Dichloroethene

Dichloroethene (DCE), also known as 1,2-dichloroethylene, is a highly volatile organic compound with the formula C2H2Cl2. There are two isomers of dichloroethene: cis-1,2-dichloroethene and trans-1,2-dichloroethene, each with distinct properties and uses. This compound is primarily used as an intermediate in the manufacture of chemicals and is also a common pollutant found in the environment, particularly in groundwater.

Properties and Isomers

Dichloroethene exists in two geometric isomers: cis-1,2-dichloroethene and trans-1,2-dichloroethene. The cis isomer has the two chlorine atoms on the same side of the double bond, while the trans isomer has them on opposite sides. The physical properties of these isomers differ slightly. For example, the cis isomer has a boiling point of 60.3°C, whereas the trans isomer boils at 47.5°C. Both isomers are colorless, flammable liquids with a slight, chloroform-like odor.

Production and Uses

Dichloroethene is produced through the chlorination of ethylene. It is mainly used as an intermediate in the production of vinyl chloride, the monomer for polyvinyl chloride (PVC) plastic. In addition to its industrial applications, dichloroethene is used as a solvent and in the manufacture of adhesives, synthetic fibers, and refrigerants.

Health Effects

Exposure to dichloroethene can occur through inhalation, ingestion, or skin contact. The health effects of exposure to this compound depend on the duration and level of exposure. Short-term exposure to high levels of dichloroethene can cause respiratory irritation, dizziness, headache, and nausea. Long-term exposure has been associated with more severe health issues, including liver damage, kidney damage, and cancer. The trans isomer is considered to be less toxic than the cis isomer.

Environmental Impact

Dichloroethene is a common environmental pollutant, especially in areas surrounding industrial sites where it is produced or used. It can enter the environment through industrial discharges, leaks, or improper disposal practices. Once in the environment, dichloroethene can contaminate air, water, and soil. It is particularly concerning as a groundwater contaminant because of its mobility and persistence. Bioremediation and other remediation techniques are used to remove or degrade dichloroethene in contaminated sites.

Regulation and Monitoring

Due to its potential health and environmental impacts, the production, use, and disposal of dichloroethene are regulated in many countries. Regulatory agencies, such as the Environmental Protection Agency (EPA) in the United States, have established guidelines and standards for dichloroethene levels in air, water, and soil. Monitoring and compliance efforts are essential to minimize the risks associated with this compound.

See Also

• Vinyl Chloride
• Polyvinyl Chloride (PVC)
• Bioremediation
• Environmental Pollution