ABSTRACT
Guides for Emergency Response: Chemical Agent or Weapon: Arsenical Vesicants including Ethyldichloroarsine (ED), Methyldichloroarsine (MD), Phenyldichloroarsine (PD) Arsenical Vesicants: Such chemical agents are organic dichloroarsines. Th e main ones that could become chemical agents or weapons are ethyldichloroarsine, methyldichloroarsine, and phenyldichloroarsine. All arsenical vesicants are colorless to brown liquids, soluble in most organic solvents but poorly soluble in water. Th ey are more volatile than mustard agents and have fruity to geranium-like odors. Th ey react rapidly with water to yield the corresponding solid arsenoxides, with concurrent loss of volatility and most of their vesicant properties. As liquids, they gradually penetrate rubber and most impermeable fabrics. Arsenical vesicants are much more dangerous as liquids than as vapors. Th e liquids do cause hazardous burns on the eyes and skin, while fi eld concentrations of vapors are not likely to cause permanent signifi cant injuries. Immediate decontamination is required to remove the liquid agents in time to prevent severe burns, but decontamination is not required for vapor exposure unless there is pain to the victim. When inhaled, the vapors cause sneezing and may instill irritation of the upper respiratory tract.
