BAGHDAD, IRAQ - In an alarming escalation of violence, truck bombs containing chlorine are now being deployed in Iraq. Dozens of people have died, and hundreds were injured in several attacks since February.

On March 17, three suicide bombers driving chlorine-laden trucks struck in the Sunni province of Anbar, killing two policemen and injuring several American soldiers and hundreds of Iraqi civilians. On February 21, a truck bomb that combined explosives with chlorine gas blew up in southern Baghdad. That bomb killed at least two people and wounded 32 others, many of them sent to hospitals with respiratory problems. The detonation on February 21 of a tanker filled with chlorine that had been rigged to explode, killed nine and wounded 148, including many women and children. The first reported attack with chlorine took place on January, 28 in Anbar Province. Sixteen people were killed in that attack, when a dump truck with explosives and a chlorine tank was detonated.

Chlorine gas reacts with the moisture in mucous membranes, such as eyes and the respiratory tract, to create acid, which burns the skin, and in sufficient concentration, can destroy the respiratory system after only a few breaths.

Some historians mark the start of modern chemical warfare with the use of chlorine by Germany against French soldiers on April 22, 1915 in Ypres. The Allies soon retaliated, expanding the arsenal of poisonous gas to include phosgene and mustard gas. Thousands of soldiers died, and many more suffered from deteriorating health, including increased susceptibility to tuberculosis and early death.

After World War I, chemical weapons were used during the Russian Civil War (1918-1920); by the British in Iraq in the 1920s; by Italy during its invasion of Ethiopia (1935-36); and by Japan in its war with China (1937-42). During World War II, all the major powers possessed large stockpiles of chemical weapons, but were deterred from using them from fear of retaliation, and the weapons were not used on a significant scale.

Since World War II, chemical weapons have only been used twice: by the Egyptians during the Yemen civil war in the 60’s and by the Iraq government against the Kurds in 1988.

Chlorine is classified as an extremely hazardous substance under SARA Title III, EPA’s Risk Management Regulation, and OSHA’s Process Safety Management regulation. The Immediately Dangerous to Life and Health (IDLH) concentration is 10 parts per million. The U.S. Department of Transportation places chlorine in Class 2, Division 2.3- a poisonous gas.

More than thirteen million tons of chlorine are used in the United States every year. Chlorine is widely used in water treatment. In industry it is used as a bleach in the manufacture of paper and cloth and to make a wide variety of products. When released to the air, chlorine is a yellow-green gas that is heavier than air and has a strong irritating odor. It will react with water to form hypochlorous acid and hydrochloric acid.

Chlorine exposure is a common accidental inhalation exposure, occupationally and environmentally. Household accidents involve the inappropriate mixing of chlorine cleaning solutions with acidic agents such as ammonia. Chlorinated swimming pool agents can give off chlorine gas when involved in fire. Occupational accidents may involve sewage treatment incidents or industrial bleaching operations.

Transportation accidents involving chlorine have been deadly. In October 2006 in South Carolina, nine people were killed when a freight train slammed into a parked train on a side track in the town of Graniteville. Fourteen cars on the moving train derailed, including three chlorine tank cars, one of which leaked a cloud of the deadly gas. Besides the nine fatalities, at least 234 people were hospitalized, most with respiratory illness from inhaling chlorine gas. More than 5,000 people within a one-mile radius of the accident were evacuated from their homes. Exposure to low concentrations of chlorine gas may cause sore throat, coughing, and eye and skin irritation. Exposure to higher levels could cause burning of the eyes and skin, rapid breathing, narrowing of the bronchi, wheezing, blue coloring of the skin, accumulation of fluid in the lungs, and pain in the lung region. Exposure to even higher levels can produce severe eye and skin burns, lung collapse, and death.

If victims are exposed to chlorine, the first step is to remove them from the contaminated atmosphere. If breathing has apparently ceased, the victim should be given cardiopulmonary resuscitation immediately. If breathing has not ceased, the victim should be placed in a comfortable position and slow deep breathing should be encouraged. Oxygen should be administered as soon as possible. If liquid chlorine has contaminated the skin or clothing, the victim should be washed down with large amounts of water for fifteen minutes.

Chlorine can be found under pressure in 150 pound cylinders, but is most commonly found in storage in ton containers. Most chlorine moves in transportation in pressurized railroad tank cars.

In 2001, when Emergency Film Group updated its emergency response training film called Chlorine, it reported that the gas was “a potential terrorist weapon.” When the company was called upon to produce the training program “Using ICS in WMD Incidents” for the U.S. Department of Justice, a terrorist attack on a tank car of chlorine was the scenario on which the training was based.