2-Chloroethanol


2-Chloroethanol is a chemical compound with the formula HOCH2CH2Cl and the simplest chlorohydrin. This colorless liquid has a pleasant ether-like odor. It is miscible with water. The molecule is bifunctional, consisting of both an alkyl chloride and an alcohol functional groups.

Synthesis and applications

2-Chloroethanol is produced by treating ethylene with hypochlorous acid:
2-Chloroethanol was once produced on a large scale as a precursor to ethylene oxide:
This application has been supplanted by the more economic direct oxidation of ethylene. Otherwise chloroethanol is still used in a number of specialized applications. Several dyes are prepared by the alkylation of aniline derivatives with chloroethanol. It is a building block in the production of pharmaceuticals, biocides and plasticizers. It is also used for manufacture of thiodiglycol. It is a solvent for cellulose acetate and ethyl cellulose, textile printing dyes, in dewaxing, refining of rosin, extraction of pine lignin, and the cleaning of machines.

Environmental aspects

Chloroethanol is a metabolite in the degradation of 1,2-dichloroethane. The alcohol is then further oxidized via chloroacetaldehyde to chloroacetate. This metabolic pathway is topical since billions of kilograms of 1,2-dichloroethane are processed annually as a precursor to vinyl chloride.

Safety

2-Chloroethanol is toxic with an of 89 mg/kg in rats. Like most organochlorine compounds, chloroethanol combusts to yield hydrogen chloride and phosgene.
In regards to dermal exposure to 2-chloroethanol, the Occupational Safety and Health Administration has set a permissible exposure limit of 5ppm over an eight-hour time-weighted average, while the National Institute for Occupational Safety and Health has a more protective recommended exposure limit of a 1ppm exposure ceiling.
It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act, and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.