Chemical Warfare Agents

Unique identifier / Notation

CH0019

Synonyms

Not identified.

Chemical agents or ‘chemical warfare agents’ (chemical weapons) are chemicals used to cause intentional death or harm through their toxic properties. Munitions, devices and other equipment specifically designed to weaponise toxic chemicals also fall under the definition of chemical weapons. The Chemical Weapons Convention (CWC) prohibition against the use of toxic chemicals and their precursors and also covers toxins of biological origin (OPCW, 2019a,b).

Primary reference(s)

OPCW, 2019a. What is a chemical weapon? Organisation for the Prohibition of Chemical Weapons (OPCW). Accessed 1 December 2019.

OPCW, 2019b. Chemical Weapons Convention: Annex on Chemicals: Schedule 1: A: Toxic Chemicals. Organisation for the Prohibition of Chemical Weapons (OPCW) Accessed 21 August 2020.

Additional scientific description

The relevant toxic chemicals are listed in the Chemical Weapons Convention’s Annex on Chemicals (OPCW, 2019b) and, in principle, the understanding and application of a so-called General Purpose Criterion (GPC) and include:

Blistering agents: These toxic compounds act via inhalation and contact, affecting the eyes, respiratory tract, and skin, first as an irritant and then as a cell poison. Exposure to blister agents causes large and often life-threatening skin blisters which resemble severe burns, and often results in blindness and permanent damage to the respiratory system. Examples include mustard gas.
Blood agents: These agents inhibit the ability of cells to transfer and use oxygen, effectively causing the body to suffocate. Blood agents generally enter the body through inhalation and are distributed via the blood. Examples include hydrogen cyanide and cyanogen chloride.
Choking agents: Inflicting injury mainly on the respiratory tract, choking agents irritate the nose, throat, and especially the lungs. When inhaled, these agents cause alveoli (air sacs in the lungs) to secrete fluid, essentially drowning those affected. Chlorine and phosgene gas are examples.
Nerve agents: Nerve agents block impulses between nerve cells or across synapses and are highly toxic with rapid effects. They act primarily by absorption through the lungs and skin inhibiting the action of critical enzymes required for the normal functioning of the nervous system, causing seizures, loss of body control, muscle paralysis (including heart and diaphragm), and ultimately death. Sarin and VX gas are examples.

Metrics and numeric limits

None identified.

Key relevant UN convention / multilateral treaty

The General Purpose Criterion (GPC), which is embodied in the Chemical Weapons Convention’s definition of a ‘chemical weapon’, prohibits all toxic chemicals and their precursors except for non-prohibited purposes (OPCW, 2019a,b). This mechanism ensures that the Chemical Weapons Convention’s prohibitions remain comprehensive in scope, including in terms of scientific and technological developments.

Examples of drivers, outcomes and risk management

Drivers have been wars and civil wars, associated with death, injury and often life-long disabilities (Australia Group, 2018a,b).

Control measures include import-export control of relevant chemical agents and precursors (Australia Group, 2018a,b). A key factor in ensuring that toxic chemicals and their precursors are not meant to cause death or other harm (i.e., as a ‘method of warfare’) is the application of the General Purpose Criterion. A given activity or programme may be for ‘defensive’ (i.e., permitted) or ‘offensive’ (i.e., prohibited) purposes.

The intent of the activity or programme must therefore be determined. It is not always possible for governments to agree on the nature of a given activity or programme within a multilateral disarmament and arms control framework, including the Chemical Weapons Convention (Krutzsch et al., 2014).

In addition an international network of specialised analytical laboratories, able to detect potential chemical warfare agents in the environment and in exposed human bodies are likely to be of benefit (EU, 2009).