Facts About the Chemical Warfare Agent Lewisite

— -- Lewisite is a type of chemical warfare agent called a vesicant, or blistering agent, because it causes blistering of the skin and mucous membranes on contact.

What It Does

It is a powerful irritant and blistering agent that immediately damages the skin, eyes, and respiratory tract. Because it contains arsenic, lewisite has some effects that are similar to arsenic poisoning, including stomach ailments and low blood pressure

How Lethal Is It?

Adverse health effects caused by lewisite depend on the amount people are exposed to, the route of exposure, and the length of time people are exposed.

Forms

Lewisite is an oily, colorless liquid in its pure form but can also be released as a gas or vapor.

Symptoms of Exposure

Skin pain and irritation occur within seconds. The blister begins small, surrounded by red areas and then expands to cover the entire reddened area of skin. Eyes are irritated, swollen, and tear on contact. Other symptoms are a runny nose, sneezing, hoarseness, bloody nose, sinus pain, shortness of breath, cough, blisters, diarrhea, nausea, vomiting, low blood pressure (lewisite shock), and swollen eyes.

What It Looks Like

Industrially produced lewisite is an amber to dark brown liquid and has a strong penetrating geranium odor; the pure compound is a colorless, odorless, oily liquid.

How You Can Protect Yourself

If you think you may have been exposed, remove your clothing, rapidly wash your entire body with soap and water, and get medical care as quickly as possible. Make sure to seal your exposed clothing in a plastic bag. If you have swallowed lewisite, do not drink any fluids or induce vomiting.

How It Can Be Used

Lewisite gas can be released into the air. In its liquid form it can poison water, and be used to contaminate food.

History

Lewisite was produced in 1918 by American chemist Winford Lee Lewis. It was originally produced to be used in World War I, but its production came too late. It has been used only as a chemical warfare agent, and has no medical or practical use. It is not found naturally in the environment.