Mustard gas

Mustard gas is a type of chemical weapon used commonly in warfare. It has the ability to create large blister on the exposed skin and in the lungs. When the gas is purified, it is odorless and colorless. On the other hand, when it is impure, mustard gas is usually a yellow-brown color and smells like garlic, onions, or mustard plants. Despite the name mustard gas, is is not gas but a thick, volatile liquid.

Properties
When mustard gas is in its pure state, it has no color and almost no odor. When the temperature is low, mustard gas is in the form of a liquid and is very stable during storage. In order to use mustard gas, it is mixed with other agents and is utilized in to a gaseous form. Some of the agents that is mixed with are lewisite and polymers. This gas can easily be dissolved in most organic solvents but does not mix well with water. Mustard gas is heavier than water, and is highly soluble in fats. When it is mixed with other liquids the decomposition process is slow. Mustard gas has a melting point of 13 to 14°C and boiling point 215 to 217°C. The vapour pressure is at 0°C is 0.025 mm and at 30°C it is 0.090 mm. Mustard gas vapour is extremely potent. It penetrates wood, paint, cloth, and leather. Since mustard gas is heavier than water, it sinks to the bottom of lakes, oceans, and streams and remains in the water as a local source of poison for a long period of time. When in contact with sea water turns mustard gas from liquid into a thick liquid or even a solid form. It is said that large quantities are still lying on the bottom of the Baltic Sea where they were dumped over 70 years ago.

Occurrences
Mustard Gas never occurs naturally so it is man made. It was developed as early as 1822 by César-Mansuète Despretz (1798–1863). Despretez never made any mention that mustard gas had any irritating properties. Another French chemist, Alfred Riche (1829 – 1908), worked on developing this gas in 1854 and also did not describe any adverse physical properties. In 1860, a British scientist named Frederick Guthrie developed a mustard gas compound and did note its irritating effect. In 1866, a chemist named, Albert Niemann, did similar experiments to Guthrie and recorded that the properties of mustard gas had blister-forming properties. In 1886, Viktor Meyer worked with mustard gas and described a synthesis process. He combined 2-chloroethanol with aqueous potassium sulfide, and then treated the resulting thiodiglycol with phosphorus trichloride. He created a very strong, pure compound that had much more serious effects when the skin was exposed. He tested this compounded on laboratory rabbits, and most of them died. In an English chemist named Hans Thacher Clarke replaced the phosphorus trichloride with hydrochloric acid, broke a flask while he was working with it and spent two months in the hospital for sever burns. This information was leaked to the German army and gave them the idea to use mustard gas as a chemical weapon.

Uses
Mustard gas was first used as a weapon by the Germans in World War 1. During World War 1, chemical weapons were used to injure and kill enemy soldiers. Mustard gas is a slow moving or static gas clouds which is invisible. It causes the victim to have symptoms which are extremely painful and slow acting. By using this gas, many soldiers would become incapable of performing their duties, therefore making the army weaker and less powerful. It was first used against the British Army in September 1917, and later against the French Second Army. Since it was one of the most powerful and lethal poisonous chemicals, it was commonly used during the war. The widespread use of mustard gas during war time gave rise to the view that World War 1 was "the chemists' war". Mustard gas has also been used for land mines, rockets, artillery shells, mortar rounds, and aerial bombs. The effects of using mustard gas were overwhelming. When the Germans used this agent against the British, 2934 people were admitted to the medical units during the first week that it was used. Before that time, they have been treating about 300 people a week for inhalation of chemical gases. In only the first three weeks of mustard gas use, 14,296 soldiers suffered severe injuries. The mustard gas that was not used in warfare was dumped into the various seas and oceans of the world. Much of it was found between 1966 and 2002 in the Baltic Sea. This gas contains sulfur mustard mixed with a thickener and lumps form which contain the active sulfur mustard for many years. When found by fishermen and brought up to the surface by fishing nets or by hand this gas can be dangerous to the fishermen many years after it was dumped. Artillery shells from World War 1, containing mustard gas, can still be found in France and Belgium. In 1972, the U.S. Congress banned the practice of dumping chemical weapons into the waters surrounding the United States. Many other countries followed suit. This gas was still used by Iraq in the 1970's and 1980's in their war with Iran. Mustard gas lost its popularity for use as a chemical weapon in the 1990's.

Symptoms of Exposure
Mustard gas has extremely powerful effects on its victims. In the form of gas or liquid mustard gas can attack the skin, lungs, eyes, and stomach of the victim. Internal organs can also be injured. This gas has a delayed effect and no immediate symptoms will develop. It takes anywhere from two hours to twenty-four hours for the person to be aware of what has happened and for the pain to develop. By that time, cell damage has already occurred. It is also strongly mutagenic and carcinogenic. Most people who were exposed to the gas did not suffer immediate symptoms. The victims could receive high doses of this gas without even realizing it. Within 24 hours of exposure, victims had intense itching and irritation of their skin. These areas gradually turned into large, painful blisters that filled with yellow fluid. These were severe chemical burns. The mustard gas penetrated the clothing of the individuals so it was not only the exposed skin that would burn. If the person's eyes came in contact with the gas, first the person would feel as if there was sand in their eyes. Then their eyes would get puffy and red and the person would suffer from temporary blindness. If inhaled, mustard gas caused bleeding and blistering in the mucous membranes of the respiratory system and bleeding and blistering would occur. This sometimes caused pulmonary edema. Depending on the level of contamination mustard gas could cause between first and second degree burns. Occasionally the burns could be as severe as third degree. Severe burns (over 50% of the victim's skin has been burned) are often fatal. Those that were exposed to mild or moderate amounts of mustard gas usually did not die but remained in pain and needed to rest for long periods of time. All of these individuals faced a greater risk of developing cancer later in life. Gas masks were often used to try to lesson the effects of mustard gas exposure. They only provided a small amount of protection. A man wearing a mask could still suffer from serious burns if their skin was exposed to the gas. The uniforms of the soldiers carried this gas on the surface of the cloth and could contaminate others who came into contact with the soldiers.