Gas Attacks and Their Medical Treatment: Chlorine, Phosgene and Mustard Gas
Poison gas was introduced as a weapon on the Western Front from 1915 and created wound types the British medical services had never had to treat before. Chlorine gas was used by the Germans in a large-scale attack near Ypres in April 1915; it damaged the lungs and caused choking, and its greenish-yellow colour meant it could at least be seen coming, so soldiers improvised early protection such as cloth pads soaked in urine, since the ammonia in urine helped neutralise the chlorine. Phosgene, introduced later in 1915, was far deadlier because it was colourless and less immediately irritating than chlorine, so soldiers could inhale a dangerous dose before realising, and its worst effects on the lungs were often delayed by up to 48 hours. Mustard gas, introduced by the Germans in 1917, was a blistering agent that caused severe burns to the skin, eyes and lungs and could persist in the ground for days, and because standard respirators like the box respirator protected the lungs but not exposed skin, it produced huge numbers of casualties, though it killed a smaller proportion of those it affected than phosgene did.
Before you start
Make sure you're comfortable with these topics first:
Method
- Learn the three gases in the order they were introduced, since 'explain the development of X' questions reward showing change over time: chlorine (1915), phosgene (later in 1915) and mustard gas (1917).
- Learn chlorine's effect and its one practical weakness for the attacker: it damaged the lungs and caused choking, but its visible greenish-yellow colour gave soldiers some warning, and improvised protection such as a urine-soaked cloth pad could partly neutralise it.
- Learn why phosgene was deadlier than chlorine despite arriving second: being colourless and less immediately irritating meant soldiers could breathe in a dangerous dose without realising, and its worst lung damage was often delayed by up to 48 hours, so phosgene caused the majority of British gas deaths in the war.
- Learn mustard gas's distinct mechanism: unlike chlorine and phosgene, which attacked the lungs when inhaled, mustard gas was a blistering agent that burned any skin, eyes or lungs it touched, and it could linger in soil and mud for days after an attack.
- Learn why mustard gas produced huge casualty numbers but a lower death rate than phosgene: standard respirators such as the box respirator filtered the air soldiers breathed but left skin exposed, so many men were badly burned or blinded rather than killed.
- For treatment questions, separate immediate battlefield response (respirators, and getting casualties away from the gas as fast as possible) from later medical treatment at dressing stations and hospitals (treating burns, easing breathing, and, for mustard gas, decontaminating skin and clothing).
Worked example
Explain why phosgene gas caused more deaths on the Western Front than chlorine gas.
- State chlorine's key weakness as a weapon: its greenish-yellow colour and strong smell gave soldiers some warning, allowing at least improvised protection to be used in time.
- State phosgene's key advantage as a weapon: it was colourless and far less immediately irritating than chlorine.
- Explain the consequence of this: soldiers could inhale a dangerous concentration of phosgene without realising they had been exposed until it was too late to protect themselves fully.
- Add the delayed-effect detail: phosgene's most serious damage to the lungs often did not appear for up to 48 hours after exposure, so its full danger was not always obvious at the time.
- State the overall answer: because phosgene was harder to detect and its effects were delayed, it caused proportionally more deaths than chlorine, which is why it is linked to the majority of British gas deaths during the war.
Practice questions
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Q1In which year, and near which town, did the Germans first use chlorine gas in a large-scale attack on the Western Front?Show answer
Answer: 1915, near Ypres.
Q2Why could chlorine gas at least be partly guarded against?Show answer
Answer: Its greenish-yellow colour made it visible, giving some warning, and improvised protection such as a urine-soaked cloth pad could help neutralise it.
Q3Why was phosgene more dangerous than chlorine, despite being introduced afterwards?Show answer
Answer: It was colourless and much less immediately irritating, so soldiers could inhale a dangerous dose before realising, and its worst effects on the lungs were often delayed by up to 48 hours.
Q4In what way did mustard gas, introduced in 1917, work differently from chlorine and phosgene?Show answer
Answer: It was a blistering agent that burned any exposed skin, eyes or lungs it touched, rather than only damaging the lungs when inhaled, and it could persist in the ground for days.
Q5Why did mustard gas cause huge numbers of casualties but comparatively fewer deaths than phosgene?Show answer
Answer: Standard respirators filtered the air soldiers breathed but did not protect exposed skin, so mustard gas badly burned or blinded many men without necessarily killing them.
Q6Name one type of respirator issued to British troops as protection against gas attacks.Show answer
Answer: The box respirator (or an earlier improvised protection such as a urine-soaked cloth pad against chlorine).
Exam-style questions
Written in the style of a GCSE History exam paper, with a full mark scheme.
Describe two features of mustard gas as a weapon used on the Western Front.
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How useful are Sources A and B for an enquiry into the medical impact of gas attacks on the Western Front? Source A: a British medical officer's report from a casualty clearing station, 1917: 'Large numbers of men arriving with severe burns to the skin and eyes following a mustard gas attack. Few of these cases are fatal, but recovery is slow and many will not return to duty for weeks.' Source B: a British Army casualty statistics summary comparing the numbers of men affected by, and the numbers who died from, chlorine, phosgene and mustard gas attacks over the course of the war.
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How could you follow up Source A to find out more about how well mustard gas casualties recovered in the longer term? Source A: a British medical officer's report from a casualty clearing station, 1917: 'Large numbers of men arriving with severe burns to the skin and eyes following a mustard gas attack. Few of these cases are fatal, but recovery is slow and many will not return to duty for weeks.'
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