Lewisite characteristics

Appearance and Odor Pure Lewisite is a colorless oily liquid. War gas is amber to dark brown liquid. A characteristic odor is usually geranium-like very little odor when pure. 

Lewisite is reported to possess a characteristic (geraniumlike) odor in the range of 0.8 mg/m to more commonly cited 14-23 mg/m median detection (Pechura and Rail, 1993). US forces have detectors for lewisite-paper and kits (M7 and M9A). Other forensic techniques for soil and material analysis already exists (e.g. gas chromatography). In biological tissues, increased arsenic levels are a surrogate for lewisite (Haddad and Wincester, 1983). 

Pure Lewisite is an oily, colorless liquid, and impure Lewisite is amber to black in color. It has a characteristic odor of geraniums. Lewisite is much more volatile and persistent in colder climates than mustard. Lewisite remains fluid at lower temperatures, which makes it perfect for winter dispersal. Lewisite hydrolyzes rapidly, and, on a humid day, maintaining a biologically active concentration of vapor may be difficult (U.S. Department of Defense, 1990). 

Weapons-grade lewisite consists of lewisite I, (CHC1-CH)AsC12 (90%) and lewisite II, (CHC1-CH)2AsC1 ( 10%), with very small amounts of the non-vesicant lewisite III, (CHCl-CH As (which imparts the characteristic geranium-like odour). Biomedical sample analysis has been directed only at products derived from lewisite I. 

A. General. Vesicants can penetrate the skin by contact with either liquid or vapor. The latent period is characteristic of the agent. For mustards it is usually several hours, for Lewisite it is short, and for oximes it is negligible. The latent period is also affected by the dose, temperature,... 

Fig. 4-2. Agent vaporization increases in proportion to energy sources such as heat from explosive charges or from ambient heat (as measured by air or surface temperatures). Vapor persistence is then determined by weather factors such as wind and humidity. Hydrolysis rates are affected by factors such as temperature and solubility. Agents show characteristic hydrolysis rates in water, and water vapor, as described by humidity, may cause significant hydrolysis of vaporized agent. The vesicant Lewisite, for example, shows relatively rapid hydrolysis in water vapor, while the nerve agent VX is more resistant to hydrolysis.

Note Waste composition includes other organics, such as carbon tetrachloride 1,1 dichloroethylene tetrachloroethylene trichloroethylene and vinyl chloride. Waste composition also includes toxic characteristic metals, such as arsenic, barium, cadmium, chromium, lead, mercury, nickel (not a TCLP constituent, but listed in Appendix VIII—Hazardous Constituents in 40 CFR 261), selenium, and silver. All metals may not be present in all wastes. Lewisite contains arsenic. 

Figure 2.4 provides the structures and chemical names of selected blister agents and Table 2.4 lists the chemical and physical properties of blister agents. All blister agents are liquids at 20°C, with characteristic odors. The mustards are colorless to amber-colored, and lewisite ranges from a clear to brown liquid. HD, HN-3, and L are lower in VP than HN-1 and HN-2. The vapor density of each of the blister agents is heavier than air. 

Some examples of blister agents are Lewisite, an organo-arsenic compound Sulfur Mustard, also known as Mustard Gas, a family of sulfur-based agents Nitrogen Mustard, a family of agents with similar characteristics to the Sulfur Mustards, but nitrogen based and Phosgene Oxime, a... 

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