Mustard gas or sulfur mustard is any of the several chemical compounds that contain the chemical structure S(CH2CH2Cl)2. In the wider sense, compounds with the substituent S(CH2CH2X)2 and N(CH2CH2X)3 are known as sulfur mustards and nitrogen mustards, respectively, where X = Cl or Br. Such compounds are potent alkylating agents, which can interfere with several biological processes. Also known as mustard agents, this family of compounds are infamous cytotoxins and blister agents with a long history of use as chemical weapons. The name mustard gas is technically incorrect: the substances, when dispersed, are often not gases but a fine mist of liquid droplets.[4] Sulfur mustards are viscous liquids at room temperature and have an odor resembling mustard plants, garlic, or horseradish, hence the name.[4] When pure, they are colorless, but when used in impure forms, such as in warfare, they are usually yellow-brown. Mustard gases form blisters on exposed skin and in the lungs, often resulting in prolonged illness ending in death. The typical mustard gas is the organosulfur compoundbis(2-chloroethyl) sulfide.[5]
Sulfur mustard is a type of chemical warfare agent. As a chemical weapon, mustard gas was first used in World War I, and has been used in several armed conflicts since then, including the Iran–Iraq War, resulting in more than 100,000 casualties.[6][7] Today, sulfur-based and nitrogen-based mustard agents are regulated under Schedule 1 of the 1993 Chemical Weapons Convention, as substances with few uses other than in chemical warfare (though since then, mustard gas has been found to be useful in cancer chemotherapy[8]). Mustard agents can be deployed by means of artillery shells, aerial bombs, rockets, or by spraying from aircraft.
Mechanism of cellular toxicity
Mustard gas alkylating an amino group via conversion to a sulfonium ion (2-chloroethylthiiranium)
Sulfur mustards readily eliminate chloride ions by intramolecular nucleophilic substitution to form cyclic sulfonium ions. These very reactive intermediates tend to permanently alkylatenucleotides in DNA strands, which can prevent cellular division, leading to programmed cell death.[2] Alternatively, if cell death is not immediate, the damaged DNA can lead to the development of cancer.[2]Oxidative stress would be another pathology involved in mustard gas toxicity.
In the wider sense, compounds with the structural element BC2H4X, where X is any leaving group and B is a Lewis base, are known as mustards.[citation needed] Such compounds can form cyclic "onium" ions (sulfonium, ammonium, etc.) that are good alkylating agents. Other such compounds are bis(2-haloethyl)ethers (oxygen mustards), the (2-haloethyl)amines (nitrogen mustards), and sesquimustard, which has two α-chloroethyl thioether groups (ClC2H4S−) connected by an ethylene bridge (−C2H4−).[citation needed] These compounds have a similar ability to alkylate DNA, but their physical properties vary.
Physiological effects
Soldier with moderate mustard agent burns sustained during World War I showing characteristic bullae on the neck, armpit, and hands
Mustard gases react with DNA, which interferes with cellular division and can lead to mutations.[2]
Mustard gases are extremely toxic and have powerful blistering effects on victims. Their alkylating capabilities make them strongly carcinogenic and mutagenic. Furthermore, they are highly lipophilic, which accelerates their absorption into the body.[2] Because people exposed to mustard agents rarely suffer immediate symptoms, and contaminated areas may appear completely normal, victims can unknowingly receive high doses. Within 24 hours of exposure, they experience intense itching and skin irritation. If this irritation goes untreated, blisters filled with yellow fluid (pus) can form wherever the agent contacted the skin. These are chemical burns and are very debilitating. Mustard gases easily penetrate clothing fabrics such as wool or cotton, so it is not only exposed skin that gets burned. If the victim's eyes were exposed, then they become sore, starting with conjunctivitis (also known as pink eye), after which the eyelids swell, resulting in temporary blindness. Extreme ocular exposure to mustard gas vapors may result in corneal ulceration, anterior chamber scarring, and neovascularization.[9][10][11][12] In these severe and infrequent cases, corneal transplantation has been used as a treatment option.[13]Miosis, when the pupil constricts more than usual, may also occur, which is probably the result of the cholinomimetic activity of mustard.[14] At very high concentrations, if inhaled, mustard agents cause bleeding and blistering within the respiratory system, damaging mucous membranes and causing pulmonary edema. Depending on the level of contamination, mustard agent burns can vary between first and second degree burns, though they can also be every bit as severe, disfiguring, and dangerous as third degree burns.[15] Burns that are severe (i.e. covering more than 50% of the victim's skin) are often fatal, with death occurring after only days or weeks. Mild or moderate exposure to mustard gases is unlikely to kill, though victims still require lengthy periods of medical treatment and convalescence before recovery is complete.
Mustard gases' carcinogenic and mutagenic effects mean that victims, even if they fully recover, have an increased risk of developing cancer later in life. In a study of patients 25 years after wartime exposure to chemical weaponry, c-DNA microarray profiling indicated that 122 genes were significantly mutated in the lungs and airways of mustard gas victims. Those genes all correspond to functions commonly affected by mustard gas exposure, including apoptosis, inflammation, and stress responses.[16] The long-term ocular complications include burning, tearing, itching, photophobia, presbyopia, pain, and foreign-body sensations.[17][18]
Typical appearance of bullae on an arm caused by vesicant burns
Mustard gases' blistering effects can be neutralized by oxidation or chlorination, using household bleach (sodium hypochlorite), or by nucleophilic attack using decontamination solutions such as "DS2" (2% NaOH, 70% diethylenetriamine, 28% 2-methoxyethanol). After initial decontamination of the victim's wounds is complete, medical treatment is similar to that required by any conventional burn. The degree of pain and discomfort suffered by the victim is also comparable. Mustard agent burns do not heal quickly, and (as with other types of burns) present a risk of sepsis caused by pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. The mechanisms behind mustard gas's effect on endothelial cells are still being studied, but recent studies have shown that high levels of exposure can induce high rates of both necrosis and apoptosis. In vitro tests have shown that at low concentrations of mustard gas, where apoptosis is the predominant result of exposure, pretreatment with 50 mM N-acetyl-L-cysteine (NAC) was able to decrease the rate of apoptosis. NAC protects actin filaments from reorganization by mustard gas, demonstrating that actin filaments play a large role in the severe burns observed in victims.[19]
A British nurse treating soldiers with mustard agent burns during World War I commented:[20]
They cannot be bandaged or touched. We cover them with a tent of propped-up sheets. Gas burns must be agonizing because usually the other cases do not complain, even with the worst wounds, but gas cases are invariably beyond endurance and they cannot help crying out.
Formulations
Lewisite (top row) and mustard gas (bottom row) test with concentrations from 0.01% to 0.06%
In its history, various types and mixtures of mustard gas have been employed. These include:
H– Also known as HS ("Hun Stuff") or Levinstein mustard. This is named after the inventor of the "quick but dirty" Levinstein Process for manufacture,[21][22] reacting dry ethylene with disulfur dichloride under controlled conditions. Undistilled mustard gas contains 20–30% impurities, which means it does not store as well as HD. Also, as it decomposes, it increases in vapor pressure, making the munition it is contained in likely to split, especially along a seam, releasing the agent to the atmosphere.[1]
HD– Codenamed Pyro by the British, and Distilled Mustard by the US.[1]Distilled mustard of 95% or higher purity. The term "mustard gas" usually refers to this variety of mustard.
HT– Codenamed Runcol by the British, and Mustard T- mixture by the US.[1] A mixture of 60% HD mustard and 40% O-Mustard, a related vesicant with lower freezing point, lower volatility and similar vesicant characteristics.
HL– A blend of distilled mustard (HD) and lewisite (L), originally intended for use in winter conditions due to its lower freezing point compared to the pure substances. The lewisite component of HL was used as a form of antifreeze.[23]
HQ– A blend of distilled mustard (HD) and sesquimustard (Q) (Gates and Moore 1946).
Yellow Cross– any of several blends containing sulfur mustard and sometimes arsine agents, along with solvents and other additives.
Mustard gases were possibly developed as early as 1822 by César-Mansuète Despretz (1798–1863).[24] Despretz described the reaction of sulfur dichloride and ethylene but never made mention of any irritating properties of the reaction product. In 1854, another French chemist, Alfred Riche (1829–1908), repeated this procedure, also without describing any adverse physiological properties. In 1860, the British scientist Frederick Guthrie synthesized and characterized the mustard agent compound and noted its irritating properties, especially in tasting.[25] Also in 1860, chemist Albert Niemann, known as a pioneer in cocaine chemistry, repeated the reaction, and recorded blister-forming properties. In 1886, Viktor Meyer published a paper describing a synthesis that produced good yields. He combined 2-chloroethanol with aqueouspotassium sulfide, and then treated the resulting thiodiglycol with phosphorus trichloride. The purity of this compound was much higher and consequently the adverse health effects upon exposure were much more severe. These symptoms presented themselves in his assistant, and in order to rule out the possibility that his assistant was suffering from a mental illness (psychosomatic symptoms), Meyer had this compound tested on laboratory rabbits, most of which died. In 1913, the English chemist Hans Thacher Clarke (known for the Eschweiler-Clarke reaction) replaced the phosphorus trichloride with hydrochloric acid in Meyer's formulation while working with Emil Fischer in Berlin. Clarke was hospitalized for two months for burns after one of his flasks broke. According to Meyer, Fischer's report on this accident to the German Chemical Society sent the German Empire on the road to chemical weapons.[26]
Mustard gas can have the effect of turning a patient's skin different colors, including shades of red, orange, pink, and in unusual cases, blue. The German Empire during World War I relied on the Meyer-Clarke method because 2-chloroethanol was readily available from the German dye industry of that time.
Mustard gas was first used in World War I by the German army against British and Canadian soldiers near Ypres, Belgium, "on the night of July 12, 1917."[27] Later also against the French Second Army. Yperite is "a name used by the French, because the compound was first used at Ypres."[28] The Allies did not use mustard gas until November 1917 at Cambrai, France, after the armies had captured a stockpile of German mustard shells. It took the British more than a year to develop their own mustard agent weapon, with production of the chemicals centred on Avonmouth Docks (the only option available to the British was the Despretz–Niemann–Guthrie process).[29][30] This was used first in September 1918 during the breaking of the Hindenburg Line.
Mustard gas was originally assigned the name LOST, after the scientists Wilhelm Lommel and Wilhelm Steinkopf, who developed a method of large-scale production for the Imperial German Army in 1916.[31]
Mustard gas was dispersed as an aerosol in a mixture with other chemicals, giving it a yellow-brown color. Mustard agent has also been dispersed in such munitions as aerial bombs, land mines, mortar rounds, artillery shells, and rockets.[1] Exposure to mustard agent was lethal in about 1% of cases. Its effectiveness was as an incapacitating agent. The early countermeasures against mustard agent were relatively ineffective, since a soldier wearing a gas mask was not protected against absorbing it through his skin and being blistered. A common countermeasure was using a urine-soaked mask or facecloth to prevent or reduce injury, a readily available remedy attested by soldiers in documentaries (e.g. They Shall Not Grow Old in 2018) and others (such as forward aid nurses) interviewed between 1947 and 1981 by the British Broadcasting Corporation for various World War One history programs; however, the effectiveness of this measure is unclear.
Mustard gas can remain in the ground for weeks, and it continues to cause ill effects. If mustard agent contaminates one's clothing and equipment while cold, then other people with whom they share an enclosed space could become poisoned as contaminated items warm up enough material to become an airborne toxic agent. An example of this was depicted in a British and Canadian documentary about life in the trenches, particularly once the "sousterrain" (subways and berthing areas underground) were completed in Belgium and France. Towards the end of World War I, mustard agent was used in high concentrations as an area-denial weapon that forced troops to abandon heavily contaminated areas.
US Army World War II gas identification poster, c.1941–1945
Since World War I, mustard gas has been used in several wars and other conflicts, usually against people who cannot retaliate in kind:[32]
The US military conducted experiments with chemical weapons like lewisite and mustard gas on Japanese American, Puerto Rican and African Americans in the US military in World War II to see how non-white races would react to being mustard gassed, with Rollin Edwards describing it as "It felt like you were on fire, Guys started screaming and hollering and trying to break out. And then some of the guys fainted. And finally they opened the door and let us out, and the guys were just, they were in bad shape." and "It took all the skin off your hands. Your hands just rotted".[36]
After WWII, stockpiled mustard gas was dumped by the British in the sea near Port Elizabeth, South Africa, resulting in many cases of burns among trawler crews[37]
The United States Government tested effectiveness on US Naval recruits in a laboratory setting at The Great Lakes Naval Base, June 3, 1945[38]
Possibly in Sudan against insurgents in the civil war, in 1995 and 1997.[32]
In the Iraq War, abandoned stockpiles of mustard gas shells were destroyed in the open air,[43] and were used against Coalition forces in roadside bombs.[44]
By ISIS forces against Kurdish forces in Iraq in August 2015.[45]
By ISIS against another rebel group in the town of Mare' in 2015.[46]
According to Syrian state media, by ISIS against the Syrian Army during the battle in Deir ez-Zor in 2016.[47]
The use of toxic gases or other chemicals, including mustard gas, during warfare is known as chemical warfare, and this kind of warfare was prohibited by the Geneva Protocol of 1925, and also by the later Chemical Weapons Convention of 1993. The latter agreement also prohibits the development, production, stockpiling, and sale of such weapons.
In September 2012, a US official stated that the rebel militant group ISIS was manufacturing and using mustard gas in Syria and Iraq, which was allegedly confirmed by the group's head of chemical weapons development, Sleiman Daoud al-Afari, who has since been captured.[48][49]
Development of the first chemotherapy drug
As early as 1919 it was known that mustard agent was a suppressor of hematopoiesis.[50] In addition, autopsies performed on 75 soldiers who had died of mustard agent during World War I were done by researchers from the University of Pennsylvania who reported decreased counts of white blood cells.[40] This led the American Office of Scientific Research and Development (OSRD) to finance the biology and chemistry departments at Yale University to conduct research on the use of chemical warfare during World War II.[40][51]
As a part of this effort, the group investigated nitrogen mustard as a therapy for Hodgkin's lymphoma and other types of lymphoma and leukemia, and this compound was tried out on its first human patient in December 1942. The results of this study were not published until 1946, when they were declassified.[51] In a parallel track, after the air raid on Bari in December 1943, the doctors of the U.S. Army noted that white blood cell counts were reduced in their patients. Some years after World War II was over, the incident in Bari and the work of the Yale University group with nitrogen mustard converged, and this prompted a search for other similar chemical compounds. Due to its use in previous studies, the nitrogen mustard called "HN2" became the first cancer chemotherapy drug, chlormethine (also known as mechlorethamine, mustine) to be used. Chlormethine and other mustard gas molecules are still used to this day as an chemotherapy agent albeit they have largely been replaced with more safe chemotherapy drugs like cisplatin and carboplatin.[52]
Disposal
This section needs to be updated. Please help update this article to reflect recent events or newly available information.(February 2022)
In the United States, storage and incineration of mustard gas and other chemical weapons were carried out by the U.S. Army Chemical Materials Agency.[53] Disposal projects at the two remaining American chemical weapons sites were carried out near Richmond, Kentucky, and Pueblo, Colorado. Although not yet declassified,[specify] toxicology specialists who dealt with the accidental puncturing of World War I gas stockpiles add that Air Force bases in Colorado have been made available to assist veterans of the 2003 American war with Iraq in which many Marines were exposed to gas as caches of up to 25,000lb (11,000kg).[citation needed] The United Nations definition of a weapon of mass destruction for mustard gas is 30,000lb (14,000kg), typically the Marines and other coalition allies discovered caches of 25,000 pounds (11,000kg) located across a road from 5,000 pounds (2,300kg) caches as multiple memoirs attest[citation needed]. These were discovered by the assistance of host country allies, or through leaks affecting personnel in an area with a weapon and gas cache called an ASP.[citation needed]
New detection techniques are being developed in order to detect the presence of mustard gas and its metabolites. The technology is portable and detects small quantities of the hazardous waste and its oxidized products, which are notorious for harming unsuspecting civilians. The immunochromatographic assay would eliminate the need for expensive, time-consuming lab tests and enable easy-to-read tests to protect civilians from sulfur-mustard dumping sites.[54]
In 1946, 10,000 drums of mustard gas (2,800 tonnes) stored at the production facility of Stormont Chemicals in Cornwall, Ontario, Canada, were loaded onto 187 boxcars for the 900 miles (1,400km) journey to be buried at sea on board a 400 foot (120m) long barge 40 miles (64km) south of Sable Island, southeast of Halifax, at a depth of 600 fathoms (1,100m). The dump location is 42 degrees, 50 minutes north by 60 degrees, 12 minutes west.[55]
A large British stockpile of old mustard agent that had been made and stored since World War I at M. S. Factory, Valley near Rhydymwyn in Flintshire, Wales, was destroyed in 1958.[56]
Most of the mustard gas found in Germany after World War II was dumped into the Baltic Sea. Between 1966 and 2002, fishermen have found about 700 chemical weapons in the region of Bornholm, most of which contain mustard gas. One of the more frequently dumped weapons was "Sprühbüchse 37" (SprüBü37, Spray Can 37, 1937 being the year of its fielding with the German Army). These weapons contain mustard gas mixed with a thickener, which gives it a tar-like viscosity. When the content of the SprüBü37 comes in contact with water, only the mustard gas in the outer layers of the lumps of viscous mustard hydrolyzes, leaving behind amber-colored residues that still contain most of the active mustard gas. On mechanically breaking these lumps (e.g., with the drag board of a fishing net or by the human hand) the enclosed mustard gas is still as active as it had been at the time the weapon was dumped. These lumps, when washed ashore, can be mistaken for amber, which can lead to severe health problems. Artillery shells containing mustard gas and other toxic ammunition from World War I (as well as conventional explosives) can still be found in France and Belgium. These were formerly disposed of by explosion undersea, but since the current environmental regulations prohibit this, the French government is building an automated factory to dispose of the accumulation of chemical shells.
In 1972, the U.S. Congress banned the practice of disposing of chemical weapons into the ocean by the United States. 29,000 tons of nerve and mustard agents had already been dumped into the ocean off the United States by the U.S. Army. According to a report created in 1998 by William Brankowitz, a deputy project manager in the U.S. Army Chemical Materials Agency, the army created at least 26 chemical weapons dumping sites in the ocean offshore from at least 11 states on both the East Coast and the West Coast (in Operation CHASE, Operation Geranium, etc.). In addition, due to poor recordkeeping, about one-half of the sites have only their rough locations known.[57]
In June 1997, India declared its stock of chemical weapons of 1,044 tonnes (1,151 short tons) of mustard gas.[58][59] By the end of 2006, India had destroyed more than 75 percent of its chemical weapons/material stockpile and was granted extension for destroying the remaining stocks by April 2009 and was expected to achieve 100 percent destruction within that time frame.[58] India informed the United Nations in May 2009 that it had destroyed its stockpile of chemical weapons in compliance with the international Chemical Weapons Convention. With this India has become the third country after South Korea and Albania to do so.[60][61] This was cross-checked by inspectors of the United Nations.
Producing or stockpiling mustard gas is prohibited by the Chemical Weapons Convention. When the convention entered force in 1997, the parties declared worldwide stockpiles of 17,440 tonnes of mustard gas. As of December 2015, 86% of these stockpiles had been destroyed.[62]
A significant portion of the United States' mustard agent stockpile was stored at the Edgewood Area of Aberdeen Proving Ground in Maryland. Approximately 1,621 tons of mustard agents were stored in one-ton containers on the base under heavy guard. A chemical neutralization plant was built on the proving ground and neutralized the last of this stockpile in February 2005. This stockpile had priority because of the potential for quick reduction of risk to the community. The nearest schools were fitted with overpressurization machinery to protect the students and faculty in the event of a catastrophic explosion and fire at the site. These projects, as well as planning, equipment, and training assistance, were provided to the surrounding community as a part of the Chemical Stockpile Emergency Preparedness Program (CSEPP), a joint program of the Army and the Federal Emergency Management Agency (FEMA).[63] Unexploded shells containing mustard gases and other chemical agents are still present in several test ranges in proximity to schools in the Edgewood area, but the smaller amounts of poison gas (4 to 14 pounds (1.8 to 6.4kg)) present considerably lower risks. These remnants are being detected and excavated systematically for disposal. The U.S. Army Chemical Materials Agency oversaw disposal of several other chemical weapons stockpiles located across the United States in compliance with international chemical weapons treaties. These include the complete incineration of the chemical weapons stockpiled in Alabama, Arkansas, Indiana, and Oregon. Earlier, this agency had also completed destruction of the chemical weapons stockpile located on Johnston Atoll located south of Hawaii in the Pacific Ocean.[64] The largest mustard agent stockpile, at approximately 6,200 short tons, was stored at the Deseret Chemical Depot in northern Utah. The incineration of this stockpile began in 2006. In May 2011, the last of the mustard agents in the stockpile were incinerated at the Deseret Chemical Depot, and the last artillery shells containing mustard gas were incinerated in January 2012.
In 2008, many empty aerial bombs that contained mustard gas were found in an excavation at the Marrangaroo Army Base just west of Sydney, Australia.[65][66] In 2009, a mining survey near Chinchilla, Queensland, uncovered 144 105-millimeter howitzer shells, some containing "Mustard H", that had been buried by the U.S. Army during World War II.[66][67]
In 2014, a collection of 200 bombs was found near the Flemish villages of Passendale and Moorslede. The majority of the bombs were filled with mustard agents. The bombs were left over from the German army and were meant to be used in the Battle of Passchendaele in World War I. It was the largest collection of chemical weapons ever found in Belgium.[68]
A large amount of chemical weapons, including mustard gas, was found in a neighborhood of Washington, D.C. The cleanup was completed in 2021.[69]
Post-war accidental exposure
In 2002, an archaeologist at the Presidio Trust archaeology lab in San Francisco was exposed to mustard gas, which had been dug up at the Presidio of San Francisco, a former military base.[70]
In 2010, a clamming boat pulled up some old artillery shells of World War I from the Atlantic Ocean south of Long Island, New York. Multiple fishermen suffered from blistering and respiratory irritation severe enough to require hospitalization.[71]
WWII-era tests on men
Mustard gas test subjects enter gas chamber, Edgewood Arsenal, March 1945
The United States tested sulfur mustards and other chemical agents including nitrogen mustards and lewisite on up to 60,000 servicemen during and after WWII. The experiments were classified secret and as with Agent Orange, claims for medical care and compensation were routinely denied, even after the WWII-era tests were declassified in 1993. The Department of Veterans Affairs stated that it would contact 4,000 surviving test subjects but failed to do so, eventually only contacting 600. Skin cancer, severe eczema, leukemia, and chronic breathing problems plagued the test subjects, some of whom were as young as 19 at the time of the tests, until their deaths, but even those who had previously filed claims with the VA went without compensation.[74]
Concentrations of thiodiglycol in urine have been used to confirm a diagnosis of chemical poisoning in hospitalized victims. The presence in urine of 1,1'-sulfonylbismethylthioethane (SBMTE), a conjugation product with glutathione, is considered a more specific marker, since this metabolite is not found in specimens from unexposed persons. In one case, intact mustard gas was detected in postmortem fluids and tissues of a man who died one week post-exposure.[76]
Nerve agents, sometimes also called nerve gases, are a class of organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase (AChE), an enzyme that catalyzes the breakdown of acetylcholine, a neurotransmitter. Nerve agents are irreversible acetylcholinesterase inhibitors used as poison.
Chemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare, biological warfare and radiological warfare, which together make up CBRN, the military acronym for chemical, biological, radiological, and nuclear, all of which are considered "weapons of mass destruction" (WMDs), a term that contrasts with conventional weapons.
Sarin is an extremely toxic organophosphorus compound. A colourless, odourless liquid, it is used as a chemical weapon due to its extreme potency as a nerve agent. Exposure can be lethal even at very low concentrations, where death can occur within one to ten minutes after direct inhalation of a lethal dose, due to suffocation from respiratory paralysis, unless antidotes are quickly administered. People who absorb a non-lethal dose and do not receive immediate medical treatment may suffer permanent neurological damage.
Soman is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the enzyme cholinesterase. It is an inhibitor of both acetylcholinesterase and butyrylcholinesterase. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN Resolution 687. Its production is strictly controlled, and stockpiling is outlawed by the Chemical Weapons Convention of 1993 where it is classified as a Schedule 1 substance. Soman was the third of the so-called G-series nerve agents to be discovered along with GA (tabun), GB (sarin), and GF (cyclosarin).
The use of toxic chemicals as weapons dates back thousands of years, but the first large-scale use of chemical weapons was during World War I. 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 phosgene, chlorine, and mustard gas. These chemical weapons caused medical problems. This chemical warfare was a major component of the first global war and first total war of the 20th century. The killing capacity of gas was limited, with about 90,000 fatalities from a total of 1.3 million casualties caused by gas attacks. 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 of chemical warfare, 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.
VX is an extremely toxic synthetic chemical compound in the organophosphorus class, specifically, a thiophosphonate. In the class of nerve agents, it was developed for military use in chemical warfare after translation of earlier discoveries of organophosphate toxicity in pesticide research. In its pure form, VX is an oily, relatively non-volatile liquid that is amber-like in colour. Because of its low volatility, VX persists in environments where it is dispersed.
Lewisite (L) (A-243) is an organoarsenic compound. It was once manufactured in the U.S., Japan, Germany and the Soviet Union for use as a chemical weapon, acting as a vesicant and lung irritant. Although the substance is colorless and odorless in its pure form, impure samples of lewisite are a yellow, brown, violet-black, green, or amber oily liquid with a distinctive odor that has been described as similar to geraniums.
The United States is known to have possessed three types of weapons of mass destruction: nuclear, chemical, and biological weapons. The U.S. is the only country to have used nuclear weapons on another country, when it detonated two atomic bombs over two Japanese cities of Hiroshima and Nagasaki during World War II. It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project". The United States pioneered the development of both the nuclear fission and hydrogen bombs. It was the world's first and only nuclear power for four years, from 1945 until 1949, when the Soviet Union produced its own nuclear weapon. The United States has the second-largest number of nuclear weapons in the world, after the Russian Federation.
A blister agent, is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affected. Although the term is often used in connection with large-scale burns caused by chemical spills or chemical warfare agents, some naturally occurring substances such as cantharidin are also blister-producing agents (vesicants). Furanocoumarin, another naturally occurring substance, causes vesicant-like effects indirectly, for example, by increasing skin photosensitivity greatly. Vesicants have medical uses including wart removal but can be dangerous if even small amounts are ingested.
Many nations continue to research and/or stockpile chemical weapon agents despite numerous efforts to reduce or eliminate them. Most states have joined the Chemical Weapons Convention (CWC), which required the destruction of all chemical weapons by 2012. Twelve nations have declared chemical weapons production facilities and six nations have declared stockpiles of chemical weapons. All of the declared production facilities have been destroyed or converted for civilian use after the treaty went into force.
Chlormethine, also known as mechlorethamine, mustine, HN2, and embikhin (эмбихин), is a nitrogen mustard sold under the brand name Mustargen among others. It is the prototype of alkylating agents, a group of anticancer chemotherapeutic drugs. It works by binding to DNA, crosslinking two strands and preventing cell duplication. It binds to the N7 nitrogen on the DNA base guanine. As the chemical is a blister agent, its use is strongly restricted within the Chemical Weapons Convention where it is classified as a Schedule 1 substance.
Sesquimustard is the organosulfur compound with the formula (ClCH2CH2SCH2)2. Although it is a colorless solid, impure samples are often brown. The compound is a type of mustard gas, a vesicant used as a chemical weapon. From the chemical perspective, the compound is both a thioether and an alkyl chloride.
Chemical Agent Identification Sets (CAIS), known by several other names, were sets of glass vials or bottles that contained small amounts of chemical agents. They were employed by all branches of the United States Armed Forces from 1928-1969 for the purpose of training in detection, handling and familiarization with chemical warfare. Most CAIS were destroyed in the 1980s but the U.S. Army Chemical Materials Agency still occasionally demilitarizes CAIS that are found buried.
A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as a weapon "or its precursor that can cause death, injury, temporary incapacitation or sensory irritation through its chemical action. Munitions or other delivery devices designed to deliver chemical weapons, whether filled or unfilled, are also considered weapons themselves."
Chemical weapons were widely used by the United Kingdom in World War I. The use of poison gas was suggested by Winston Churchill and others in Mesopotamia during the interwar period, and also considered in World War II, although it appears that they were not actually used in these conflicts. While the UK was a signatory of the Hague Conventions of 1899 and 1907 which outlawed the use of poison gas shells, the conventions omitted mention of deployment from cylinders.
The United States chemical weapons program began in 1917 during World War I with the creation of the U.S. Army's Gas Service Section and ended 73 years later in 1990 with the country's practical adoption of the Chemical Weapons Convention. Destruction of stockpiled chemical weapons began in 1986 and was completed on July 7, 2023. The U.S. Army Medical Research Institute of Chemical Defense (USAMRICD), at Aberdeen Proving Ground, Maryland, continues to operate.
Chemical weapons have been a part of warfare in most societies for centuries. However, their usage has been extremely controversial since the 20th century.
O-Mustard (T) is a vesicant chemical weapon, a type of mustard gas, with around 3 times the toxicity of the original sulfur mustard. It was developed in England in the 1930s as a thickener for mustard gas to make it more persistent when used in warm climates. A mixture of 60% sulfur mustard and 40% O-mustard also has a lower freezing point than pure sulfur mustard, and was given the code name HT. O-mustard is a Schedule I substance under the Chemical Weapons Convention.
Bis(2-chloroethyl)sulfide is the organosulfur compound with the formula (ClCH2CH2)2S. It is a prominent member of a family of cytotoxic and blister agents known as mustard agents. Sometimes referred to as mustard gas, the term is technically incorrect: bis(2-chloroethyl)sulfide is a liquid at room temperature. In warfare it was dispersed in the form of a fine mist of liquid droplets.
References
Notes
1 2 3 4 5 FM 3–8 Chemical Reference handbook, US Army, 1967
↑ Fries, Amos A. (Amos Alfred); West, Clarence J. (Clarence Jay) (1921). Chemical warfare. University of California Libraries. New York [etc.] McGraw-Hill Book Company, inc. p.176. (...) on the night of July 12, 1917 (...)
↑ Fries, Amos A. (Amos Alfred); West, Clarence J. (Clarence Jay) (1921). Chemical warfare. University of California Libraries. New York [etc.] McGraw-Hill Book Company, inc. p.150. (...) 'Ypres,' a name used by the French, because the compound was first used at Ypres (...)
↑ David Large (ed.). The Port of Bristol, 1848-1884.
↑ Organisation for the Prohibition of Chemical Weapons (30 November 2016). "Annex 3". Report of the OPCW on the Implementation of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction in 2015 (Report). p.42. Retrieved 8 March 2017.
↑ Goodwin, Bridget (1998). Keen as mustard: Britain's horrific chemical warfare experiments in Australia. St. Lucia: University of Queensland Press. ISBN978-0-7022-2941-1.
↑ Dickerson, Caitlin (2015-06-23). "The VA's Broken Promise To Thousands Of Vets Exposed To Mustard Gas". NPR. Retrieved 2019-05-03. ... the Department of Veterans Affairs made two promises: to locate about 4,000 men who were used in the most extreme tests, and to compensate those who had permanent injuries.
↑ Dickerson, Caitlin (2015-06-22). "Secret World War II Chemical Experiments Tested Troops By Race". NPR. Retrieved 2019-05-03. And it wasn't just African-Americans. Japanese-Americans were used [...] so scientists could explore how mustard gas and other chemicals might affect Japanese troops. Puerto Rican soldiers were also singled out.
↑ R. Baselt, Disposition of Toxic Drugs and Chemicals in Man, 10th edition, Biomedical Publications, Seal Beach, CA, 2014, pp. 1892–1894.
Further reading
Cook, Tim. "‘Against God-Inspired Conscience’: The Perception of Gas Warfare as a Weapon of Mass Destruction, 1915–1939." War & Society 18.1 (2000): 47-69.
Dorsey, M. Girard. Holding Their Breath: How the Allies Confronted the Threat of Chemical Warfare in World War II (Cornell UP, 2023) online.
Duchovic, Ronald J., and Joel A. Vilensky. "Mustard gas: its pre-World War I history." Journal of chemical education 84.6 (2007): 944. online
Feister, Alan J. Medical defense against mustard gas: toxic mechanisms and pharmacological implications (1991). online
Fitzgerald, Gerard J. "Chemical warfare and medical response during World War I." American journal of public health 98.4 (2008): 611-625. online
* Freemantle, M. (2012). Gas! GAS! Quick, boys! How Chemistry Changed the First World War. The History Press. ISBN978-0-7524-6601-9.
Geraci, Matthew J. "Mustard gas: imminent danger or eminent threat?." Annals of Pharmacotherapy 42.2 (2008): 237-246. online
Ghabili, Kamyar, et al. "Mustard gas toxicity: the acute and chronic pathological effects." Journal of applied toxicology 30.7 (2010): 627-643. online
Jones, Edgar. "Terror weapons: The British experience of gas and its treatment in the First World War." War in History 21.3 (2014): 355-375. online
Padley, Anthony Paul. "Gas: the greatest terror of the Great War." Anaesthesia and intensive care 44.1_suppl (2016): 24-30. online
Rall, David P., and Constance M. Pechura, eds. Veterans at risk: The health effects of mustard gas and lewisite (1993). online
Richter, Donald (1994). Chemical Soldiers. Leo Cooper. ISBN0850523885.
Schummer, Joachim. "Ethics of chemical weapons research: Poison gas in World War One." Ethics of Chemistry: From Poison Gas to Climate Engineering (2021) pp. 55-83. online
Smith, Susan I. Toxic Exposures: Mustard Gas and the Health Consequences of World War II in the United States (Rutgers University Press, 2017) online book review
Wattana, Monica, and Tareg Bey. "Mustard gas or sulfur mustard: an old chemical agent as a new terrorist threat." Prehospital and disaster medicine 24.1 (2009): 19-29. online
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