Mustard Gas and Gas Masks
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Mustard Gas and Gas Masks
Mustard Gas and Gas Masks in World War I
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developement of mustard gas

developement of mustard gas | Mustard Gas and Gas Masks | Scoop.it

Mustard gas was possibly developed as early as 1822 by César-Mansuète Despretz (1798–1863).[12] Despretez described the reaction of sulfur dichloride and ethylene but never made mention of any irritating properties of the reaction product, which makes the claim doubtful. In 1854, another French chemist Alfred Riche (1829–1908) repeated the procedure but did not describe any adverse physiological properties. In 1860, British scientist Frederick Guthrie synthesized and characterized the compound, and he also noted its irritating properties, especially in tasting.[13] In 1886, chemist Albert Niemann, known as a pioneer in cocaine chemistry, repeated the reaction, but, this time, blister-forming properties were recorded. In 1886, Viktor Meyer published a paper describing a synthesis that produced good yields. He reacted 2-chloroethanol with aqueous potassium sulfide and treated the resulting thiodiglycol with phosphorus trichloride. The purity of this compound was much higher and the adverse health effects on exposure, as a consequence, much more severe. These symptoms presented themselves in an assistant, and, in order to rule out that the assistant was suffering from a mental illness (psychosomatic symptoms), Meyer had the compound tested on rabbits, which then died. In 1913, English chemist Hans Thacher Clarke (of Eschweiler-Clarke fame) replaced phosphorus trichloride with hydrochloric acid in Meyer's recipe while working with Emil Fischer in Berlin. Clarke was hospitalized for 2 months for burns after a flask broke, and, according to him, Fischer's subsequent report on this incident to the German Chemical Society set Germany on the chemical weapons track.[14] Germany in World War I relied on the Meyer-Clarke method with a 2-chloroethanol infrastructure already in place in the dye industry of that time.

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What mustard gas is and how it affects victims

Mustard gas is a substance used in chemical warfare. It is the popular name for the compound with the chemical designation 1,1-thiobis(2-chloroethane) (chemical formula: Cl-CH2-CH2-S-CH2-CH2-Cl). Mustard gas has a number of other names by which it has been known over the years, including H, yprite, sulfur mustard, and Kampstoff Lost. Because the impure substance is said to have an odor similar to that of mustard, garlic, or horseradish, the name mustard gas is most commonly applied. However, in the pure form, mustard gas has neither color nor odor. The gas was used for the first time as an agent of chemical warfare during World War I (1914-1918), when it was distributed with devastating effect near Ypres in Flanders (Belgium) on July 12, 1917.

The synthesis of mustard gas was reported much earlier than its first use as a chemical weapon. In 1860, scientist Frederick Guthrie observed that when ethylene reacted with chlorine a substance was produced which, in small quantities, could produce toxic effects on the skin. Exposure to low concentrations of mustard gas classically causes the reddening and blistering of skin and epithelial tissue. On inhalation, the gas will cause the lining of the lungs to blister and leads to chronic respiratory impairment. Higher concentrations of mustard gas will attack the corneas of the eyes and eventually cause blindness. Exposure to mustard gas can lead to a slow and painful death and any moist area of the body is especially susceptible to its effects. The compound is only slightly soluble in water, but it undergoes a hydrolysis reaction liberating highly corrosive hydrochloric acid and several other vesicant intermediates, which are able to blister epithelial surfaces.

Despite the ease of hydrolysis, mustard gas may be preserved underground in a solid form for up to ten years. The reason for this ability is that in an environment where the concentration of water is relatively low, the reaction pathway proceeds to form an intermediate known as thiodiglycol. In a low moisture environment, most of the water available at the solid surface is used in this reaction. Subsequently, another intermediate in the reaction pathway, a sulfonium ion, reacts with the thiodiglycol in the place of water. This reaction then creates stable, non-reactive sulfonium salts, which can act as a protective layer around the bulk of the solid mustard preventing further degradation.

Mustard gas as a chemical weapon is a particularly deadly and debilitating poison and when it was first used in 1917, it could penetrate all the masks and protective materials that were available at that time. In World War II (1939-1945), several Liberty cargo ships (nicknamed ugly ducklings) were sunk by German U-boats in the port of Bari, Italy (December 2, 1942), while carrying supplies of mustard gas. A cloud of gas spread over the water causing a large loss of life and many injuries (such as burns from the mustard gas). Since then, urethane was found to be resistant to mustard gas. Urethane also has several other advantages for use in combat: it is tough, resistant to cuts, and is stable at a wide range of temperatures.

Detoxification procedures from mustard gas are difficult because of its insolubility and also because of the drastic effects it can have on lung epithelial tissue following inhalation. During World War I, physicians had no curative means of treating the victims of mustard gas exposure. The only method of detoxification that was known involved a rather extreme oxidation procedure using superchlorinated bleaches, such as 5% sodium hypochlorite. Today, several novel methods of detoxification have been developed to counter the effects of mustard gas and these include the use of sulphur-amine solutions and magnesium monoperoxyphthalate. The most effective method to date employs peroxy acids, because they are able to react quickly with the mustard gas. Furthermore, the addition of a catalyst can speed up the detoxification reaction even more effectively.

Although mustard gas has been shown to have long-term carcinogenic properties, it can also be used as an agent in the treatment of cancer. In 1919, it was observed that victims of mustard gas attack had a low white bloodcell count and bone marrow aplasia (tissue growth failure). More detailed research in the years following 1946 showed that nitrogen mustards, which differ from traditional mustard gas by the substitution of a sulphur atom by a nitrogen, could reduce tumor growth in experimental mice by cross-linking DNA (deoxyribonucleic acid) strands. It had been shown previously that the sensitivity of mouse bone marrow to mustard gas was similar to that of humans and more detailed research eventually led to successful clinical trials. Today, nitrogen mustards are part of the spectrum of substances used in modern anti-cancer chemotherapy. They are primarily used in the treatment of conditions such as Hodgkin's disease and cancers of the lymph glands.

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Gas mask description

Gas mask description | Mustard Gas and Gas Masks | Scoop.it

breathing device designed to protect the wearer against harmful substances in the air. The typical gas mask consists of a tight-fitting facepiece that contains filters, an exhalation valve, and transparent eyepieces. It is held to the face by straps and can be worn in association with a protective hood. The filter elements in the cheeks of the mask remove contaminants from the air that is drawn through the mask by the wearer's inhaling. The filters, which can be replaced, clean the air but do not add oxygen to it (some masks are connected by a hose to a separate tank of oxygen). The most common filters employ fibre screens (to strain out finely divided solid particles) and chemical compounds such as charcoal (to capture or chemically alter poisonous gases in the air). Charcoal absorbs and holds a fairly large volume of poisonous gases.

Gas masks are widely used by the world's armed forces. Although it is possible to design filtering devices that will neutralize almost any specific toxic substance in the air, it is impossible to combine in one mask protection against all toxic substances. Military gas masks are accordingly constructed with a view to counteracting those chemicals that are thought most likely to be used in wartime. Gas masks are effective only against those chemical-warfare agents that are dispersed as true gases and are injurious when breathed. Agents such as mustard gas that are dispersed in liquid form and attack the body through the skin surface necessitate the use of special protective clothing in addition to gas masks.

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Effects of mustard gas

Effects of mustard gas | Mustard Gas and Gas Masks | Scoop.it

Blister agents were also developed and deployed in World War I. The primary form of blister agent used in that conflict was sulfur mustard, popularly known as mustard gas. Casualties were inflicted when personnel were attacked and exposed to blister agents like sulfur mustard or lewisite. Delivered in liquid or vapour form, such weapons burned the skin, eyes, windpipe, and lungs. The physical results, depending on level of exposure, might be immediate or might appear after several hours. Although lethal in high concentrations, blister agents seldom kill. Modern blister agents include sulfur mustard, nitrogen mustard, phosgene oxime, phenyldichlorarsine, and lewisite. Protection against blister agents requires an effective gas mask and protective overgarments.

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