Chemical weapons

Download this factsheet as a two-page PDF

What are chemical weapons?
When have they been used?
Efforts to ban chemical weapons
How are chemical weapons destroyed?

  What are chemical weapons?

About 70 different chemicals have been used or stockpiled as Chemical weapons (CW) agents during the 20th century. These chemicals are in liquid, gas or solid form and blister, choke and affect the nerves or blood. Chemical warfare agents are generally classified according to their effect on the organism and can be roughly grouped as: Nerve Agents, Mustard Agents, Hydrogen Cyanide, Tear Gases, Arsines, Psychotomimetic Agents, Toxins and Potential CW Agents.

Under the Chemical Weapons Convention (CWC) chemicals are divided into three groups, defining their purpose and treatment:

* Schedule One are those typically used in weapons such as sarin and mustard gas and tabun;

* Schedule Two include those that can be used in weapons such as amiton and BZ;

* Schedule Three chemicals include the least toxic substances that can be used for research and the production of medicine, dyes, textiles, etc.

CW agents mainly used against people 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 limit between lethal and incapacitating substances is not absolute but refers to a statistical average.

Incendiary agents such as napalm and phosphorus are not considered to be CW agents since they achieve their effect mainly through thermal energy. Certain types of smoke ammunition are not classed as a chemical weapon since the poisonous effect is not the reason for their use. Plants, micro-organisms, the produced toxins belong to that class. Pathogenic micro-organisms, mainly viruses and bacteria, are classed as biological weapons.

* Chemicals that blister: sulphur mustard, lewisite, nitrogen mustard, mustard-leweisite, phosgene-oxime.

* Chemicals that affect the nerves: VX, Sarin, Soman, tabun, novichole agents.

* Chemicals that cause choking: cholrine, phosgene, diphosgene, chloropicrin.

* Chemicals that affect the blood: herygem, cynanide, cynaogen chlorine.

* Chemicals for riot control: tear agent 2 (SN gas), tear agent 0 (CS gas), psychedelic agent 3 (BZ)

  When have they been used - a short history

1863- The US War Department issues General Order 100, proclaiming "the use of poison in any manner, be it to poison wells, or foods, or arms, is wholly excluded from modern warfare".

World War I - the use of chemical agents in WWI caused an estimated 1,300,000 casualties, including 90,000 deaths.

1914- French begin using tear gas in grenades (xylyl bromide) and Germans retaliate with tear gas in artillery shells. This was the first significant use of chemical warfare in WWI. 

1915- Germans attack the French with chlorine gas at Ypres, France. This was the first effective use of chemical warfare in WWI.

1915 - British use chlorine gas against the Germans at the Battle of Loos. This was the first chemical weapons attack by the British.

1918 - Germans launch the first projectile attack against US troops with phosgene and chloropicrin shells. The first major use of gas against American forces.

1918 - Fist US use of gas in warfare.

1918 - The US begins its formal chemical weapons program with the establishment of the Chemical Warfare Service.

1919 - British use Adamsite against the Bolsheviks during the Russian Civil War.

1922-1927 - The Spanish use chemical weapons against the Rif rebels in Spanish Morocco.

1936 - Italy uses mustard gas against Ethiopians during its invasion of Abyssinia.

1942 - Nazis begin using Zyklon B (hydrocyanic acid) in gas chambers for the mass murder of concentration camp prisoners.

1943 - A US ship loaded with mustard bombs s attacked by Germans in the port of Bari, Italy.

1945 - Germans manufacture and stockpile large amounts of tabun and sarin nerve gases but do not use them.

1962-1970 - US uses treat gas and four types of defoliant, including Agent Orange, in Vietnam.

1963-1967 - Egypt uses chemical weapons (phosgene, mustard) against Yemen.

1975-1983 - Alleged use of Yellow Rain (trichothecene mycotoxins) by Soviet-backed forces in Laos and Kampuchea. There is evidence to suggest use of T-2 toxin, but an alternative hypothesis suggests that the yellow spots labelled Yellow Rain were caused by swarms of defecating bees.

1979 - The US government alleges Soviets use of chemical weapons in Afghanistan, including Yellow Rain.

1983 - Iraq begins using chemical weapons (mustard gas), in the war against Iran.

1984 - First ever use of nerve agent tabun on the battlefield, by Iraq during Iran-Iraq War.

1987-1988 - Iraq uses chemical weapons (hydrogen cyanide, mustard gas) in its Anfal Campaign against the Kurds, most notably in the Halabja Massacre of 1988.

1995 - The Tokyo Subway sarin gas attack killed nearly a dozen people and incapacitated or injured approximately 5,000 others. Thousands did not die from the Tokyo attack due to impurity of the agent. A tiny drop of sarin, which was originally developed in Germany in the 1930s, can kill within minutes after skin contact or inhalation of its vapour. Like all other nerve agents, sarin blocks the action of acetylcholinesterase, an enzyme necessary for the transmission of nerve impulses.

  Efforts to ban chemical weapons

The experience of large-scale chemical warfare was so horrifying that it led to the 1925 Geneva Protocol, which forbids the use of chemical and bacteriological agents in war. Images of victims gasping, frothing and choking to death had a profound impact. The text of the protocol reflects the global sense of abhorrence. It affirmed that these weapons had been "justly condemned by the general opinion of the civilized world."

The Chemical Weapons Convention (CWC) reinforces aspects of the Geneva Conventions that also dealt with these agents and was negotiated over a period of 24 years. In 1992, after a decade of long and painstaking negotiations, the Conference on Disarmament in Geneva agreed to the text of the CWC. It was adopted by the General Assembly on 30 November 1992, in a resolution entitled Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction (A/RES/47/39).

The CWC has 188 states parties. Israel and Myanmar have signed but not ratified the treaty; while Angola, Egypt, the Democratic People’s Republic of Korea, Somalia, South Sudan and Syria have not yet signed the treaty at all. The CWC entered into force on 29 April 1997, 180 days after Hungary, the 65th country, ratified the treaty. Countries that ratify must destroy all chemical weapons over a ten year period with the treaty providing a "levelling out principle," which ensures that possessors destroy their stockpiles at roughly the same time.

Five years after entry into force, destruction of 20% of the stockpile is to be completed. After seven years, 45% of the destruction should be complete. Under the treaty countries must stop any development, production, acquisition, stockpiling and retention of chemical weapons. The CWC requires States Parties to report the location of chemical weapons storage sites, the location and characteristics of chemical weapons production and research facilities and prohibits trade in certain chemicals with countries not party to the treaty.

The verification provisions of the CWC do not only affect the military sector but also the civilian chemical industry, world-wide, through certain restrictions and obligations regarding the production, processing and consumption of chemicals that are considered relevant to the objectives of the Convention. The Convention also contains provisions on assistance in case a State Party is attacked or threatened with attack by chemical weapons and on promoting the trade in chemicals and related equipment among State Parties.

What do individual governments have to do after they sign the CWC?

Once a government has ratified the Convention, it is required to declare all of its CW facilities (both commercial and public) within 30 days, and must destroy stockpiles within 10 years in an environmentally sound manner at its own expense. States Parties need to ensure that the prohibitions in the treaty are translated from international law, binding only on states, to Convention specifically requires States Parties to extend their obligations to private entities, it remain silent on precisely how to achieve this.

States are required to enact penal legislation, prohibiting their private citizens, no matter where they are on earth, from undertaking any of the activities prohibited to the state itself by the Convention. Many states have also enacted laws laying down an obligation to provide declaration required relating to production, processing, consumption, import and export of chemicals above thresholds specified in the Convention.

Another area in which most states have enacted legislation provides two-year, multiple-entry visa to inspectors who on 48 hours notification can inspect to clarify and resolve questions of non-compliance. During inspections they can interview personnel, request samples and evaluate chemical weapons destruction sites. They can evaluate a site for up to 84 hours.

What is the Organisation for the Prohibition of Chemical Weapons?

The Organisation for the Prohibition of Chemical Weapons (OPCW) came into existence on 29 April 1997 and is based in The Hague, Netherlands. The OPCW is made up of about 5,000 staff members that monitor the destruction of chemical weapons and of chemical weapons production facilities. The staff also implement the complex declaration and short notice challenge inspections under theverification procedures, undertake routine inspections, and trains inspectors. The staff are accountable to all signatories and an Executive Council made up of 41 member states.

  How are chemical weapons destroyed?

Previously the most common disposal methods for chemical weapons were land burial, sea dumping, detonation (firing or exploding the munitions) and open-pit burning. These methods may have been thought to be quite clever at the time (out of sight, out of mind), but their danger has since become starkly apparent.

Buried munitions pose problems environmentally. Once the munitions begin to corrode and leak, the agents can contaminate the surrounding soil and even get into water sources. Sea dumping of chemical munitions is another method of disposal that has caused a number of problems. Some of these dumping operations have occurred in relatively shallow water in the Baltic Sea and off the coast of Japan. In both of these regions, dumped chemical weapons caused serious problems for the fishing industry. Fishermen in the Baltic and off the coast of Japan still haul old chemical weapons up in their nets, and are sometimes exposed to still-active agents.

There are two major confirmed technologies for destroying chemical weapons acceptable under the CWC limits today, incineration and chemical degradation. However, there are dozens of alternative technologies, and the number is growing.

Under the Baseline incineration process, chemical weapons are first taken to the demilitarization facility, where the chemical agent is removed from the munitions or bulk containers by automated equipment. This puts the workers at the demilitarization plant at a very low risk of contamination.

Chemical degradation (or chemical neutralization) technologies also take many different forms. There are a number of chemicals, namely alkalis and oxidants, which reduce and often negate the toxicity of chemical agents.

While the technologies for destroying chemical weapons do exist, in practice there are many factors that may come into conflict when the destruction process is carried out. The issues that must be considered include the high costs of destruction and safety, as well as environmental, legal, and political factors.

Although environmentalist groups have legitimate concerns that the weapons be disposed of in an environmentally safe manner, weapons experts generally agree that it is environmentally much more dangerous for the weapons to remain in storage for the additional years required to develop alternative methods of destruction.

Safety must also be carefully considered in the destruction of chemical weapons. This entails precautions and regulations that protect not only employees working in the destruction facility, but also the civilian population surrounding the facility. Highly sensitive monitoring equipment must be used in order to ensure there is no leakage of toxic agents.

The United States claims it has 12,000 tons of chemical agents in munitions and another 19,000 tons in bulk storage. Russia, the sole in-heritor of the former Soviet Union's chemical weapon stockpile, officially reports its stockpile to be 40,000 tons. These two countries are the only signatories to the CWC that have admitted to possessing chemical weapons. In 1994, the United Nations Special Commission on Iraq (UNSCOM) declared that Iraqi chemical weapons capabilities had been destroyed, leaving Iraq with no surplus (or any) chemical weapons stocks. A large number of old and abandoned chemical weapons still exist in a number of countries. The total amount of chemical weapons and old and abandoned chemical weapons that must be destroyed worldwide is daunting.

The first deadline for the destruction of chemical weapons was in April 2007, but when discovered that the United States, Libya, and Russia would miss the deadline the countries were granted an extension of five years to April 2012. This deadline was not to be extended any further. Although even the extended deadline has been missed, the integrity of the Convention is still preserved. The countries in question have submitted detailed plans to the OPCW for the destruction of their remaining arsenals, together with planned dates of completion. Several States Parties have considered assisting Libya in the destruction of its remaining stockpile; Canada has provided large sums towards this goal under the Global Partnership Program.

Chemical weapons proliferation

One must also consider the threat of proliferation when it comes to reducing arsenals. In the case of chemical weapons, the threat of proliferation is much smaller than that of nuclear or conventional weapons. This is true for several reasons. First of all, many of the chemical weapons of today's arsenals are aging and dangerous to transport. Second, it would be cheaper in most cases for a country desiring chemical weapons to produce them than to try to buy them on the illegal arms trade market. Third, the quantity of chemical weapons needed to pose a significant threat is large, especially when compared to nuclear weapons. An illegal transfer of a significant quantity of chemical weapons would be very difficult to hide. Finally, a country would not want to import chemical weapons unless it had sufficient chemical protection gear and training for its forces, a costly undertaking. Unfortunately, virtually every country has the technology to produce some of the simple agents used during World War I. In sum, if a country really wants a chemical weapons arsenal, it would be easier to build one itself rather than to import stocks.