The majority of these materials are halo or cyano organoarsines. Under normal battleﬁeld conditions, they do not pose a serious danger to the life of an exposed individual and do not produce any permanent injury. Although the only agent in this class that is speciﬁcally banned under the Chemical Weapons Convention is lewisite 2 (C14-A004), which is listed in Schedule 1 because it can be readily converted into lewisite 1 (C04-A002), the use of all the other vomiting/sternatory agents is banned during a war under the general purpose criterion of the convention. They may still be used by law enforcement and the military during operations other than war such as when responding to incidents of civil unrest or to disband unruly crowds. However, because of their toxicity, this class of agents has been abandoned for other riot control agents (see Chapter 13). Vomiting/sternatory agents are ﬁrst generation chemical warfare agents employed in
World War I in an attempt to defeat the existing mask ﬁlters. Toward the end of the war, adamsite (C14-A003) was developed, produced, and weaponized but never used. It was ﬁrst used when the British dropped thermal generators containing a mixture of adamsite and diphenylchloroarsine (C14-A001) from aircraft during the Russian Civil War. This was the ﬁrst reported deployment of air delivered chemical munitions. These agents are moderately difﬁcult to synthesize. They are relatively easy to disperse
as thermally generated aerosols or as aerosolized solutions.