Toxicity of Chlorine Gas

When we think of chlorine, we automatically think of that pungent odor around swimming pools. While chlorine is indeed used as a disinfectant in swimming pools, and in water treatment facilities, it is also a necessary part of life. The human body needs chlorine in its ionic form of chloride. Chloride is part of table salt and other chemical compounds as well. The gaseous form is what gives it that familiar odor. The gas is also very toxic. The element chlorine was discovered back in 1774, but wasn't actually given the name of chlorine until 1810.

Because of its toxicity, chlorine gas was used by the Germans in World War I as a weapon. Soon, all sides employed it as a chemical weapon. As a natural element, chlorine is found in nature as part of a salt or dissolved in the oceans, especially in very salty water bodies like the Dead Sea or the Great Salt Lake in Utah.

As a gas, chlorine is greenish yellow color with a bleach-like odor. It's heavier than air, so tends to stay low to the ground unless there is a breeze to carry it further or upward into the atmosphere. Chlorine spills are highly dangerous because if the gas is carried on the wind, it could reach large populations quickly and there's little anyone can do at that point except evacuate the people in its path. Chlorine is also somewhat water soluble and produces two acids when dissolved; hydrochloric acid (HCl) and hypochlorous acid (HclO). Since chlorine is used at a lot of water treatment facilities, sometimes workers may become exposed to the gas, or a spill could occur during transport of the gas cylinders to the plant.

Exposure can occur by breathing in the gas or by contact with the skin or eyes. Because chlorine is potent and corrosive, it can immediately burn the skin or eyes and an exposed person should rinse their skin right away. If a person inhales the gas, the effects are quick, usually within a few seconds. A low dose will cause a person to have throat irritation and they will start coughing, but higher doses, the person will begin having trouble breathing and their lungs will be affected and damaged. Children could be affected even worse than adults because their lungs in relation to their body size have a bigger surface area, therefore, they can be exposed to the same amount of chlorine gas, but end up with receiving a larger dose. Unfortunately, there's not too much that can be done for chlorine gas exposure except for treating the injured person with oxygen to keep them alive. Only in very severe cases is the exposed person likely to die. Most people who receive treatment can recover, but they must be monitored to make sure they don't have any delayed reactions.