represented the first use of projectiles filled with lethal chemicals in World War I.
- The Germans produced chemical agent-filled projectiles for 77 mm., 105 mm, and 150 mm artillery pieces, and the French produced agent projectiles for their 75 mm rapid firing gun.
- The British Livens Projector was a large-scale mortar developed for delivering large amounts of chemical warfare agent.
The Toll of Chemical Warfare, 1914-1918
It is difficult to find a definitive figure for the numbers of men injured and killed by chemical warfare agents during World War I. British casualties alone can be estimated at 185,000 injured and 8,700 dead. 5 Prentiss gives a figure of 1,296,853 casualties produced by approximately 125,000 tons of chemical warfare agents used by the combatants, 4 but it is known that in many cases the official figures underestimate the number of casualties. Furthermore, it is unclear to what degree the official figures include individuals who were injured in gas attacks but who developed serious symptoms only after the war. Given Prentiss' estimate of 10,000,000 battle deaths from the war, it is arguable as to whether chemical warfare was more or less horrific than the other methods of conducting the war.
References
The historical information on this page comes primarily from the references listed below.
1. Paxman, J.; Harris, R., A Higher Form of Killing : The Secret Story of Chemical and Biological Warfare, Hill and Wang, New York:1982, pp. 24, 32.
2. Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare. A Study of the Historical Technical, Military, Legal, and Political Aspects of CBW and Possible Disarmament Measures. Vol. 1. The Rise of CB Weapons, Humanities Press: New York, 1971, pp. 27-34, 42, 131-132.
3. Haber, L. F., The Poisonous Cloud. Chemical Warfare in the First World War, Clarendon Press: Oxford, 1986, p. 170
4. Prentiss, A. M., Chemicals in War. A Treatise on Chemical Warfare, McGraw Hill: New York, 1937, pp. 661-666.
5. Reference 2, p. 130.