Carbon Tetrachloride - Uses

Uses

In the 20th century, carbon tetrachloride was widely used as a dry cleaning solvent, as a refrigerant, and in lava lamps.

In 1910, The Pyrene Manufacturing Company of Delaware filed a patent for a using carbon tetrachloride to extinguish fires. The liquid vaporized and extinguished the flames by inhibiting the chemical chain reaction of the combustion process (it was an early 20th-century presupposition that the fire suppression ability of carbon tetrachloride relied on oxygen removal.) In 1911, they patented a small, portable extinguisher that used the chemical. This consisted of a brass bottle with an integrated handpump that was used to expel a jet of liquid toward the fire. As the container was unpressurized, it could be easily refilled after use. Carbon tetrachloride was suitable for liquid and electrical fires and the extinguishers were often carried on aircraft or motor vehicles.

One specialty use of carbon tetrachloride was in Stamp collecting, to reveal Watermarks on postage stamps without damaging them. A small amount of the liquid was placed on the back of a stamp, sitting in a black glass or obsidian tray. The letters or design of the watermark could then be clearly seen.

However, once it became apparent that carbon tetrachloride exposure had severe adverse health effects, such as causing fulminant necrosis, safer alternatives such as tetrachloroethylene were found for these applications, and its use in these roles declined from about 1940 onward. The fact that high temperatures cause it to react to produce phosgene made it especially hazardous when used against fires. This reaction also caused a rapid depletion of oxygen. Carbon tetrachloride persisted as a pesticide to kill insects in stored grain, but, in 1970, it was banned in consumer products in the United States.

Prior to the Montreal Protocol, large quantities of carbon tetrachloride were used to produce the freon refrigerants R-11 (trichlorofluoromethane) and R-12 (dichlorodifluoromethane). However, these refrigerants play a role in ozone depletion and have been phased out. Carbon tetrachloride is still used to manufacture less destructive refrigerants. Carbon tetrachloride has also been used in the detection of neutrinos.

Carbon tetrachloride is one of the most potent hepatotoxins (toxic to the liver), and is widely used in scientific research to evaluate hepatoprotective agents.