The "Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction", now widely referred to as the " Chemical Weapons Convention " ( " the Convention " ), is an international treaty which aims to prohibit the development, production, acquisition, stockpiling, retention, transfer and use of chemical weapons. The Convention defines "chemical weapons" as any toxic chemicals and their precursors (except intended for purposes not prohibited under the Convention), munitions and devices specifically designed to cause death or other harm through the toxic properties of toxic chemicals, and any equipment specifically designed for use directly in connection with the employment of these munitions and devices.

So far, 193 countries are State Parties to the Chemical Weapons Convention. The Convention requires State Parties to undertake to observe the following general obligations:

• never to develop, produce, otherwise acquire, stockpile or retain chemical weapons, or transfer directly or indirectly, chemical weapons to anyone;

• never to use any chemical weapons;

• never to engage in any military preparation to use chemical weapons ;

• never to assist, encourage, or induce anyone to engage in any activity prohibited to a State Party under the Convention;

• to destroy chemical weapons it owns or possesses or that are located in any place under its jurisdiction or control ;

• to destroy all chemical weapons it abandoned on the territory of another State Party; and

• to destroy any chemical weapons production facilities it owns or possesses or that are located in any place under its jurisdiction or control; and not to use riot control agents as a method of warfare.

The Convention came into force on 29 April 1997. The People's Republic of China (PRC) is a signatory to the Convention. Signatories to the Convention have to implement the requirements of the Convention in any place under its jurisdiction. The Central People's Government of the PRC has therefore extended the application of the Convention to the Hong Kong Special Administrative Region under Article 153 of the Basic Law.