Tabun (nerve agent)
Encyclopedia
Tabun or GA is an extremely toxic chemical substance. It is a clear, colorless, and tasteless liquid with a faint fruity odor. It is classified as a nerve agent
because it fatally interferes with normal functioning of the mammalian nervous system. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations
according to UN Resolution 687, and its production is strictly controlled and stockpiling outlawed by the Chemical Weapons Convention
of 1993. Tabun is the first of the so-called G-series nerve agents along with GB
(sarin), GD
(soman) and GF
(cyclosarin).
Although pure tabun is clear, less-pure tabun may be brown. It is a volatile
chemical, although less so than either sarin or soman; because of this, tabun can be used to contaminate water.
Tabun can be destroyed with bleaching powder, though the poisonous gas cyanogen chloride
is produced.
. In the chemical agent factory in Dyhernfurth an der Oder
, codenamed "Hochwerk", at least 12,000 metric tons of this agent were manufactured between 1942 and 1945. The manufacturing process consisted of two steps, first being reaction of gaseous dimethylamine
(1) with an excess of phosphoryl chloride
(2), yielding dimethylamidophosphoric dichloride (3, codenamed "Produkt 39" or "D 4") and dimethylammonium chloride (4). Dimethylamidophosphoric dichloride thus obtained was purified by vacuum distillation and thereafter transferred to the main Tabun production line. Here it was reacted with an excess of sodium cyanide
(5), dispersed in dry chlorobenzene
, yielding the intermediate dimethylamidophosphoric dicyanide (not depicted in the scheme) and sodium chloride
(8); then, absolute ethanol
(6) was added, reacting with the dimethylamidophosphoric dicyanide to yield tabun (7) and hydrogen cyanide (9). After the reaction, the mixture (consisting of about 75% chlorobenzene and 25% tabun, along insoluble salts and rests of hydrogen cyanide) was filtered so as to remove the insoluble salts and vacuum-distilled to remove hydrogen cyanide and excess chlorobenzene to finally yield the technical product, consisting either of 95% tabun with 5% chlorobenzene (Tabun A), or later in the war, 80% tabun with 20% chlorobenzene (Tabun B).
/restlessness
, miosis
(contraction of the pupil), rhinorrhea
(runny nose), excessive salivation, dyspnea
(difficulty in breathing due to bronchoconstriction
/secretions), sweating
, bradycardia
(slow heartbeat), loss of consciousness
, convulsion
s, flaccid paralysis
, loss of bladder and bowel control, apnea
(breathing stopped) and lung blisters. The exact symptoms of overexposure are similar to those created by all nerve agent
s. Tabun is toxic even in minute doses. The number and severity of symptoms which appear vary according to the amount of the agent absorbed and rate of entry of it into the body. Very small skin dosages sometimes cause local sweating and tremors accompanied with characteristically constricted pupils with few other effects. Tabun is about half as toxic as sarin by inhalation, but in very low concentrations it is more irritating to the eyes than sarin. Also, tabun breaks down slowly, which after repeated exposure can lead to build up in the body
.
The effects of tabun appear slowly when tabun is absorbed through the skin rather than inhaled. A victim may absorb a lethal dose quickly, although death may be delayed for one to two hours. A person's clothing can release the toxic chemical for up to 30 minutes after exposure. Inhaled lethal dosages kill in one to ten minutes, and liquid absorbed through the eye
s kills almost as fast. However, people who experience mild to moderate exposure to tabun can recover completely, if treated almost as soon as exposure occurred. The LCt50
for tabun is about 400 mg-min/m3
Treatment for suspected tabun poisoning is often three injections of a nerve agent antidote, such as atropine
. Pralidoxime chloride (2-PAM Cl) also works as an antidote; however, it must be administered within minutes to a few hours following exposure to be effective.
researcher Gerhard Schrader
. Schrader was experimenting with a class of compounds called organophosphate
s, which kill insects by interrupting their nervous systems, in order to create a more effective insecticide
for IG Farben
, a German chemical and pharmaceutical industry conglomerate, at Elberfield. Instead of a new insecticide, he discovered tabun, a chemical enormously toxic to humans as well as insects.
During World War II
, as part of the Grün 3 program, a plant for the manufacture of tabun was established at Dyhernfurth (now Brzeg Dolny
, Poland
), in 1939. Run by Anorgana, GmbH, the plant finally began production of the substance in 1942. The reason that the plant took so long to get started was the extreme precautions used by the plant. Intermediate products of tabun were corrosive, and had to be contained in quartz or silver-lined vessels. Tabun itself was also highly toxic, and final reactions were conducted behind double glass walls. Large scale manufacturing of the agent resulted in problems with tabun's degradation over time, and only around 12,500 tons of material were manufactured before the plant was seized by the Soviet Army
. The plant initially produced shells and aerial bombs using a 95:5 mix of tabun and chlorobenzene
, designated "Variant A", and in the latter half of the war switched to "Variant B," a 80:20 mix of tabun and chlorobenzene designed for easier dispersion. The Soviets dismantled the plant and shipped it to Russia
.
The United States once had a tabun production program, which ended many decades ago. Like the other Allied governments, the Soviets soon abandoned GA for GB and GD. Large quantities of the German-manufactured agent were dumped into the sea to neutralize the substance.
Since GA is much easier to produce than the other G-series weapons and the process is comparatively widely understood, countries that develop a nerve agent capability but lack advanced industrial facilities often start by producing GA.
In his 1970s-1980s tracts to the medias, U.S. conspiracy theorist Francis E. Dec
often claimed the use of tabun (misspelled "tabin") as a covert assassination tool in the U.S.
During the Iran–Iraq War, Iraq employed quantities of chemical weapons against Iranian ground forces. Although the most commonly used agents were mustard gas and sarin
, tabun and cyclosarin
were also used.
Nerve agent
Nerve agents are a class of phosphorus-containing organic chemicals that disrupt the mechanism by which nerves transfer messages to organs...
because it fatally interferes with normal functioning of the mammalian nervous system. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations
United Nations
The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...
according to UN Resolution 687, and its production is strictly controlled and stockpiling outlawed by the Chemical Weapons Convention
Chemical Weapons Convention
The Chemical Weapons Convention is an arms control agreement which outlaws the production, stockpiling and use of chemical weapons. Its full name is the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction...
of 1993. Tabun is the first of the so-called G-series nerve agents along with GB
Sarin
Sarin, or GB, is an organophosphorus compound with the formula [2CHO]CH3PF. It is a colorless, odorless liquid, which is used as a chemical weapon. It has been classified as a weapon of mass destruction in UN Resolution 687...
(sarin), GD
Soman
Soman, or GD , is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the cholinesterase enzyme. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN...
(soman) and GF
Cyclosarin
Cyclosarin or GF is an extremely toxic substance used as a chemical weapon. It is a member of the G-series family of nerve agents, a group of chemical weapons discovered and synthesized by a German team led by Dr. Gerhard Schrader. The major nerve gases are the G agents, sarin , soman, tabun, and...
(cyclosarin).
Although pure tabun is clear, less-pure tabun may be brown. It is a volatile
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...
chemical, although less so than either sarin or soman; because of this, tabun can be used to contaminate water.
Tabun can be destroyed with bleaching powder, though the poisonous gas cyanogen chloride
Cyanogen chloride
Cyanogen chloride is an inorganic compound with the formula NCCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-temperature solid that is widely used in biochemical analysis and...
is produced.
Synthesis
Tabun was manufactured on an industrial scale by Germany during World War II, based on a process developed by Dr. Gerhard SchraderGerhard Schrader
Dr. Gerhard Schrader was a German chemist specializing in the discovery of new insecticides, hoping to make progress in the fight against hunger in the world. However, Dr...
. In the chemical agent factory in Dyhernfurth an der Oder
Brzeg Dolny
Brzeg Dolny is a town in Wołów County, Lower Silesian Voivodeship in south-western Poland. It is located north-west of Wrocław on the Oder River, and is the site of a large chemical complex, PCC Rokita SA...
, codenamed "Hochwerk", at least 12,000 metric tons of this agent were manufactured between 1942 and 1945. The manufacturing process consisted of two steps, first being reaction of gaseous dimethylamine
Dimethylamine
Dimethylamine is an organic compound with the formula 2NH. This secondary amine is a colorless, flammable liquified gas with an ammonia-like odor. Dimethylamine is generally encountered as a solution in water at concentrations up to around 40%...
(1) with an excess of phosphoryl chloride
Phosphoryl chloride
Phosphoryl chloride is a colourless liquid with the formula 3. It hydrolyses in moist air to phosphoric acid to release choking fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosphorus trichloride and oxygen or phosphorus pentoxide...
(2), yielding dimethylamidophosphoric dichloride (3, codenamed "Produkt 39" or "D 4") and dimethylammonium chloride (4). Dimethylamidophosphoric dichloride thus obtained was purified by vacuum distillation and thereafter transferred to the main Tabun production line. Here it was reacted with an excess of sodium cyanide
Sodium cyanide
Sodium cyanide is an inorganic compound with the formula NaCN. This highly toxic colorless salt is used mainly in gold mining but has other niche applications...
(5), dispersed in dry chlorobenzene
Chlorobenzene
Chlorobenzene is an aromatic organic compound with the chemical formula C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.-Uses:...
, yielding the intermediate dimethylamidophosphoric dicyanide (not depicted in the scheme) and sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
(8); then, absolute ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
(6) was added, reacting with the dimethylamidophosphoric dicyanide to yield tabun (7) and hydrogen cyanide (9). After the reaction, the mixture (consisting of about 75% chlorobenzene and 25% tabun, along insoluble salts and rests of hydrogen cyanide) was filtered so as to remove the insoluble salts and vacuum-distilled to remove hydrogen cyanide and excess chlorobenzene to finally yield the technical product, consisting either of 95% tabun with 5% chlorobenzene (Tabun A), or later in the war, 80% tabun with 20% chlorobenzene (Tabun B).
Effects of overexposure
The symptoms of exposure include: nervousnessAnxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
/restlessness
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, miosis
Miosis
Miosis is the constriction of the pupil of the eye to two millimeters or less...
(contraction of the pupil), rhinorrhea
Rhinorrhea
Rhinorrhea or rhinorrhoea is a condition where the nasal cavity is filled with a significant amount of mucous fluid. The condition, commonly known as "runny nose", occurs relatively frequently and is not usually considered dangerous. Rhinorrhea is a common symptom of allergies or certain diseases,...
(runny nose), excessive salivation, dyspnea
Dyspnea
Dyspnea , shortness of breath , or air hunger, is the subjective symptom of breathlessness.It is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations...
(difficulty in breathing due to bronchoconstriction
Bronchoconstriction
Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath. Bronchoconstriction can also be due to an accumulation of thick mucus....
/secretions), sweating
Sweating
Perspiration is the production of a fluid consisting primarily of water as well as various dissolved solids , that is excreted by the sweat glands in the skin of mammals...
, bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
(slow heartbeat), loss of consciousness
Faint
Faint may refer to:* Syncope , a medical term for fainting* Faint , a song by Linkin Park* Feint, a maneuver designed to distract or mislead* Feint , a song by Epica* The Faint, a dance-punk/rock band....
, convulsion
Convulsion
A convulsion is a medical condition where body muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body. Because a convulsion is often a symptom of an epileptic seizure, the term convulsion is sometimes used as a synonym for seizure...
s, flaccid paralysis
Flaccid paralysis
Flaccid paralysis is a clinical manifestation characterized by weakness or paralysis and reduced muscle tone without other obvious cause .-Polio:...
, loss of bladder and bowel control, apnea
Apnea
Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...
(breathing stopped) and lung blisters. The exact symptoms of overexposure are similar to those created by all nerve agent
Nerve agent
Nerve agents are a class of phosphorus-containing organic chemicals that disrupt the mechanism by which nerves transfer messages to organs...
s. Tabun is toxic even in minute doses. The number and severity of symptoms which appear vary according to the amount of the agent absorbed and rate of entry of it into the body. Very small skin dosages sometimes cause local sweating and tremors accompanied with characteristically constricted pupils with few other effects. Tabun is about half as toxic as sarin by inhalation, but in very low concentrations it is more irritating to the eyes than sarin. Also, tabun breaks down slowly, which after repeated exposure can lead to build up in the body
Bioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
.
The effects of tabun appear slowly when tabun is absorbed through the skin rather than inhaled. A victim may absorb a lethal dose quickly, although death may be delayed for one to two hours. A person's clothing can release the toxic chemical for up to 30 minutes after exposure. Inhaled lethal dosages kill in one to ten minutes, and liquid absorbed through the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
s kills almost as fast. However, people who experience mild to moderate exposure to tabun can recover completely, if treated almost as soon as exposure occurred. The LCt50
LD50
In toxicology, the median lethal dose, LD50 , LC50 or LCt50 of a toxin, radiation, or pathogen is the dose required to kill half the members of a tested population after a specified test duration...
for tabun is about 400 mg-min/m3
Treatment for suspected tabun poisoning is often three injections of a nerve agent antidote, such as atropine
Atropine
Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...
. Pralidoxime chloride (2-PAM Cl) also works as an antidote; however, it must be administered within minutes to a few hours following exposure to be effective.
History
Tabun was the first nerve agent to be discovered by accident in January 1936 by the GermanGermany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
researcher Gerhard Schrader
Gerhard Schrader
Dr. Gerhard Schrader was a German chemist specializing in the discovery of new insecticides, hoping to make progress in the fight against hunger in the world. However, Dr...
. Schrader was experimenting with a class of compounds called organophosphate
Organophosphate
An organophosphate is the general name for esters of phosphoric acid. Phosphates are probably the most pervasive organophosphorus compounds. Many of the most important biochemicals are organophosphates, including DNA and RNA as well as many cofactors that are essential for life...
s, which kill insects by interrupting their nervous systems, in order to create a more effective insecticide
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
for IG Farben
IG Farben
I.G. Farbenindustrie AG was a German chemical industry conglomerate. Its name is taken from Interessen-Gemeinschaft Farbenindustrie AG . The company was formed in 1925 from a number of major companies that had been working together closely since World War I...
, a German chemical and pharmaceutical industry conglomerate, at Elberfield. Instead of a new insecticide, he discovered tabun, a chemical enormously toxic to humans as well as insects.
During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, as part of the Grün 3 program, a plant for the manufacture of tabun was established at Dyhernfurth (now Brzeg Dolny
Brzeg Dolny
Brzeg Dolny is a town in Wołów County, Lower Silesian Voivodeship in south-western Poland. It is located north-west of Wrocław on the Oder River, and is the site of a large chemical complex, PCC Rokita SA...
, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
), in 1939. Run by Anorgana, GmbH, the plant finally began production of the substance in 1942. The reason that the plant took so long to get started was the extreme precautions used by the plant. Intermediate products of tabun were corrosive, and had to be contained in quartz or silver-lined vessels. Tabun itself was also highly toxic, and final reactions were conducted behind double glass walls. Large scale manufacturing of the agent resulted in problems with tabun's degradation over time, and only around 12,500 tons of material were manufactured before the plant was seized by the Soviet Army
Soviet Army
The Soviet Army is the name given to the main part of the Armed Forces of the Soviet Union between 1946 and 1992. Previously, it had been known as the Red Army. Informally, Армия referred to all the MOD armed forces, except, in some cases, the Soviet Navy.This article covers the Soviet Ground...
. The plant initially produced shells and aerial bombs using a 95:5 mix of tabun and chlorobenzene
Chlorobenzene
Chlorobenzene is an aromatic organic compound with the chemical formula C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.-Uses:...
, designated "Variant A", and in the latter half of the war switched to "Variant B," a 80:20 mix of tabun and chlorobenzene designed for easier dispersion. The Soviets dismantled the plant and shipped it to Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
.
The United States once had a tabun production program, which ended many decades ago. Like the other Allied governments, the Soviets soon abandoned GA for GB and GD. Large quantities of the German-manufactured agent were dumped into the sea to neutralize the substance.
Since GA is much easier to produce than the other G-series weapons and the process is comparatively widely understood, countries that develop a nerve agent capability but lack advanced industrial facilities often start by producing GA.
In his 1970s-1980s tracts to the medias, U.S. conspiracy theorist Francis E. Dec
Francis E. Dec
Francis E. Dec was a U.S. lawyer from Hempstead Village, New York, disbarred for fraud in 1959, and later known for the bizarre socio-political tracts of conspiracy theories he mass-mailed to the media...
often claimed the use of tabun (misspelled "tabin") as a covert assassination tool in the U.S.
During the Iran–Iraq War, Iraq employed quantities of chemical weapons against Iranian ground forces. Although the most commonly used agents were mustard gas and sarin
Sarin
Sarin, or GB, is an organophosphorus compound with the formula [2CHO]CH3PF. It is a colorless, odorless liquid, which is used as a chemical weapon. It has been classified as a weapon of mass destruction in UN Resolution 687...
, tabun and cyclosarin
Cyclosarin
Cyclosarin or GF is an extremely toxic substance used as a chemical weapon. It is a member of the G-series family of nerve agents, a group of chemical weapons discovered and synthesized by a German team led by Dr. Gerhard Schrader. The major nerve gases are the G agents, sarin , soman, tabun, and...
were also used.
See also
- CyclosarinCyclosarinCyclosarin or GF is an extremely toxic substance used as a chemical weapon. It is a member of the G-series family of nerve agents, a group of chemical weapons discovered and synthesized by a German team led by Dr. Gerhard Schrader. The major nerve gases are the G agents, sarin , soman, tabun, and...
(GF) - Deseret Chemical DepotDeseret Chemical DepotThe Deseret Chemical Depot is a U.S. Army chemical weapon storage area located in Utah, 60 miles southwest of Salt Lake City. It is related to the Tooele Chemical Agent Disposal Facility.-History:...
- location of remaining US stockpile - Nerve agentNerve agentNerve agents are a class of phosphorus-containing organic chemicals that disrupt the mechanism by which nerves transfer messages to organs...
- SarinSarinSarin, or GB, is an organophosphorus compound with the formula [2CHO]CH3PF. It is a colorless, odorless liquid, which is used as a chemical weapon. It has been classified as a weapon of mass destruction in UN Resolution 687...
(GB) - SomanSomanSoman, or GD , is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the cholinesterase enzyme. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN...
(GD)
Further reading
- United States Senate, 103d Congress, 2d Session. (May 25, 1994). Material Safety Data Sheet—Lethal Nerve Agent Tabun (GA). Retrieved Nov. 6, 2004.
- United States Central Intelligence Agency (Jul. 15, 1996) Stability of Iraq's Chemical Weapon Stockpile