These agents are alkyl phosphonofluoridates, alkyl phosphoramidocyanidates, and alkyl phosphonofluoridothiates. They are second generation chemical warfare agents. The original agents in this series-tabun (C01-A001), sarin (C01-A002), and soman (C01A003)—were developed by German scientists during the 1930s. Both tabun and sarin were stockpiled by Nazi Germany during World War II but were never used. Since the end of World War II, modern weapons researchers have evaluated numerous other variations of the basic phosphonofluoridate and phosphoramidocyanidate structures. Although Gseries agents have been stockpiled bymost countries that havepursued a chemicalweapons program, they have been used only a limited number of times on the battlefield. They have also been used by terrorists as a mass casualty agent. The majority of G-series agents are listed in Schedule 1 of the Chemical Weapons

Convention (CWC) as long as they are within the following limitations:

O-Alkyl (less than or equal to C10, including cycloalkyl) alkyl (methyl, ethyl, propyl, or isopropyl) phosphonofluoridates, or

O-Alkyl (less than or equal to C10, including cycloalkyl)N,N-dialkyl (methyl, ethyl, propyl, or isopropyl) phosphoramidocyanidates.