A number of international frameworks, such as the Chemical Weapons Convention (CWC), the Australia Group (AG), and the Wassenaar Arrangement, contribute a coordinated multilateral effort to stem the proliferation of chemical weapons (CW). To serve their purpose, these frameworks contain lists of chemicals that can be employed as chemical warfare agents, i.e. the toxic chemicals on which chemical weapons are based, or precursors for their synthesis. Moreover, the World Customs Organization (WCO) maintains a document in which it compiles many of the chemicals in these international frameworks. Some of these lists are a compilation of exact structures, where each chemical is individually enumerated. Other lists comprise both exact structures as well as families of chemicals identified by a common scaffold with variable substituents.

We are manually curating above-mentioned lists for the control of chemical warfare agents and precursors, annotating them with chemical structures (exact structures for individual chemicals and Markush structures for families of chemicals) as well as simplified molecular-input line-entry system (SMILES) notations. We are also annotating the tables with information that highlights the overlaps within the various lists, noting for each entry of each list whether that chemical is covered by one or more additional lists, either as an individual chemical or as a member of a family of chemicals. Importantly, to further highlight overlaps and differences between the lists, we also provide a synoptic table in which all the lists are provided side-by-side on one page.

It is worth emphasizing that the purpose of these lists is to support efforts to control CW proliferation. None of these lists should be construed as an exhaustive compilation of chemical warfare agents and precursors. Indeed, the CWC includes in its definition of chemical weapons  “any chemical (emphasis added) which through its chemical action on life processes can cause death, temporary incapacitation or permanent harm to humans or animals.” Hence, any weapon designed to bring about death, temporary incapacitation, or permanent harm through the toxic properties of chemicals is to be considered a chemical weapon, and any toxic chemical at the basis of such weapons is to be considered a chemical warfare agent.