Agent Name


CAS Number




Major Category

Toxic Gases & Vapors


(2-Chloroethenyl)arsonous dichloride; 1-Chloro-2-di-chloroarsinoethane; 2-Chlorovinyldichloroarsine; Arsine, (2-chlorovinyl)dichloro-; Chlorovinyl dichloroarsine; Chlorovinylarsine dichloride; Dichloro(2-chlorovinyl)arsine; Lewisite (L-1); Lewisite (arsenic compound); Lewisite 1; beta-Chlorovinylbichloroarsine; beta-Chlorovinyldichloroarsine; Arsonous dichloride, (2-chloroethenyl)-; Arsonous dichloride, As-(2-chloroethenyl)-; [ChemIDplus] UN2810


Chemical Weapons


Pure: Colorless odorless liquid; Impure: Brown with an odor like geraniums; [U.S. Army ECBC MSDS]


Chemical warfare;


Like mustard, it damages the eyes, skin, and lungs; however, Lewisite causes immediate pain; it causes redness in 15-30 minutes and blisters within several hours after exposure to the liquid. Unlike mustard, it does not cause immunosuppression. British anti-Lewisite (BAL) is an antidote if used soon after exposure. Lewisite is extremely irritating to the eyes and respiratory tract. High doses can cause pulmonary edema. It can cause hypotension and shock. It may cause hemolytic anemia. [] Lewisite can injure capillaries leading to extravasation of fluid, hypovolemia, and shock. Blood tests may show leukocytosis and the chest x-ray pulmonary edema. [Weinstein, p. 138] Contact with skin or eyes causes immediate pain and lachrymation, with maximum effects at 4-8 hours post-exposure; Vapor exposure (60-330 mg/m3) causes skin discoloration and blistering with maximum effects at 36-48 hours post-exposure; Concentrations of 10 mg/m3/15min causes inflammation of eyes and swelling of eyelids; Inhalation of 500 mg/m3/5min is potentially lethal; Severe exposure may cause pulmonary edema, respiratory failure, liver necrosis, arsenic poisoning, and blindness; [HSDB] See "Arsenic" and the linked occupational diseases.

Reference Link

ATSDR - Medical Management: Blister Agents: Lewisite (L) and Mustard-Lewisite Mixture (HL)

Exposure Assessment


Vapor Pressure

0.35 mm Hg

Lethal Concentration

LCLo (human) = 6 ppm/30min

Explanatory Notes

TIH when used as a weapon; [ERG 2012]

Adverse Effects


Toxic Pneumonitis



Skin Burns

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap
Other Information

No other related information on this agent was found.