Blister agents, also known as vesicants, are toxic substances that cause wounds to the skin and mucous membranes, the tissues that line body cavities such as the mouth and nose. Blister agents literally induce blisters within a few hours from the time they come into contact with living tissue. They also cause damage to the eyes, respiratory system, and internal organs.
The chemical name of mustard gas is sulfur mustard. In the military, it is abbreviated H, HD, and HT. Mustard gas smells like mustard or garlic. It can exist as a gas, liquid, or solid. It can be clear to yellow-brown when in liquid or solid form.
Mustard gas burns and blisters any tissue it touches, including any exposed skin and the interior surfaces of the lungs. It is extremely lethal. Only 10 mg in the lungs is required to kill a person. It irritates the eyes and throats of its victims and causes blisters to form on their skin. At times it causes prolonged blindness, vomitting, and nausea that lasts for months. Death may result from damage to the respiratory system.
Sulfur mustard damages the DNA of cells in the body, leading to respiratory cancer. It is a carcinogen (cancer-causing substance) in the human body. It is known to suppress the immune system. Although there is no antidote for sulfur mustard, exposure is not usually fatal. The military effect was to incapacitate enemy soliders. Gas masks were largely ineffective since they were not protected from absorption through the skin.
In addition, mustard gas contaminates the soil when it is released, so affected areas must be cleaned before civilians can walk on top of it again. Sulfur mustard breaks down quickly, however, in a matter of minutes to days depending on environmental conditions.
Germans introduced mustard gas during World War I. As a result of mustard gas injuries, Basil H. Liddel Hart, the British military commander, was taken out of command. The British deployed their first mustard gas weapon in 1918. It was dispersed as an aerosol in a mixture with other chemicals, which gave it a yellow-brown color and distinct odor. It caused fatalities in only 1% of all cases.
Lewisite is designated "L" in the military. Produced by the United States during World War I, Lewisite is a byproduct of a search for synthetic rubber. It is more lethal than mustard gas. Lewisite is a dark, oily liquid with a small odor resembling that of geraniums. People can be exposed through skin contact, eye contact, inhalation, or ingestion. Lewisite remains in liquid state under a wide range of conditions. Because it can stay a liquid in temperatures from below freezing to very high, it can persist for a long time.
Lewisite can easily penetrate ordinary clothing and rubber.
It causes severe eye damage within 15 minutes and blistering within 8 hours, accompanied by low blood pressure, lung swelling, and defecation. High exposure can cause death in 10 minutes, while exposure to low concentrations of lewisite can cause symptoms to appear in 30 minutes. The regular symptoms of blister agents also occur.
The name of the antidote for Lewisite is BAL (British Anti-Lewisite). It is most useful if given soon after exposure.
Lewisite is name after the American chemist Winford Lee Lewis. In 1918, Lewis discovered the thesis of Julius Nieuwland at Maloney Hall chemical laboratory in Washington, D.C., in which Nieuwland detailed the synthesis of lewisite by combination of acetylene and arsenic trichloride. It was discovered too late to be used during World War I, but it continued to be experimented with in the 1920's as the "Dew of Death."
In the 1950's, the United States declared Lewisite obselete. Stockpiles of Lewisite were neutralized with bleach and dumped into the Gulf of Mexico.
Chapter 34, p161.