The Lewis structure of C2Cl4 includes a double-bonded, two-carbon chain with two chlorine atoms attached to each carbon atom. At each end, the chlorine atoms are spaced approximately 120 degrees from each other and from the carbon atom.
C2Cl4 is tetrachloroethylne using the systematic naming system, but its common name is perchlorethylene. Perchloroethylene is a common dry cleaning solvent. As shown in its Lewis structure, it is nonpolar, making it an ideal solvent for many other nonpolar organic materials. The fact that it is nonflammable and highly stable makes it a preferred compound for use by dry cleaners. The solvent works on oils and greases, making it popular for cleaning metals.
C2Cl4 dissolves fats in human tissues. It removes the fats from the skin, causing drying and irritation. It is readily absorbed through the lungs. The health concerns with C2Cl4 have led many dry cleaners to seek a safer solvent for their uses. The EPA classifies tetrachloroethylne as a likely carcinogen. It is a respiratory irritant and causes reproductive issues. Long-term exposure to individuals working in the dry cleaning industry may lead to problems with cognitive and motor skills. When released into the atmosphere in the Northern Hemisphere, most C2Cl4 remains in the air and its degradation requires up to 5 months.