Chemical weapons come in liquid, gas or solid form and blister, choke and/or affect the nerves or blood.
Around 70 different chemicals were used or stockpiled as Chemical Weapons (CW) agents during the 20th century. Examples:
- 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 agent2 (SN gas), tear agent0 (CS gas), psychedelic agent 3 (BZ)
As with biological weapons, chemical weapons in their crudest form can be produced from easily accessible materials. Therefore it is hard, if not impossible, to monitor or accurately assess which state or non-state actors have these stockpiled or in production. However, two of the largest known military stockpiles of chemical weapons are in the USA and Russia.
The Chemical Weapons Convention (CWC) reinforces the 1925 Geneva Protocol which forbade the use of chemical and bacteriological agents in war. The CWC was adopted in 1992 and entered into force in 1997, and more than 170 countries have signed it, with 139 ratifying it.
- background on chemical weapons from Reaching Critical Will
- United Nations: text of the Chemical Weapons Convention
- World Health Organisation: WHO guidance (2004) Public health response to biological and chemical weapons
- Federation of American Scientists: Introduction to Chemical Weapons