Chemical Weapons Convention - Controlled Substances

Controlled Substances

The convention distinguishes three classes of controlled substance, chemicals which 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. Each class is split into Part A, which are chemicals that can be used directly as weapons, and Part B which are chemicals useful in the manufacture of chemical weapons.

• Schedule 1 chemicals have few, or no uses outside of chemical weapons. These may be produced or used for research, medical, pharmaceutical or chemical weapon defence testing purposes but production above 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 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 minute quantities of nitrogen mustard are used to treat certain cancers.

• Schedule 2 chemicals have legitimate small-scale applications. Manufacture must be declared and there are restrictions on export to countries which 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 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, which has been used as a chemical weapon but which is also a precursor in the manufacture of many legitimate organic compounds, and triethanolamine, used in the manufacture of nitrogen mustard but also commonly used in toiletries and detergents.

The treaty also deals with carbon compounds called in the treaty Discrete organic chemicals. 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.