This chapter includes four indices: the Alphabetical index, the Chemical Abstract Service (CAS) numbers index, the International Classification of Diseases, 10th Revision (ICD-10) numbers index, and theOrganization for theProhibitionofChemicalWeapons key (OPCW) numbers index. OPCWnumbers are found in the “Handbook on Chemicals, version 2002,” Appendix 2 in Declaration Handbook 2002 for the Convention on the Prohibition of the Development, Production, Stockpiling, and Use of Chemical Weapons and on their Destruction. OPCW numbers were developed to provide an easy method for tracking chemical warfare agents and precursors if CAS numbers were not available. Each of these indices is in alphanumeric order and entries are cross-referenced to inform-

ation about the specific agent through the handbook number. The first two digits of the handbook number following the “C” indicate the class of agent. The classes appear in order from Chapter 1 through Chapter 20 as the first 20 chapters of this handbook. They provide general information about each subgroup of agents. The letter following the hyphen (e.g., C01-A) indicates that thematerial is primarily used as an agent (A), component or precursor in the manufacture of that class of agents (C), or is a significant decomposition product or impurity of that class of agents (D). The three digits that follow the letter indicate the specific agent in the order that it appears in this handbook (e.g., C01-A001). These numbers proceed sequentially in each chapter. Materials that are not individually detailed in this handbook, typically due to the absence of published chemical or toxicological information, are only cross-referenced to the appropriate class. These materials do not have numbers after the letter following the hyphen (e.g., C01-A). The list of synonyms included in the Alphabetical index is by no means exhaustive.

Although it contains a large number of formal chemical and biological names, it primarily contains historical names, military code names, and commonnames for the agents, precursors, components, and degradation products included in this handbook. In some instances, names that have been popularized in the media but have no other historical connection to the agent have been included. Some synonyms in the Alphabetical index are followed by bracketed notations. These

notations provide additional clarifying information about the entry such as composition, modifications to the agents (e.g., thickened, dusty, binary), or a note for historical context. For example, “White Star” was a gas blend that was employed by the British in WorldWar I consisting of 50% phosgene and 50% chlorine. The entry appears as: White Star (British WWI Cylinder Gas) {Phosgene (50%) and Chlorine (50%) Mixture}