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CHEMICAL WARFARE AGENTS

21st March, 2022

History of Chemical Warfare

Ancient Greek myths about Hercules poisoning his arrows with the venom of the Hydra monster are the earliest references to toxic weapons in western literature. Homer's epics, the Iliad and the Odyssey, allude to poisoned arrows used by both sides in the legendary Trojan War (Bronze Age Greece).

Some of the earliest surviving references to toxic warfare appear in the Indian epics Ramayana and Mahabharata. The "Laws of Manu," a Hindu treatise on statecraft (c. 400 BC) forbids the use of poison and fire arrows, but advises poisoning food and water. Kautilya's "Arthashastra", a statecraft manual of the same era, contains hundreds of recipes for creating poison weapons, toxic smokes, and other chemical weapons. Ancient Greek historians recount that Alexander the Great encountered poison arrows and fire incendiaries in India at the Indus basin in the 4th century BC.

In modern warfare, chemical weapons were first used in World War I (1914–18), during which gas warfare inflicted more than one million of the casualties suffered by combatants in that conflict and killed an estimated 90,000. In the years since then, chemical arms have been employed numerous times, most notably in the Iran-Iraq War (1980–88) and the Syrian Civil War.

The United States and the Soviet Union, during their decades of confrontation in the Cold War (1945–91), built up enormous stockpiles of chemical weapons. The end of the Cold War enabled those former adversaries to agree to ban all chemical weapons of the types that had been developed during World War I (first generation), World War II (second generation), and the Cold War (third generation).

 

Chemical Weapon Agent

A chemical weapon agent (CWA), or chemical warfare agent, is a chemical substance whose toxic properties are meant to kill, injure or incapacitate human beings. About 70 different chemicals have been used or stockpiled as chemical weapon agents during the 20th century. These agents may be in liquid, gas or solid form.

In general, chemical weapon agents are organized into several categories (according to the physiological manner in which they affect the human body).

The different types of chemical warfare agents are listed below:

Blister Agents/Vesicants

Chemicals that severely blister the eyes, respiratory tract, and skin on contact

  • Mustards
    • Mustard gas (H) (sulfur mustard)
    • Mustard/lewisite (HL)
    • Nitrogen mustard (HN-1, HN-2, HN-3)
    • Sesqui mustard
    • Sulfur mustard (H) (mustard gas)
  • Lewisites/chloroarsine agents
    • Lewisite (L, L-1, L-2, L-3)
    • Mustard/lewisite (HL)
  • Phosgene oxime (CX) (CX)

Blood Agents

Poisons that affect the body by being absorbed into the blood

  • Arsine (SA) (SA)
  • Carbon Monoxide
  • Cyanide
    • Cyanogen chloride (CK)
    • Hydrogen cyanide (AC)
    • Potassium cyanide (KCN)
    • Sodium cyanide (NaCN)
  • Sodium monofluoroacetate (compound 1080)

Caustics (Acids)

Chemicals that burn or corrode people’s skin, eyes, and mucus membranes (lining of the nose, mouth, throat, and lungs) on contact

  • Hydrofluoric acid (hydrogen fluoride)
  • Hydrogen chloride

Choking/Lung/Pulmonary Agents

Chemicals that cause severe irritation or swelling of the respiratory tract (lining of the nose, throat, and lungs)

  • Ammonia
  • Bromine (CA) (CA)
  • Chlorine (CL)
  • Hydrogen chloride
  • Methyl bromide
  • Methyl isocyanate
  • Osmium tetroxide
  • Phosgene
    • Diphosgene (DP)
    • Phosgene (CG)
  • Phosphine
  • Phosphorus, elemental, white or yellow
  • Sulfuryl fluoride

Incapacitating Agents

Drugs that make people unable to think clearly or that cause an altered state of consciousness (possibly unconsciousness)

  • BZ
  • Fentanyls and other opioids

Long-Acting Anticoagulants

Poisons that prevent blood from clotting properly, which can lead to uncontrolled bleeding

  • Super warfarin

Metals

Agents that consist of metallic poisons

  • Arsenic
  • Barium
  • Mercury
  • Thallium

Nerve Agents

Highly poisonous chemicals that work by preventing the nervous system from working properly

  • G agents
    • Sarin (GB)
    • Soman (GD)
    • Tabun (GA)
  • V agents
    • VX

Organic Solvents

Agents that damage the tissues of living things by dissolving fats and oils

  • Benzene

Riot Control Agents/Tear Gas

Highly irritating agents normally used by law enforcement for crowd control or by individuals for protection (for example, mace)

  • Bromobenzylcyanide (CA)
  • Chloroacetophenone (CN)
  • Chlorobenzylidenemalononitrile (CS)
  • Chloropicrin (PS)
  • Dibenzoxazepine (CR)

Toxic Alcohols

Poisonous alcohols that can damage the heart, kidneys, and nervous system

  • Ethylene glycol

Vomiting Agents

Chemicals that cause nausea and vomiting

  • Adamsite (DM)

 

Chemical Weapons Convention (CWC)

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 the Prohibition of Chemical Weapons (OPCW), an intergovernmental organization based in The Hague, The Netherlands.

The treaty entered into force on 29 April 1997, and prohibits the large-scale use, development, production, stockpiling and transfer of chemical weapons and their precursors, except for very limited purposes (research, medical, pharmaceutical or protective).

The main obligation of member states under the convention is to effect this prohibition, as well as the destruction of all current chemical weapons. All destruction activities must take place under OPCW verification.

The CWC augments the Geneva Protocol of 1925, which bans the use but not the development or possession of chemical and biological weapons. The CWC also includes extensive verification measures such as on-site inspections, in stark contrast to the 1975 Biological Weapons Convention (BWC), which lacks a verification regime.

As of 2021, 193 states have become parties to the CWC and accept its obligations.

Israel has signed but not ratified the agreement, while three other UN member states (Egypt, North Korea and South Sudan) have neither signed nor acceded to the treaty.

Most recently, the State of Palestine deposited its instrument of accession to the CWC on 17 May 2018.

In September 2013, Syria acceded to the convention as part of an agreement for the destruction of Syria's chemical weapons.

As of 2021, 98.39% of the world's declared chemical weapons stockpiles had been destroyed.

The convention has provisions for systematic evaluation of chemical production facilities, as well as for investigations of allegations of use and production of chemical weapons based on the intelligence of other state parties.

Some chemicals which have been used extensively in warfare but have numerous large-scale industrial uses (such as phosgene) are highly regulated; however, certain notable exceptions exist.

Chlorine gas is highly toxic, but being a pure element and widely used for peaceful purposes, is not officially listed as a chemical weapon.

Certain state-powers (e.g. the Assad regime of Syria) continue to regularly manufacture and implement such chemicals in combat munitions.

Although these chemicals are not specifically listed as controlled by the CWC, the use of any toxic chemical as a weapon (when used to produce fatalities solely or mainly through its toxic action) is in-and-of itself forbidden by the treaty.

Other chemicals, such as white phosphorus, are highly toxic but are legal under the CWC when they are used by military forces for reasons other than their toxicity.

Organisation for the Prohibition of Chemical Weapons (OPCW)

Headquarters in The Hague

The convention is administered by the Organisation for the Prohibition of Chemical Weapons (OPCW), which acts as the legal platform for specification of the CWC provisions.

The Conference of the States Parties is mandated to change the CWC and pass regulations on the implementation of CWC requirements.

The Technical Secretariat of the organization conducts inspections to ensure compliance of member states. These inspections target destruction facilities (where permanent monitoring takes place during destruction), chemical weapons production facilities which have been dismantled or converted for civil use, as well as inspections of the chemical industry.

The Secretariat may furthermore conduct "investigations of alleged use" of chemical weapons and give assistance after use of chemical weapons.

Key Objectives of the Convention

  • Prohibition of production and use of chemical weapons
  • Destruction (or monitored conversion to other functions) of chemical weapons production facilities
  • Destruction of all chemical weapons (including chemical weapons abandoned outside the state parties territory)
  • Assistance between State Parties and the OPCW in the case of use of chemical weapons
  • An OPCW inspection regime for the production of chemicals which might be converted to chemical weapons
  • International cooperation in the peaceful use of chemistry in relevant areas.

 

Controlled substances

The convention distinguishes three classes of controlled substance, chemicals that can either be used as weapons themselves or used in the manufacture of weapons. The classification is based on the quantities of the substance produced commercially for legitimate purposes.

Schedule 1

Schedule 1 chemicals have few, or no uses outside chemical weapons. These may be produced or used for research, medical, pharmaceutical or chemical weapon defence testing purposes but production at sites producing more than 100 grams per year must be declared to the OPCW.

A country is limited to possessing a maximum of 1 tonne of these materials. Examples are sulfur mustard and nerve agents, and substances which are solely used as precursor chemicals in their manufacture. A few of these chemicals have very small scale non-military applications, for example, milligram quantities of nitrogen mustard are used to treat certain cancers.

Schedule 2

These chemicals have legitimate small-scale applications. Manufacture must be declared and there are restrictions on export to countries that are not CWC signatories. An example is thiodiglycol which can be used in the manufacture of mustard agents, but is also used as a solvent in inks.

Schedule 3

Schedule 3 chemicals have large-scale uses apart from chemical weapons. Plants which manufacture more than 30 tonnes per year must be declared and can be inspected, and there are restrictions on export to countries which are not CWC signatories.

Examples of these substances are phosgene (the most lethal chemical weapon employed in WWI), which has been used as a chemical weapon but which is also a precursor in the manufacture of many legitimate organic compounds (e.g. pharmaceutical agents and many common pesticides), and triethanolamine, used in the manufacture of nitrogen mustard but also commonly used in toiletries and detergents.

Declaration

A treaty party may declare a "single small-scale facility" that produces up to 1 tonne of Schedule 1 chemicals for research, medical, pharmaceutical or protective purposes each year, and also another facility may produce 10 kg per year for protective testing purposes. An unlimited number of other facilities may produce Schedule 1 chemicals, subject to a total 10 kg annual limit, for research, medical or pharmaceutical purposes, but any facility producing more than 100 grams must be declared.

The treaty also deals with carbon compounds called in the treaty "discrete organic chemicals", the majority of which exhibit moderate-high direct toxicity or can be readily converted into compounds with toxicity sufficient for practical use as a chemical weapon. These are any carbon compounds apart from long chain polymers, oxides, sulfides and metal carbonates, such as organophosphates. The OPCW must be informed of, and can inspect, any plant producing (or expecting to produce) more than 200 tonnes per year, or 30 tonnes if the chemical contains phosphorus, sulfur or fluorine, unless the plant solely produces explosives or hydrocarbons.