Chemical warfare (CW) involves using the

toxic properties Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...

chemical substance A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., wit ...

s as

weapons A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...

. This type of warfare is distinct from

nuclear warfare Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear ...

biological warfare Biological warfare, also known as germ warfare, is the use of biological toxins or infectious agents such as bacteria, viruses, insects, and fungi with the intent to kill, harm or incapacitate humans, animals or plants as an act of war. ...

and radiological warfare, which together make up

CBRN Chemical, biological, radiological and nuclear defence (CBRN defence) are protective measures taken in situations in which chemical, biological, radiological or nuclear warfare (including terrorism) hazards may be present. CBRN defence consi ...

, the military acronym for chemical, biological, radiological, and nuclear (warfare or weapons), all of which are considered "

weapons of mass destruction A weapon of mass destruction (WMD) is a chemical, biological, radiological, nuclear, or any other weapon that can kill and bring significant harm to numerous individuals or cause great damage to artificial structures (e.g., buildings), natu ...

" (WMDs), a term that contrasts with

conventional weapon The terms conventional weapons or conventional arms generally refer to weapons whose ability to damage comes from kinetic, incendiary, or explosive energy and exclude weapons of mass destruction (''e.g.'' nuclear, biological, radiological and ...

s. The use of chemical weapons is prohibited under customary

international humanitarian law International humanitarian law (IHL), also referred to as the laws of armed conflict, is the law that regulates the conduct of war ('' jus in bello''). It is a branch of international law that seeks to limit the effects of armed conflict by pr ...

Definition

Chemical warfare is different from the use of

s or

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bomb ...

s because the destructive effects of

chemical weapon 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 ...

s are not primarily due to any

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...

force. The offensive use of living

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells ( cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and fu ...

s (such as

anthrax Anthrax is an infection caused by the bacterium '' Bacillus anthracis''. It can occur in four forms: skin, lungs, intestinal, and injection. Symptom onset occurs between one day and more than two months after the infection is contracted. The s ...

) is considered

rather than chemical warfare; however, the use of nonliving toxic products produced by living organisms (e.g.

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...

s such as

botulinum toxin Botulinum toxin, or botulinum neurotoxin (BoNT), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neurom ...

ricin Ricin ( ) is a lectin (a carbohydrate-binding protein) and a highly potent toxin produced in the seeds of the castor oil plant, ''Ricinus communis''. The median lethal dose (LD50) of ricin for mice is around 22 micrograms per kilogram of bo ...

, and

saxitoxin Saxitoxin (STX) is a potent neurotoxin and the best-known paralytic shellfish toxin (PST). Ingestion of saxitoxin by humans, usually by consumption of shellfish contaminated by toxic algal blooms, is responsible for the illness known as paralyti ...

) ''is'' considered chemical warfare under the provisions of the

Chemical Weapons Convention The Chemical Weapons Convention (CWC), officially the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, is an arms control treaty administered by the Organisation for ...

(CWC). Under this convention, any toxic chemical, regardless of its origin, is considered a chemical weapon unless it is used for purposes that are not prohibited (an important legal definition known as the

General Purpose Criterion A general officer is an officer of high rank in the armies, and in some nations' air forces, space forces, and marines or naval infantry. In some usages the term "general officer" refers to a rank above colonel."general, adj. and n.". OED ...

). About 70 different chemicals have been used or stockpiled as chemical warfare agents during the 20th century. The entire class known as

Lethal Unitary Chemical Agents and Munitions 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 ...

have been scheduled for elimination by the CWC. Under the convention, chemicals that are toxic enough to be used as chemical weapons, or that may be used to manufacture such chemicals, are divided into three groups according to their purpose and treatment: * Schedule 1 – Have few, if any, legitimate uses. These may only be produced or used for research, medical, pharmaceutical or protective purposes (i.e. testing of chemical weapons sensors and protective clothing). Examples include

nerve agents 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 ...

lewisite 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 (blister agent) and lung irritant. Although the substance is colorless ...

and

mustard gas Mustard gas or sulfur mustard is a chemical compound belonging to a family of cytotoxic and blister agents known as mustard agents. The name ''mustard gas'' is technically incorrect: the substance, when dispersed, is often not actually a gas, ...

. Any production over 100 g must be reported to the

OPCW The Organisation for the Prohibition of Chemical Weapons (OPCW) is an intergovernmental organisation and the implementing body for the Chemical Weapons Convention (CWC), which entered into force on 29 April 1997. The OPCW, with its 193 member s ...

and a country can have a stockpile of no more than one tonne of these chemicals. * Schedule 2 – Have no large-scale industrial uses, but may have legitimate small-scale uses. Examples include dimethyl methylphosphonate, a

precursor Precursor or Precursors may refer to: * Precursor (religion), a forerunner, predecessor ** The Precursor, John the Baptist Science and technology * Precursor (bird), a hypothesized genus of fossil birds that was composed of fossilized parts of u ...

sarin Sarin (NATO designation GB G-series, "B"">Nerve_agent#G-series.html" ;"title="hort for Nerve agent#G-series">G-series, "B" is an extremely toxic synthetic organophosphorus compound.flame retardant The term flame retardants subsumes a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source and ...

, and

thiodiglycol Thiodiglycol, or bis(2-hydroxyethyl)sulfide (also known as 2,2-thiodiethanol or TDE), is the organosulfur compound with the formula S(CH2CH2OH)2. It is miscible with water and polar organic solvents. It is a colorless liquid. It is structurall ...

, a precursor chemical used in the manufacture of mustard gas but also widely used as a solvent in inks. * Schedule 3 – Have legitimate large-scale industrial uses. Examples include

phosgene Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, esp ...

and chloropicrin. Both have been used as chemical weapons but phosgene is an important precursor in the manufacture of plastics and chloropicrin is used as a fumigant. The OPCW must be notified of, and may inspect, any plant producing more than 30 tons per year.

History

Sargent,_John_Singer_(RA)_-_Gassed_-_Google_Art_Project

Simple chemical weapons were used sporadically throughout antiquity and into the Industrial age. It was not until the 19th century that the modern conception of chemical warfare emerged, as various scientists and nations proposed the use of asphyxiating or poisonous gasses. Multiple international treaties were passed banning chemical weapons based upon the alarm of nations and scientists. This however did not prevent the extensive use of chemical weapons in World War I. The development of chlorine gas, among others, was used by both sides to try to break the stalemate of

trench warfare Trench warfare is a type of land warfare using occupied lines largely comprising Trench#Military engineering, military trenches, in which troops are well-protected from the enemy's small arms fire and are substantially sheltered from artille ...

. Though largely ineffective over the long run, it decidedly changed the nature of the war. In many cases the gasses used did not kill, but instead horribly maimed, injured, or disfigured casualties. Some 1.3 million gas casualties were recorded, which may have included up to 260,000 civilian casualties. Fritz_Haber

The interwar years saw occasional use of chemical weapons, mainly to put down rebellions."Chemical Weapons" in ''Historical Dictionary of Ethiopia'', 2d ed. (eds. David H. Shinn & Thomas P. Ofcansky: Scarecrow Press, 2013). In Nazi Germany, much research went into developing new chemical weapons, such as potent

nerve agent 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 ...

s. However, chemical weapons saw little battlefield use in World War II. Both sides were prepared to use such weapons, but the Allied powers never did, and the Axis used them only very sparingly. The reason for the lack of use by the Nazis, despite the considerable efforts that had gone into developing new varieties, might have been a lack of technical ability or fears that the Allies would retaliate with their own chemical weapons. Those fears were not unfounded: the Allies made comprehensive plans for defensive and retaliatory use of chemical weapons, and stockpiled large quantities."Paxman and Harris"
Pakistan p. 132–135.Callum Borchers
Sean Spicer takes his questionable claims to a new level in Hitler-Assad comparison
''The Washington Post'' (April 11, 2017). Japanese forces used them more widely, though only against their Asian enemies, as they also feared that using it on Western powers would result in retaliation. Chemical weapons were frequently used against

Kuomintang The Kuomintang (KMT), also referred to as the Guomindang (GMD), the Nationalist Party of China (NPC) or the Chinese Nationalist Party (CNP), is a major political party in the Republic of China, initially on the Chinese mainland and in Ta ...

and Chinese communist troops. However, the Nazis did extensively use poison gas against civilians in

The Holocaust The Holocaust, also known as the Shoah, was the genocide of European Jews during World War II. Between 1941 and 1945, Nazi Germany and its collaborators systematically murdered some six million Jews across German-occupied Europ ...

. Vast quantities of

Zyklon B Zyklon B (; translated Cyclone B) was the trade name of a cyanide-based pesticide invented in Germany in the early 1920s. It consisted of hydrogen cyanide (prussic acid), as well as a cautionary eye irritant and one of several adsorbents such ...

gas and carbon monoxide were used in the gas chambers of Nazi extermination camps, resulting in the overwhelming majority of some three million deaths. This remains the deadliest use of poison gas in history.Patrick Coffey, ''American Arsenal: A Century of Weapon Technology and Strategy'' (Oxford University Press, 2014), pp. 152–154.James J. Wirtz, "Weapons of Mass Destruction" in ''Contemporary Security Studies'' (4th ed.), ed. Alan Collins, ''Contemporary Security Studies'' (Oxford University Press, 2016), p. 302. The post-war era has seen limited, though devastating, use of chemical weapons. During the Vietnam War, between 1962 and 1971, the United States military sprayed nearly 20,000,000 U.S. gallons (76,000 m³) of various chemicals – the "

rainbow herbicides The Rainbow Herbicides are a group of tactical-use chemicals used by the United States military in Southeast Asia during the Vietnam War. Success with Project AGILE field tests with herbicides in South Vietnam in 1961 and inspiration by the Briti ...

" and defoliants – in Vietnam, eastern Laos, and parts of Cambodia as part of Operation Ranch Hand, reaching its peak from 1967 to 1969. Some 100,000 Iranian troops were casualties of Iraqi chemical weapons during the

Iran–Iraq War The Iran–Iraq War was an armed conflict between Iran and Iraq that lasted from September 1980 to August 1988. It began with the Iraqi invasion of Iran and lasted for almost eight years, until the acceptance of United Nations Security Counci ...

. Iraq used mustard gas and nerve agents against its own civilians in the 1988 Halabja chemical attack.On this day: 1988: Thousands die in Halabja gas attack
BBC News (March 16, 1988). The

Cuban intervention in Angola The Cuban intervention in Angola (codenamed Operation Carlota) began on 5 November 1975, when Cuba sent combat troops in support of the communist-aligned People's Movement for the Liberation of Angola (MPLA) against the pro-western National Un ...

saw limited use of

organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered ...

s. The Syrian government has used

sarin Sarin (NATO designation GB G-series, "B"">Nerve_agent#G-series.html" ;"title="hort for Nerve agent#G-series">G-series, "B" is an extremely toxic synthetic organophosphorus compound.Syrian civil war generally against civilians. Terrorist groups have also used chemical weapons, notably in the Tokyo subway sarin attack and the Matsumoto incident. See also

chemical terrorism Chemical terrorism is the form of terrorism that uses the toxic effects of chemicals to kill, injure, or otherwise adversely affect the interests of its targets. It can broadly be considered a form of chemical warfare. Incidents Use by LTTE in ...

Technology

Although crude chemical warfare has been employed in many parts of the world for thousands of years, "modern" chemical warfare began during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

– see

Chemical weapons in World War I 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 indisc ...

. Initially, only well-known commercially available chemicals and their variants were used. These included

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

and

gas. The methods used to disperse these agents during battle were relatively unrefined and inefficient. Even so, casualties could be heavy, due to the mainly static troop positions which were characteristic features of

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

, the first side to employ chemical warfare on the battlefield, simply opened canisters of chlorine upwind of the opposing side and let the

prevailing winds In meteorology, prevailing wind in a region of the Earth's surface is a surface wind that blows predominantly from a particular direction. The dominant winds are the trends in direction of wind with the highest speed over a particular point on ...

do the dissemination. Soon after, the

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

modified

artillery Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during si ...

munition Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other wea ...

s to contain phosgene – a much more effective method that became the principal means of delivery. Since the development of modern chemical warfare in World War I, nations have pursued

research and development Research and development (R&D or R+D), known in Europe as research and technological development (RTD), is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existi ...

on chemical weapons that falls into four major categories: new and more deadly agents; more efficient methods of delivering agents to the target (dissemination); more reliable means of defense against chemical weapons; and more sensitive and accurate means of detecting chemical agents.

Chemical warfare agents

The chemical used in warfare is called a ''chemical warfare agent'' (''CWA''). About 70 different chemicals have been used or stockpiled as chemical warfare agents during the 20th and 21st centuries. These agents may be in liquid, gas or solid form. Liquid agents that evaporate quickly are said to be ''volatile'' or have a ''high

vapor pressure Vapor pressure (or vapour pressure in English-speaking countries other than the US; see spelling differences) or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed pha ...

''. Many chemical agents are made volatile so they can be dispersed over a large region quickly. The earliest target of chemical warfare agent research was not toxicity, but development of agents that can affect a target through the skin and clothing, rendering protective

gas mask A gas mask is a mask used to protect the wearer from inhaling airborne pollutants and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face. Most gas mas ...

s useless. In July 1917, the Germans employed

sulfur mustard Mustard gas or sulfur mustard is a chemical compound belonging to a family of cytotoxic and blister agents known as mustard agents. The name ''mustard gas'' is technically incorrect: the substance, when dispersed, is often not actually a gas, ...

. Mustard agents easily penetrate leather and fabric to inflict painful burns on the skin. Chemical warfare agents are divided into ''lethal'' and ''incapacitating'' categories. A substance is classified as incapacitating if less than 1/100 of the lethal dose causes incapacitation, e.g., through nausea or visual problems. The distinction between lethal and incapacitating substances is not fixed, but relies on a statistical average called the .

Persistency

Chemical warfare agents can be classified according to their ''persistency'', a measure of the length of time that a chemical agent remains effective after dissemination. Chemical agents are classified as ''persistent'' or ''nonpersistent''. Agents classified as ''nonpersistent'' lose effectiveness after only a few minutes or hours or even only a few seconds. Purely gaseous agents such as chlorine are nonpersistent, as are highly volatile agents such as

sarin Sarin (NATO designation GB G-series, "B"">Nerve_agent#G-series.html" ;"title="hort for Nerve agent#G-series">G-series, "B" is an extremely toxic synthetic organophosphorus compound.VX nerve agent, do not easily evaporate into a gas, and therefore present primarily a contact hazard. The droplet size used for persistent delivery goes up to 1 mm increasing the falling speed and therefore about 80% of the deployed agent reaches the ground, resulting in heavy contamination. Deployment of persistent agents is intended to constrain enemy operations by denying access to contaminated areas. Possible targets include enemy flank positions (averting possible counterattacks), artillery regiments, command posts or supply lines. Because it is not necessary to deliver large quantities of the agent in a short period of time, a wide variety of weapons systems can be used. A special form of persistent agents are thickened agents. These comprise a common agent mixed with thickeners to provide gelatinous, sticky agents. Primary targets for this kind of use include airfields, due to the increased persistency and difficulty of decontaminating affected areas.

Classes

Chemical weapons are agents that come in four categories:

choking Choking, also known as foreign body airway obstruction (FBAO), is a phenomenon that occurs when breathing is impeded by a blockage inside of the respiratory tract. An obstruction that prevents oxygen from entering the lungs results in oxygen dep ...

blister A blister is a small pocket of body fluid ( lymph, serum, plasma, blood, or pus) within the upper layers of the skin, usually caused by forceful rubbing ( friction), burning, freezing, chemical exposure or infection. Most blisters are filled ...

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

and

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the ...

. The agents are organized into several categories according to the manner in which they affect the human body. The names and number of categories varies slightly from source to source, but in general, types of chemical warfare agents are as follows: There are other chemicals used militarily that are not scheduled by the

, and thus are not controlled under the CWC treaties. These include: *

Defoliant A defoliant is any herbicidal chemical sprayed or dusted on plants to cause their leaves to fall off. Defoliants are widely used for the selective removal of weeds in managing croplands and lawns. Worldwide use of defoliants, along with the ...

s and

herbicide Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...

s that destroy vegetation, but are not immediately toxic or poisonous to human beings. Their use is classified as

herbicidal warfare Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an area. Although herbicidal warfare use chemical substances, its main purpose is to disrupt agricultural food production and/or to destroy pl ...

. Some batches of

Agent Orange Agent Orange is a chemical herbicide and defoliant, one of the "tactical use" Rainbow Herbicides. It was used by the U.S. military as part of its herbicidal warfare program, Operation Ranch Hand, during the Vietnam War from 1961 to 1971. It ...

, for instance, used by the British during the

Malayan Emergency The Malayan Emergency, also known as the Anti–British National Liberation War was a guerrilla war fought in British Malaya between communist pro-independence fighters of the Malayan National Liberation Army (MNLA) and the military forces ...

and the United States during the

Vietnam War The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...

, contained dioxins as manufacturing impurities. Dioxins, rather than Agent Orange itself, have long-term cancer effects and for causing genetic damage leading to serious birth defects. * Incendiary or

chemicals (such as

napalm Napalm is an incendiary mixture of a gelling agent and a volatile petrochemical (usually gasoline (petrol) or diesel fuel). The name is a portmanteau of two of the constituents of the original thickening and gelling agents: coprecipitated alu ...

, extensively used by the United States during the

Korean War {{Infobox military conflict , conflict = Korean War , partof = the Cold War and the Korean conflict , image = Korean War Montage 2.png , image_size = 300px , caption = Clockwise from top:{ ...

and the Vietnam War, or

dynamite Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay), and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, Northern Germany, and patented in 1867. It rapidl ...

) because their destructive effects are primarily due to fire or explosive force, and not direct chemical action. Their use is classified as

conventional warfare Conventional warfare is a form of warfare conducted by using conventional weapons and battlefield tactics between two or more states in open confrontation. The forces on each side are well-defined and fight by using weapons that target primari ...

. *

Virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es,

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

, or other organisms. Their use is classified as

Toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...

s produced by living organisms are considered chemical weapons, although the boundary is blurry. Toxins are covered by the Biological Weapons Convention.

Designations

Most chemical weapons are assigned a one- to three-letter "

NATO The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two N ...

weapon designation" in addition to, or in place of, a common name. Binary munitions, in which precursors for chemical warfare agents are automatically mixed in shell to produce the agent just prior to its use, are indicated by a "-2" following the agent's designation (for example, GB-2 and VX-2). Some examples are given below:

Delivery

The most important factor in the effectiveness of chemical weapons is the efficiency of its delivery, or dissemination, to a target. The most common techniques include munitions (such as bombs, projectiles, warheads) that allow dissemination at a distance and spray tanks which disseminate from low-flying aircraft. Developments in the techniques of filling and storage of munitions have also been important. Although there have been many advances in chemical weapon delivery since World War I, it is still difficult to achieve effective dispersion. The dissemination is highly dependent on atmospheric conditions because many chemical agents act in gaseous form. Thus, weather observations and forecasting are essential to optimize weapon delivery and reduce the risk of injuring friendly forces.

Dispersion

Dispersion is placing the chemical agent upon or adjacent to a target immediately before dissemination, so that the material is most efficiently used. Dispersion is the simplest technique of delivering an agent to its target. The most common techniques are munitions, bombs, projectiles, spray tanks and warheads.

saw the earliest implementation of this technique. The actual first chemical ammunition was the

26 mm cartouche suffocante

rifle grenade A rifle grenade is a grenade that uses a rifle-based launcher to permit a longer effective range than would be possible if the grenade were thrown by hand. The practice of projecting grenades with rifle-mounted launchers was first widely used dur ...

, fired from a flare carbine. It contained 35g of the tear-producer

ethyl bromoacetate Ethyl bromoacetate is the chemical compound with the formula CH2BrCO2C2H5. It is the ethyl ester of bromoacetic acid and is prepared in two steps from acetic acid. It is a lachrymator and has a fruity, pungent odor. It is also a highly toxic alk ...

, and was used in autumn 1914 – with little effect on the Germans. The

Germans , native_name_lang = de , region1 = , pop1 = 72,650,269 , region2 = , pop2 = 534,000 , region3 = , pop3 = 157,000 3,322,405 , region4 = , pop4 = ...

contrarily tried to increase the effect of 10.5 cm

shrapnel shell Shrapnel shells were anti-personnel artillery munitions which carried many individual bullets close to a target area and then ejected them to allow them to continue along the shell's trajectory and strike targets individually. They relied almo ...

s by adding an irritant –

dianisidine chlorosulfonate ''o''-Dianisidine is an organic compound with the formula CH3O)(H2N)C6H3sub>2. A colorless or white solid, it is a bifunctional compound derived via the benzidine rearrangement from ''o''-anisidine. ''o''-Dianisidine is a precursor to some azo ...

. Its use went unnoticed by the British when it was used against them at

Neuve Chapelle Neuve-Chapelle ( vls, Nieuwkappel) is a commune in the Pas-de-Calais department in the Hauts-de-France region of France. It was the site of a First World War battle in 1915. Geography Neuve-Chapelle is situated some northeast of Béthune and ...

in October 1914. Hans Tappen, a chemist in the Heavy Artillery Department of the War Ministry, suggested to his brother, the Chief of the Operations Branch at German General Headquarters, the use of the tear-gases

benzyl bromide Benzyl bromide is an organic compound with the formula . The molecule consists of a benzene ring substituted with a bromomethyl group. It is a colorless liquid with lachrymatory properties. The compound is a reagent for introducing benzyl groups ...

or xylyl bromide. Shells were tested successfully at the Wahn artillery range near

Cologne Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western state of North Rhine-Westphalia (NRW) and the fourth-most populous city of Germany with 1.1 million inhabitants in the city proper and 3.6 millio ...

on January 9, 1915, and an order was placed for 15 cm

howitzer A howitzer () is a long- ranged weapon, falling between a cannon (also known as an artillery gun in the United States), which fires shells at flat trajectories, and a mortar, which fires at high angles of ascent and descent. Howitzers, like ot ...

shells, designated 'T-shells' after Tappen. A shortage of shells limited the first use against the Russians at

Bolimów Bolimów is a town in Skierniewice County, Łódź Voivodeship, in central Poland. It is the seat of the Gmina (administrative district) called Gmina Bolimów. It lies approximately north of Skierniewice and north-east of the regional capital ...

on January 31, 1915; the liquid failed to vaporize in the cold weather, and again the experiment went unnoticed by the Allies. The first effective use were when the German forces at the

Second Battle of Ypres During the First World War, the Second Battle of Ypres was fought from for control of the tactically important high ground to the east and south of the Flemish town of Ypres in western Belgium. The First Battle of Ypres had been fought the pr ...

simply opened cylinders of

and allowed the

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ...

to carry the gas across enemy lines. While simple, this technique had numerous disadvantages. Moving large numbers of heavy gas cylinders to the front-line positions from where the gas would be released was a lengthy and difficult logistical task. Poison Gas Attack Germany and Russia 1916

Poison Gas Attack Germany and Russia 1916

Stockpiles of cylinders had to be stored at the front line, posing a great risk if hit by artillery shells. Gas delivery depended greatly on

wind speed In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed ...

and direction. If the wind was fickle, as at Loos, the gas could blow back, causing friendly casualties. Gas clouds gave plenty of warning, allowing the enemy time to protect themselves, though many soldiers found the sight of a creeping gas cloud unnerving. This made the gas doubly effective, as, in addition to damaging the enemy physically, it also had a psychological effect on the intended victims. Another disadvantage was that gas clouds had limited penetration, capable only of affecting the front-line trenches before dissipating. Although it produced limited results in World War I, this technique shows how simple chemical weapon dissemination ''can'' be. Shortly after this "open canister" dissemination, French forces developed a technique for delivery of

in a non-explosive

shell. This technique overcame many of the risks of dealing with gas in cylinders. First, gas shells were independent of the wind and increased the effective range of gas, making any target within reach of guns vulnerable. Second, gas shells could be delivered without warning, especially the clear, nearly odorless phosgenethere are numerous accounts of gas shells, landing with a "plop" rather than exploding, being initially dismissed as dud

high explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ...

s, giving the gas time to work before the soldiers were alerted and took precautions. The major drawback of artillery delivery was the difficulty of achieving a killing concentration. Each shell had a small gas payload and an area would have to be subjected to saturation bombardment to produce a cloud to match cylinder delivery. A British solution to the problem was the

Livens Projector The Livens Projector was a simple mortar-like weapon that could throw large drums filled with flammable or toxic chemicals. In the First World War, the Livens Projector became the standard means of delivering gas attacks by the British Army an ...

. This was effectively a large-bore mortar, dug into the ground that used the gas cylinders themselves as projectiles – firing a 14 kg cylinder up to 1500 m. This combined the gas volume of cylinders with the range of artillery. Over the years, there were some refinements in this technique. In the 1950s and early 1960s, chemical artillery rockets and

cluster bomb A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller submunitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill personnel and destroy vehicl ...

s contained a multitude of submunitions, so that a large number of small clouds of the chemical agent would form directly on the target.

Thermal dissemination

Thermal dissemination is the use of

s or

pyrotechnic Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. ...

s to deliver chemical agents. This technique, developed in the 1920s, was a major improvement over earlier dispersal techniques, in that it allowed significant quantities of an agent to be disseminated over a considerable distance. Thermal dissemination remains the principal method of disseminating chemical agents today. Most thermal dissemination devices consist of a

bomb A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechan ...

or projectile shell that contains a chemical agent and a central "burster" charge; when the burster detonates, the agent is expelled laterally. Thermal dissemination devices, though common, are not particularly efficient. First, a percentage of the agent is lost by incineration in the initial blast and by being forced onto the ground. Second, the sizes of the particles vary greatly because explosive dissemination produces a mixture of liquid droplets of variable and difficult to control sizes. The efficacy of thermal detonation is greatly limited by the flammability of some agents. For flammable

aerosols An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of a ...

, the cloud is sometimes totally or partially ignited by the disseminating explosion in a phenomenon called ''flashing''. Explosively disseminated VX will ignite roughly one third of the time. Despite a great deal of study, flashing is still not fully understood, and a solution to the problem would be a major technological advance. Despite the limitations of central bursters, most nations use this method in the early stages of chemical weapon development, in part because standard munitions can be adapted to carry the agents. Soviet chemical weapons canisters from a stockpile in Albania

Soviet chemical weapons canisters from a stockpile in Albania

Aerodynamic dissemination

Aerodynamic dissemination is the non-explosive delivery of a chemical agent from an aircraft, allowing aerodynamic stress to disseminate the agent. This technique is the most recent major development in chemical agent dissemination, originating in the mid-1960s. This technique eliminates many of the limitations of thermal dissemination by eliminating the flashing effect and theoretically allowing precise control of particle size. In actuality, the altitude of dissemination, wind direction and velocity, and the direction and velocity of the aircraft greatly influence particle size. There are other drawbacks as well; ideal deployment requires precise knowledge of

aerodynamics Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dy ...

and

fluid dynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) a ...

, and because the agent must usually be dispersed within the

boundary layer In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces a no-slip boundary cond ...

(less than above the ground), it puts pilots at risk. Significant research is still being applied toward this technique. For example, by modifying the properties of the liquid, its breakup when subjected to aerodynamic stress can be controlled and an idealized particle distribution achieved, even at

supersonic speed Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...

. Additionally, advances in fluid dynamics,

computer model Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...

ing, and

weather forecasting Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for millennia and formally since the 19th cen ...

allow an ideal direction, speed, and altitude to be calculated, such that warfare agent of a predetermined particle size can predictably and reliably hit a target.

Protection against chemical warfare

Ideal protection begins with nonproliferation treaties such as the

, and detecting, very early, the ''signatures'' of someone building a chemical weapons capability. These include a wide range of intelligence disciplines, such as economic analysis of exports of

dual-use In politics, diplomacy and export control, dual-use items refers to goods, software and technology that can be used for both civilian and military applications.

chemicals and equipment, human intelligence (

HUMINT Human intelligence (abbreviated HUMINT and pronounced as ''hyoo-mint'') is intelligence gathered by means of interpersonal contact, as opposed to the more technical intelligence gathering disciplines such as signals intelligence (SIGINT), imager ...

) such as diplomatic, refugee, and agent reports; photography from satellites, aircraft and drones ( IMINT); examination of captured equipment ( TECHINT); communications intercepts ( COMINT); and detection of chemical manufacturing and chemical agents themselves (

MASINT Measurement and signature intelligence (MASINT) is a technical branch of intelligence gathering, which serves to detect, track, identify or describe the distinctive characteristics (signatures) of fixed or dynamic target sources. This often incl ...

). If all the preventive measures fail and there is a clear and present danger, then there is a need for detection of chemical attacks, collective protection, and decontamination. Since industrial accidents can cause dangerous chemical releases (e.g., the

Bhopal disaster The Bhopal disaster, also referred to as the Bhopal gas tragedy, was a chemical accident on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh, India. Considered the world's ...

), these activities are things that civilian, as well as military, organizations must be prepared to carry out. In civilian situations in

developed countries A developed country (or industrialized country, high-income country, more economically developed country (MEDC), advanced country) is a sovereign state that has a high quality of life, developed economy and advanced technological infrastruct ...

, these are duties of

HAZMAT Dangerous goods, abbreviated DG, are substances that when transported are a risk to health, safety, property or the environment. Certain dangerous goods that pose risks even when not being transported are known as hazardous materials ( syllabi ...

organizations, which most commonly are part of fire departments. Detection has been referred to above, as a technical

discipline; specific military procedures, which are usually the model for civilian procedures, depend on the equipment, expertise, and personnel available. When chemical agents are detected, an

alarm An alarm device is a mechanism that gives an audible, visual or other kind of alarm signal to alert someone to a problem or condition that requires urgent attention. Alphabetical musical instruments Etymology The word ''alarm'' comes from t ...

needs to sound, with specific warnings over emergency broadcasts and the like. There may be a warning to expect an attack. If, for example, the captain of a

US Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

ship believes there is a serious threat of chemical, biological, or radiological attack, the crew may be ordered to set Circle William, which means closing all openings to outside air, running breathing air through filters, and possibly starting a system that continually washes down the exterior surfaces. Civilian authorities dealing with an attack or a toxic chemical accident will invoke the Incident Command System, or local equivalent, to coordinate defensive measures. Individual protection starts with a

and, depending on the nature of the threat, through various levels of protective clothing up to a complete chemical-resistant suit with a self-contained air supply. The US military defines various levels of MOPP (mission-oriented protective posture) from mask to full chemical resistant suits; Hazmat suits are the civilian equivalent, but go farther to include a fully independent air supply, rather than the filters of a gas mask. Collective protection allows continued functioning of groups of people in buildings or shelters, the latter which may be fixed, mobile, or improvised. With ordinary buildings, this may be as basic as plastic sheeting and tape, although if the protection needs to be continued for any appreciable length of time, there will need to be an air supply, typically an enhanced gas mask.

Decontamination

Decontamination varies with the particular chemical agent used. Some ''nonpersistent'' agents, including most pulmonary agents (

, and so on), blood gases, and nonpersistent nerve gases (e.g., GB), will dissipate from open areas, although powerful exhaust fans may be needed to clear out buildings where they have accumulated. In some cases, it might be necessary to neutralize them chemically, as with

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...

as a neutralizer for

hydrogen cyanide Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on a ...

. Riot control agents such as CS will dissipate in an open area, but things contaminated with CS powder need to be aired out, washed by people wearing protective gear, or safely discarded. Mass decontamination is a less common requirement for people than equipment, since people may be immediately affected and treatment is the action required. It is a requirement when people have been contaminated with persistent agents. Treatment and decontamination may need to be simultaneous, with the medical personnel protecting themselves so they can function. There may need to be immediate intervention to prevent death, such as injection of

atropine Atropine is a tropane alkaloid and anticholinergic medication used to treat certain types of nerve agent and pesticide poisonings as well as some types of slow heart rate, and to decrease saliva production during surgery. It is typically given ...

for nerve agents. Decontamination is especially important for people contaminated with persistent agents; many of the fatalities after the explosion of a WWII US ammunition ship carrying sulfur mustard, in the harbor of Bari, Italy, after a German bombing on December 2, 1943, came when rescue workers, not knowing of the contamination, bundled cold, wet seamen in tight-fitting blankets. For decontaminating equipment and buildings exposed to persistent agents, such as

blister agent A blister agent (or vesicant), 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 affec ...

s, VX or other agents made persistent by mixing with a thickener, special equipment and materials might be needed. Some type of neutralizing agent will be needed; e.g. in the form of a spraying device with neutralizing agents such as Chlorine, Fichlor, strong alkaline solutions or enzymes. In other cases, a specific chemical decontaminant will be required.

Sociopolitical climate

There are many instances of the use of chemical weapons in battles documented in Greek and Roman historical texts; the earliest example was the deliberate poisoning of Kirrha's water supply with hellebore in the First Sacred War, Greece, about 590 BC. One of the earliest reactions to the use of chemical agents was from

Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus ( legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ...

. Struggling to defend themselves from the

Roman legion The Roman legion ( la, legiō, ) was the largest military unit of the Roman army, composed of 5,200 infantry and 300 equites (cavalry) in the period of the Roman Republic (509 BC–27 BC) and of 5,600 infantry and 200 auxilia in the period o ...

s, Germanic tribes poisoned the wells of their enemies, with Roman jurists having been recorded as declaring "armis bella non venenis geri", meaning "war is fought with

weapon A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...

s, not with

poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

s." Yet the Romans themselves resorted to poisoning wells of besieged cities in Anatolia in the 2nd century BCE.Mayor 2003 Before 1915 the use of poisonous chemicals in battle was typically the result of local initiative, and not the result of an active government chemical weapons program. There are many reports of the isolated use of chemical agents in individual battles or

siege A siege is a military blockade of a city, or fortress, with the intent of conquering by attrition, or a well-prepared assault. This derives from la, sedere, lit=to sit. Siege warfare is a form of constant, low-intensity conflict characteriz ...

s, but there was no true tradition of their use outside of

incendiaries Incendiary weapons, incendiary devices, incendiary munitions, or incendiary bombs are weapons designed to start fires or destroy sensitive equipment using fire (and sometimes used as anti-personnel weaponry), that use materials such as napalm, th ...

and smoke. Despite this tendency, there have been several attempts to initiate large-scale implementation of poison gas in several wars, but with the notable exception of World War I, the responsible authorities generally rejected the proposals for ethical reasons or fears of retaliation. For example, in 1854 Lyon Playfair (later 1st Baron Playfair, GCB, PC, FRS (1818–1898), a British chemist, proposed using a cacodyl cyanide-filled

shell against enemy ships during the

Crimean War The Crimean War, , was fought from October 1853 to February 1856 between Russia and an ultimately victorious alliance of the Ottoman Empire, France, the United Kingdom and Piedmont-Sardinia. Geopolitical causes of the war included the ...

. The British Ordnance Department rejected the proposal as "as bad a mode of warfare as poisoning the wells of the enemy."

Efforts to eradicate chemical weapons

* August 27, 1874: The

Brussels Declaration Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...

Concerning the Laws and Customs of War is signed, specifically forbidding the "employment of poison or poisoned weapons", although the treaty was not adopted by any nation whatsoever and it never went into effect. * September 4, 1900: The First Hague Convention, which includes a declaration banning the "use of projectiles the object of which is the diffusion of asphyxiating or deleterious gases," enters into force. * January 26, 1910: The Second Hague Convention enters into force, prohibiting the use of "poison or poisoned weapons" in warfare. * February 6, 1922: After World War I, the Washington Arms Conference Treaty prohibited the use of asphyxiating, poisonous or other gases. It was signed by the United States, Britain, Japan, France, and Italy, but France objected to other provisions in the treaty and it never went into effect. * February 8, 1928: The Geneva Protocol enters into force, prohibiting the use of "asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices" and "bacteriological methods of warfare".

Chemical weapon proliferation

Despite numerous efforts to reduce or eliminate them, some nations continue to research and/or stockpile chemical warfare agents. To the right is a summary of the nations that have either declared weapon stockpiles or are suspected of secretly stockpiling or possessing CW research programs. Notable examples include

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

and

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

. In 1997, future US Vice President

Dick Cheney Richard Bruce Cheney ( ; born January 30, 1941) is an American politician and businessman who served as the 46th vice president of the United States from 2001 to 2009 under President George W. Bush. He is currently the oldest living former ...

opposed the signing ratification of a treaty banning the use of chemical weapons, a recently unearthed letter shows. In a letter dated April 8, 1997, then Halliburton-CEO Cheney told Sen.

Jesse Helms Jesse Alexander Helms Jr. (October 18, 1921 – July 4, 2008) was an American politician. A leader in the conservative movement, he served as a senator from North Carolina from 1973 to 2003. As chairman of the Senate Foreign Relations Committe ...

, the chairman of the Senate Foreign Relations Committee, that it would be a mistake for America to join the convention. "Those nations most likely to comply with the

are not likely to ever constitute a military threat to the United States. The governments we should be concerned about are likely to cheat on the CWC, even if they do participate," reads the letter, published by the

Federation of American Scientists The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1946 by scientists who w ...

. The CWC was ratified by the Senate that same month. Since then, Albania, Libya, Russia, the United States, and India have declared over 71,000 metric tons of chemical weapon stockpiles, and destroyed about a third of them. Under the terms of the agreement, the United States and Russia agreed to eliminate the rest of their supplies of chemical weapons by 2012. Not having met its goal, the U.S. government estimates remaining stocks will be destroyed by 2017.

Chemical weapons destruction

India

In June 1997, India declared that it had a stockpile of 1044 tons of sulphur mustard in its possession. India's declaration of its stockpile came after its entry into the

, that created the

Organisation for the Prohibition of Chemical Weapons The Organisation for the Prohibition of Chemical Weapons (OPCW) is an intergovernmental organisation and the implementing body for the Chemical Weapons Convention (CWC), which entered into force on 29 April 1997. The OPCW, with its 193 member ...

, and on January 14, 1993, India became one of the original signatories to the

. By 2005, from among six nations that had declared their possession of chemical weapons, India was the only country to meet its deadline for chemical weapons destruction and for inspection of its facilities by the

. By 2006, India had destroyed more than 75 percent of its chemical weapons and material stockpile and was granted an extension to complete a 100 percent destruction of its stocks by April 2009. On May 14, 2009, India informed the

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoni ...

that it has completely destroyed its stockpile of chemical weapons.

Iraq

The Director-General of the

, Ambassador Rogelio Pfirter, welcomed Iraq's decision to join the OPCW as a significant step to strengthening global and regional efforts to prevent the spread and use of chemical weapons. The OPCW announced "The government of Iraq has deposited its instrument of accession to the Chemical Weapons Convention with the Secretary General of the United Nations and within 30 days, on 12 February 2009, will become the 186th State Party to the Convention". Iraq has also declared stockpiles of chemical weapons, and because of their recent accession is the only State Party exempted from the destruction time-line.

Japan

During the

Second Sino-Japanese War The Second Sino-Japanese War (1937–1945) or War of Resistance (Chinese term) was a military conflict that was primarily waged between the Republic of China and the Empire of Japan. The war made up the Chinese theater of the wider Pacific T ...

(1937–1945) Japan stored chemical weapons on the territory of

mainland China "Mainland China" is a geopolitical term defined as the territory governed by the China, People's Republic of China (including islands like Hainan or Chongming Island, Chongming), excluding dependent territories of the PRC, and other territorie ...

. The weapon stock mostly containing sulfur mustard-lewisite mixture. The weapons are classified as abandoned chemical weapons under the

, and from September 2010 Japan has started their destruction in Nanjing using mobile destruction facilities in order to do so.

Russia

Russia signed into the

on January 13, 1993, and ratified it on November 5, 1995. Declaring an arsenal of 39,967 tons of chemical weapons in 1997, by far the largest arsenal, consisting of blister agents:

Lewisite 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 (blister agent) and lung irritant. Although the substance is colorless ...

Sulfur mustard Mustard gas or sulfur mustard is a chemical compound belonging to a family of cytotoxic and blister agents known as mustard agents. The name ''mustard gas'' is technically incorrect: the substance, when dispersed, is often not actually a gas, ...

, Lewisite-mustard mix, and nerve agents:

Sarin Sarin (NATO designation GB G-series, "B"">Nerve_agent#G-series.html" ;"title="hort for Nerve agent#G-series">G-series, "B" is an extremely toxic synthetic organophosphorus compound.Soman Soman (or GD, EA 1210, Zoman, PFMP, A-255, systematic name: ''O''-pinacolyl methylphosphonofluoridate) is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiti ...

, and VX. Russia met its treaty obligations by destroying 1 percent of its chemical agents by the 2002 deadline set out by the Chemical Weapons Convention, but requested an extension on the deadlines of 2004 and 2007 due to technical, financial, and environmental challenges of chemical disposal. Since, Russia has received help from other countries such as Canada which donated C$100,000, plus a further C$100,000 already donated, to the Russian Chemical Weapons Destruction Program. This money will be used to complete work at Shchuch'ye and support the construction of a chemical weapons destruction facility at Kizner (Russia), where the destruction of nearly 5,700 tons of nerve agent, stored in approximately 2 million artillery shells and munitions, will be undertaken. Canadian funds are also being used for the operation of a Green Cross Public Outreach Office, to keep the civilian population informed on the progress made in chemical weapons destruction activities. As of July 2011, Russia has destroyed 48 percent (18,241 tons) of its stockpile at destruction facilities located in Gorny (Saratov Oblast) and Kambarka (Udmurt Republic) – where operations have finished – and Schuch'ye (Kurgan Oblast), Maradykovsky (Kirov Oblast), Leonidovka (Penza Oblast) whilst installations are under construction in Pochep (Bryansk Oblast) and Kizner (Udmurt Republic). As August 2013, 76 percent (30,500 tons) were destroyed, and Russia leaves the

Cooperative Threat Reduction A cooperative (also known as co-operative, co-op, or coop) is "an autonomous association of persons united voluntarily to meet their common economic, social and cultural needs and aspirations through a jointly owned and democratically-control ...

(CTR) Program, which partially funded chemical weapons destruction. In September 2017, OPCW announced that Russia had destroyed its entire chemical weapons stockpile.

United States

On November 25, 1969, President

Richard Nixon Richard Milhous Nixon (January 9, 1913April 22, 1994) was the 37th president of the United States, serving from 1969 to 1974. A member of the Republican Party, he previously served as a representative and senator from California and was ...

unilaterally renounced the offensive use of biological and toxic weapons, but the U.S. continued to maintain an offensive chemical weapons program.Jonathan B. Tucker & Erin R. Mahan
Case Study 1: President Nixon's Decision to Renounce the U.S. Offensive Biological Weapons Program
Case Studies Series, Center for the Study of Weapons of Mass Destruction, National Defense University (October 2009). From May 1964 to the early 1970s the U.S. participated in

Operation CHASE Operation CHASE (an acronym for "Cut Holes And Sink 'Em") was a United States Department of Defense program for the disposal of unwanted munitions at sea from May 1964 until the early 1970s.Kurak, Steve "Operation Chase" ''United States Naval Instit ...

, a

United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national sec ...

program that aimed to dispose of chemical weapons by sinking ships laden with the weapons in the deep Atlantic. After the

Marine Protection, Research, and Sanctuaries Act of 1972 Marine Protection, Research and Sanctuaries Act of 1972 (MPRSA) or Ocean Dumping Act is one of several key environmental laws passed by the US Congress in 1972. The Act has two essential aims: to regulate intentional ocean disposal of materials, ...

, Operation Chase was scrapped and safer disposal methods for chemical weapons were researched, with the U.S. destroying several thousand tons of sulfur mustard by incineration at the Rocky Mountain Arsenal, and nearly 4,200 tons of nerve agent by chemical neutralisation at Tooele Army Depot. The U.S. began stockpile reductions in the 1980s with the removal of outdated munitions and destroying its entire stock of

3-Quinuclidinyl benzilate 3-Quinuclidinyl benzilate (QNB) (IUPAC name 1-azabicyclo .2.2ctan-3-yl hydroxy(diphenyl)acetate; US Army code EA-2277; NATO code BZ; Soviet code Substance 78) is an odorless and bitter-tasting military incapacitating agent.QNB: Incapacitating Age ...

(BZ or Agent 15) at the beginning of 1988. In June 1990 the

Johnston Atoll Chemical Agent Disposal System Johnston Atoll Chemical Agent Disposal System (JACADS) was the U.S. Army's first chemical munitions disposal facility. It was located on Johnston Island, at Johnston Atoll and completed its mission and ceased operation in 2000. Background Prior ...

began destruction of chemical agents stored on the

Johnston Atoll Johnston Atoll is an unincorporated territory of the United States, currently administered by the United States Fish and Wildlife Service (USFWS). Johnston Atoll is a National Wildlife Refuge and part of the Pacific Remote Islands Marine Nati ...

in the Pacific, seven years before the Chemical Weapons Treaty came into effect. In 1986 President Ronald Reagan made an agreement with the Chancellor, Helmut Kohl to remove the U.S. stockpile of chemical weapons from Germany. In 1990, as part of

Operation Steel Box Operation Steel Box, also known as Operation Golden Python (German name for the transport in Germany: Aktion Lindwurm), was a 1990 joint U.S.-West German operation which moved over 100,000 U.S. chemical weapons from Germany to Johnston Atoll. Bac ...

, two ships were loaded with over 100,000 shells containing

Sarin Sarin (NATO designation GB G-series, "B"">Nerve_agent#G-series.html" ;"title="hort for Nerve agent#G-series">G-series, "B" is an extremely toxic synthetic organophosphorus compound.VX were taken from the U.S. Army weapons storage depots such as Miesau and then-classified FSTS (Forward Storage / Transportation Sites) and transported from Bremerhaven, Germany to Johnston Atoll in the Pacific, a 46-day nonstop journey. In the 1980s, Congress, at the urging of the

Reagan administration Ronald Reagan's tenure as the 40th president of the United States began with his first inauguration on January 20, 1981, and ended on January 20, 1989. Reagan, a Republican from California, took office following a landslide victory over ...

, Congress provided funding for the manufacture of

binary chemical weapon __NOTOC__ Binary chemical weapons or munitions are chemical weapons which contain the toxic agent in its active state as chemical precursors that are significantly less toxic than the agent. This improves the safety of storing, transporting, and di ...

s (sarin artillery shells) from 1987 until 1990, but this was halted after the U.S. and the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...

entered into a bilateral agreement in June 1990. In the 1990 agreement, the U.S. and Soviet Union agreed to begin destroying their chemical weapons stockpiles before 1993 and to reduce them to no more than 5,000 agent tons each by the end of 2002. The agreement also provided for exchanges of data and inspections of sites to verify destruction.Andrew Glass
Deal reached curbing chemical weapons, June 1, 1990
''Politico'' (June 1, 2017). Following the

collapse of the Soviet Union The dissolution of the Soviet Union, also negatively connoted as rus, Разва́л Сове́тского Сою́за, r=Razvál Sovétskogo Soyúza, ''Ruining of the Soviet Union''. was the process of internal disintegration within the Sov ...

, the U.S.'s Nunn–Lugar Cooperative Threat Reduction program helped eliminate some of the chemical, biological and nuclear stockpiles of the

former Soviet Union The post-Soviet states, also known as the former Soviet Union (FSU), the former Soviet Republics and in Russia as the near abroad (russian: links=no, ближнее зарубежье, blizhneye zarubezhye), are the 15 sovereign states that wer ...

. The

Conference on Disarmament in

Geneva Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaking part of Switzerland. Situa ...

in 1980 led to the development of the

(CWC), a

multilateral treaty A multilateral treaty is a treaty to which two or more sovereign states are parties. Each party owes the same obligations to all other parties, except to the extent that they have stated reservations. Examples of multilateral treaties include the ...

that prohibited the development, production, stockpiling, and use of chemical weapons, and required the elimination of existing stockpiles.Jonathan B. Tucker
Case Study 4, U.S. Ratification of the Chemical Weapons Convention
''Case Studies Series'', Center for the Study of Weapons of Mass Destruction,

National Defense University The National Defense University (NDU) is an institution of higher education funded by the United States Department of Defense, intended to facilitate high-level education, training, and professional development of national security leaders. As ...

(December 2011). The treaty expressly prohibited state parties from making reservations (unilateral caveats). During the Reagan administration and the George H. W. Bush administration, the U.S. participated in the negotiations toward the CWC. The CWC was concluded on September 3, 1992, and opened for signature on January 13, 1993. The U.S. became one of 87 original state parties to the CWC. President

Bill Clinton William Jefferson Clinton (né Blythe III; born August 19, 1946) is an American politician who served as the 42nd president of the United States from 1993 to 2001. He previously served as governor of Arkansas from 1979 to 1981 and again ...

submitted it to the U.S. Senate for ratification on November 23, 1993. Ratification was blocked in the Senate for years, largely as a result of opposition from Senator

, the chairman of the Senate Foreign Relations Committee. On April 24, 1997, the Senate gave its consent to ratification of the CWC by a 74–26 vote (satisfying the required two-thirds majority). The U.S. deposited its instrument of ratification at the United Nations on April 25, 1997, a few days before the CWC entered into force. The U.S. ratification allowed the U.S. to participate in the

, the organization based in

The Hague The Hague ( ; nl, Den Haag or ) is a city and municipality of the Netherlands, situated on the west coast facing the North Sea. The Hague is the country's administrative centre and its seat of government, and while the official capital o ...

that oversees implementation of the CWC. Upon U.S. ratification of the CWC, the U.S. declared a total of 29,918 tons of chemical weapons, and committed to destroying all of the U.S.'s chemical weapons and bulk agent.Owen LeGrone
U.S. Begins Final CW Destruction
''Arms Controls Today'', Arms Control Association (July/August 2019). The U.S. was one of eight states to declare a stockpile of chemical weapons and to commit to their safe elimination.US Chemical Weapons Stockpile Elimination: Progress Update
Arms Control Association (September 23, 2021). The U.S. committed in the CWC to destroy its entire chemical arsenal within 10 years of the entry into force (''i.e.'', by April 29, 2007), However, at a 2012 conference,
Centers for Disease Control and Prevention (January 6, 2014). the parties to the CWC parties agreed to extend the U.S. deadline to 2023. By 2012, stockpiles had been eliminated at seven of the U.S.'s nine chemical weapons depots and 89.75% of the 1997 stockpile was destroyed.Army Agency Completes Mission to Destroy Chemical Weapons
, USCMA, January 21, 2012 The depots were the Aberdeen Chemical Agent Disposal Facility, Anniston Chemical Disposal Facility,

Newport Chemical Agent Disposal Facility The Newport Chemical Depot, previously known as the Wabash River Ordnance Works and the Newport Army Ammunition Plant, was a bulk chemical storage and destruction facility that was operated by the United States Army. It is located near Newpor ...

, Pine Bluff Chemical Disposal Facility, Tooele Chemical Disposal Facility, Umatilla Chemical Disposal Facility, and

Deseret Chemical Depot The Deseret Chemical Depot () was a U.S. Army chemical weapon storage area located in Utah, 60 miles (100 km) southwest of Salt Lake City. It is related to the Tooele Chemical Agent Disposal Facility. History The area was used to store chemi ...

. The U.S. closed each site after the completion of stockpile destruction. In 2019, the U.S. began to eliminate its chemical-weapon stockpile at the last of the nine U.S. chemical weapons storage facilities: the

Blue Grass Army Depot Blue Grass Army Depot (BGAD) is a U.S. Army Joint Munitions Command storage facility for conventional munitions and chemical weapons. The facility is located in east central Kentucky, southeast of the cities of Lexington and Richmond, Kentucky. ...

in Kentucky. By May 2021, the U.S. destroyed all of its Category 2 and Category 3 chemical weapons and 96.52% of its Category 1 chemical weapons. The U.S. is scheduled to complete the elimination of all its chemical weapons by the September 2023 deadline. The U.S. has maintained a " calculated ambiguity" policy that warns potential adversaries that a chemical or biological attack against the U.S. or its allies will prompt a "overwhelming and devastating" response. The policy deliberately leaves open the question of whether the U.S. would respond to a chemical attempt with

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

retaliation Revenge is committing a harmful action against a person or group in response to a grievance, be it real or perceived. Francis Bacon described revenge as a kind of "wild justice" that "does... offend the law ndputteth the law out of office." Pr ...

. Commentators have noted that this policy gives policymakers more flexibility, at the possible cost of decreased strategic unpreparedness.

Anti-agriculture

Herbicidal warfare

A vietnamese Professor is pictured with a group of handicapped children

Although herbicidal warfare use

s, its main purpose is to disrupt agricultural food production and/or to destroy plants which provide cover or concealment to the enemy. The use of

s by the U.S. military during the

has left tangible, long-term impacts upon the Vietnamese people and U.S. veterans of the war. The government of Vietnam says that around 24% of the forests of Southern Vietnam were defoliated and up to four million people in Vietnam were exposed to Agent Orange. They state that as many as three million people have developed illness because of Agent Orange while the Red Cross of Vietnam estimates that up to one million people were disabled or have health problems associated with Agent Orange. The United States government has described these figures as unreliable. During the war, the U.S. fought the North Vietnamese and their allies in

Laos Laos (, ''Lāo'' )), officially the Lao People's Democratic Republic ( Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ, French: République démocratique populaire lao), is a socialist s ...

and

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailand ...

, dropping large quantities of Agent Orange in each of those countries. According on one estimate, the U.S. dropped of Agent Orange in Laos and in Cambodia.The Atlantic, 20 Jul. 2019
"The U.S.'s Toxic Agent Orange Legacy: Washington Has Admitted to the Long-Lasting Effects of Dioxin Use in Vietnam, But Has Largely Sidestepped the Issue in Neighboring Cambodia and Laos"
/ref> Because Laos and Cambodia were officially neutral during the Vietnam War, the U.S. attempted to keep secret its military involvement in these countries. The U.S. has stated that Agent Orange was not widely used and therefore hasn't offered assistance to affected Cambodians or Laotians, and limits benefits American veterans and CIA personnel who were stationed there.

Anti-livestock

During the

Mau Mau Uprising The Mau Mau rebellion (1952–1960), also known as the Mau Mau uprising, Mau Mau revolt or Kenya Emergency, was a war in the British Kenya Colony (1920–1963) between the Kenya Land and Freedom Army (KLFA), also known as the ''Mau Mau'', an ...

in 1952, the poisonous

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

of the African milk bush was used to kill cattle.

Notes

References

* CBWInfo.com (2001)
A Brief History of Chemical and Biological Weapons: Ancient Times to the 19th Century
Retrieved November 24, 2004. * Chomsky, Noam (March 4, 2001).

', page 2. Lecture. * Cordette, Jessica, MPH(c) (2003)
Chemical Weapons of Mass Destruction
Retrieved November 29, 2004. * * Smart, Jeffery K., M.A. (1997)

Retrieved November 24, 2004. * United States Senate, 103d Congress, 2d Session. (May 25, 1994)
The Riegle Report
Retrieved November 6, 2004. * Gerard J Fitzgerald. American Journal of Public Health. Washington: Apr 2008. Vol. 98, Iss. 4; p. 611 *

External links

Official website
of the

(OPCW)
Rule 74. The use of chemical weapons is prohibited.
– section on chemical weapons from ''Customary IHL Database'', an "updated version of the Study on customary

conducted by the

International Committee of the Red Cross The International Committee of the Red Cross (ICRC; french: Comité international de la Croix-Rouge) is a humanitarian organization which is based in Geneva, Switzerland, and it is also a three-time Nobel Prize Laureate. State parties (signato ...

(ICRC) and originally published by

Cambridge University Press Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by King Henry VIII in 1534, it is the oldest university press in the world. It is also the King's Printer. Cambridge University Pr ...

."
Chemical Warfare information page
, from the Disaster Information Management Research Center of the

U.S. Department of Health and Human Services The United States Department of Health and Human Services (HHS) is a cabinet-level executive branch department of the U.S. federal government created to protect the health of all Americans and providing essential human services. Its motto is " ...

including links to relevant sources in the U.S. National Library of Medicine {{DEFAULTSORT:Chemical Warfare Warfare by type