Chlorophenol

Chlorophenol refers to a family of chemical compounds in which one or more hydrogen atoms on the phenyl ring of phenol are replaced by chlorine atoms. The simple class includes monochlorophenols (the three positional isomers: 2-chlorophenol, 3-chlorophenol, and 4-chlorophenol) and higher chlorinated derivatives such as di-, tri-, and higher chlorophenols. The properties and uses of these isomers vary with the number and position of chlorine substituents.

Chlorophenols are produced mainly by the chlorination of phenol under controlled conditions, but they also occur as byproducts in various industrial chlorination processes and can form during combustion and waste incineration. As a result, chlorophenols can be found in environmental media such as water, soil, and sediment, sometimes at trace levels.

Uses and applications vary by compound. Many chlorophenols serve as intermediates in the manufacture of dyes, pesticides, and pharmaceuticals. Pentachlorophenol, historically used as a wood preservative and disinfectant, is now regulated in many countries due to health and environmental concerns. Other polychlorinated phenols are used as precursors to agrochemicals, antiseptics, and disinfectants, but their use is often restricted because of toxicity and persistence.

Safety and environmental considerations: The toxicity of chlorophenols ranges from moderate to high depending on the compound and exposure route. They can be irritating and may pose systemic health risks at higher exposures. Many chlorophenols are persistent in the environment and can affect aquatic life, with potential for bioaccumulation. Regulatory frameworks typically restrict release, usage, and disposal and emphasize proper handling and contaminated-site remediation.