What molecule am I?
Readers of a certain age can remember when “carbon tet” was the go-to household solvent that easily removed organic residues such as adhesives and oils from almost any surface. It was also a widely used dry-cleaning solvent, refrigerant, and fire suppressant.
During the 1970s and ’80s, however, toxicologists discovered that inhalation of or skin contact with carbon tetrachloride (CCl4) can damage many organs, including the liver, kidneys, and central nervous system (see hazard table). CCl4 is also a “greenhouse gas” that, according to the 1995 Montreal Protocol, depletes ozone in the Earth’s stratosphere. Consequently, production and use have been significantly reduced.
In its heyday, CCl4 was produced by chlorinating C1 compounds such as chloroform, carbon disulfide, and, in later years, methane. What little is available today is a coproduct from the manufacture of chloroform and dichloromethane; however, US production is still 15 times the amount called for in the Montreal Protocol.
The CCl4 currently produced is used as a feedstock for ozone-safe refrigerants and in some minor agricultural and industrial processes. In a recent draft risk assessment of CCl4 standards under the Toxic Substances Control Act, the US Environmental Protection Agency reports that the compound is safe to use in manufacturing plants if workers wear appropriate personal protective equipment. The assessment is scheduled to be finalized by June.
Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.