Sulfur mustard is a thick liquid, which was made for use as a chemical weapon. Presently, the chemical is found at a few Army facilities in large quantities and at several locations in smaller quantities. It is often called by its common name, 'mustard gas.' However, the term 'mustard gas' can be confusing, since it is stored as a liquid and is not likely to change into a vapor immediately if it is released at ordinary temperatures. As a liquid, it is colorless when pure and it is brown when mixed with other chemicals. It is odorless when pure, but can have a slight garlic smell when mixed with other chemicals. It dissolves easily in fats, oils, alcohol, and gasoline. Sulfur mustard dissolves slowly in unstirred water, but within minutes in stirred water. When it does dissolve, it reacts with water and turns into different chemicals. It was used in chemical warfare as early as World War I and as late as the Iran-Iraq War in 1980-1988. It is not used in the United States, except for laboratory testing of health effects and antidotes.
Sulfur mustard in the enviroment
Sulfur mustard is not found naturally in the environment in any amount. If sulfur mustard is accidentally spilled at an Army base where it is stored, it could be released into the environment. Currently, all of the sulfur mustard at these Army bases is being destroyed by burning or neutralization. U.S. law requires that the Department of Defense destroy all sulfur mustard by 2004. However, complete destruction of sulfur mustard may continue beyond this date. Once all of the sulfur mustard is destroyed, it will no longer be dangerous. If sulfur mustard is put on soil, it will remain there for at least a day, but may remain for several days or longer. The time it takes for sulfur mustard to disappear from soil depends on how hot it is outside and how strongly the wind is blowing. If it is hot and the wind is strong, then sulfur mustard will disappear faster. When sulfur mustard disappears from soil, it becomes a vapor or changes into other compounds if the soil is wet. If sulfur mustard is buried underground, it may not disappear for several years. Sulfur mustard will not move through soil to underground water. If sulfur mustard is put in water, it dissolves within minutes if the water is stirred, and slowly if is not. When it does dissolve, it reacts with water and changes to other compounds. The time necessary for a quantity of sulfur mustard that is dissolved in water to decrease by half is about 2 minutes at 40 °C (104 °F). If large amounts of sulfur mustard are spilled into water, most of the sulfur mustard will change to other compounds very slowly or not at all. If sulfur mustard is released into air, it will react with components in the air to form other compounds. The time necessary for a quantity of sulfur mustard in air to decrease by half is about 2 days at 25 °C (77 °F). Because sulfur mustard changes to other chemicals in the environment, it will not concentrate in plants or animals.
Exposure to Sulfur mustard
Sulfur mustard is not currently being produced in the United States. The general public might be exposed through accidental release from the Army bases where it is stored. These storage areas are heavily guarded, and storage buildings are sealed. People who work at Army bases that store sulfur mustard are more likely to be exposed than the general public. However, the Army has taken many precautions to protect the public from exposure to sulfur mustard. The general public may be exposed to sulfur mustard at hazardous waste sites that contain sulfur mustard. In addition, the use of sulfur mustard by terrorists is of concern. Persons involved in the transport or disposal of sulfur mustard may be exposed to mustard agents generated unintentionally through mishap. Spouses, children, and others may be exposed if workers unknowingly bring the mustard agents out of the factory on their skin or clothing. Sulfur mustard readily passes through ordinary clothing. Mixed in water, sulfur mustard changes its form within minutes, so it is very unlikely that you would drink it. The likelihood of the general population being exposed by way of water (drinking, cooking, bathing, and swimming) is therefore very small. Sulfur mustard does not occur naturally; therefore, there are no background levels in the soil, air, water, or food. If it is accidentally released, it will stay in the air or on the ground for 1-3 days. Under certain conditions, it may remain on the ground or in water for long periods.
Pathways for sulfur mustard in the body
Sulfur mustard can enter your body easily and quickly if it gets in your eyes or on your skin, or if you breathe sulfur mustard vapors. It can easily pass through your clothing to get onto your skin. It is possible that you could come into contact with sulfur mustard at hazardous waste sites that contain this material. Sulfur mustard changes into other chemicals in your body, and these chemicals mostly leave your body in the urine within a few weeks.
Health effects of sulfur mustard
To protect the public from the harmful effects of toxic chemicals and to find ways to treat people who have been harmed, scientists use many tests.
Sulfur mustard can harm you depending on how much of the chemical you were exposed to and for how long. Sulfur mustard may make your eyes burn, your eyelids swell, or cause you to blink a lot. Sulfur mustard may burn your skin and cause skin blisters within a few days. Your eyes and the parts of your body that are sweaty are the most likely to be harmed. If you breathe it, sulfur mustard can cause coughing, bronchitis, and long-term respiratory disease. Sulfur mustard may affect reproduction. Some men exposed to sulfur mustard during war have reported decreased sexual drive and have had problems with sexual function due to scarring of genital tissues and lower sperm counts. The International Agency for Research on Cancer has determined that sulfur mustard is carcinogenic to humans. The Department of Health and Human Services has also determined that sulfur mustard is a known carcinogen. It can cause cancer in your airways, lungs, skin, and maybe other areas of your body later in life. If you are exposed to a very large amount of sulfur mustard, you can eventually die from it. Some of the chemicals that are formed when sulfur mustard is burned or spilled into water can also be irritating to the skin.
Sulfur mustard effect on children
This section discusses potential health effects from exposures during the period from conception to maturity at 18 years of age in humans.
Sulfur mustard causes the eyes and skin of children to burn similarly to adults; however, the burns may be more severe in children. Blisters may appear sooner in children than adults, as early as 4 hours after sulfur mustard contacts the skin. Coughing and vomiting have been reported as early symptoms of exposure to sulfur mustard in children. Sulfur mustard vapors are heavier than air and since young children are closer to the ground or floor because of their height, they may be exposed to more sulfur mustard vapors than adults during accidental exposures. Sulfur mustard may cause birth defects or affect the development of children. An increased incidence of birth defects has been reported among newborn babies of sulfur mustard victims exposed during war. Studies in animals also indicate that sulfur mustard may affect development. It is not known if sulfur mustard can cross the placenta or be passed to infants in breast milk.
Reducing the risk of exposure in families
If your doctor finds that you have been exposed to significant amounts of sulfur mustard, ask whether your children might also be exposed. Your doctor might need to ask your state health department to investigate.
The risk of exposure to sulfur mustard to the general public may be slightly greater for those who live or work near Army bases and other facilities that store it. However, the Army has instituted precautions to protect the public from exposure to sulfur mustard. Sulfur mustard is currently being destroyed at these facilities, and thus the risk of exposure due to accidents is decreasing.
Medical test to determine exposure
Sulfur mustard or some of the chemicals that it makes in your body can be found by testing your urine or blood. However, a test for sulfur mustard exposure is not readily available at local physicians' offices or hospitals. A urine or blood sample may be sent to a special laboratory for testing.
Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Agency for Toxic Substances and Disease Registry. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Agency for Toxic Substances and Disease Registry should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.