Carbon tetrachloride, a volatile carcinogenic solvent, has been used in industrial chemical production and as a dry cleaning ingredient. Carbon tetrachloride is no longer permitted in products intended for home use in the United States.
In the past, it was widely used as a dry cleaning ingredient, fire extinguishing chemical, pesticide and chemical intermediate for manufacturing refrigerants. Carbon tetrachloride does not break down easily and can remain in groundwater for years. In addition to increasing cancer risk, carbon tetrachloride harms the liver and causes central nervous system depression, irregular heart rate, and kidney damage. Maternal exposure to carbon tetrachloride in drinking water has been associated with a risk of birth defects.
Use of carbon tetrachloride has dropped significantly since the 1980s, due to environmental concerns regarding its role in ozone depletion.
Most carbon tetrachloride arrives in the atmosphere, where it degrades very slowly, with a half-life of 18-80 years. It can be released into the environment through industrial wastewater, and has been found in significant amounts in water supplies in the United States.
Health Impact of Carbon Tetrachloride
Exposure to carbon tetrachloride can have effects on the kidney and liver, and neurological effects, including nausea, depression, indigestion and narcosis. Long term exposure can lead to liver problems and an increased risk of cancer, according to the EPA: "Some people who drink water containing carbon tetrachloride in excess of the maximum contaminant level [0.005 milligrams per Liter] over many years could experience problems with their liver and may have an increased risk of getting cancer."
Carbon tetrachloride is classified by the International Agency for Research on Cancer as being “possibly carcinogenic” to humans. It is a known animal carcinogen, but evidence in humans remains inconclusive.