pentachlorophenol

Pentachlorophenol (PCP) is an organochlorine compound with the formula C6HCl5O. It is a white to pale tan crystalline solid that is highly chlorinated and lipophilic. PCP is produced by chlorination of phenol under acidic or catalytic conditions. It has historically been used as a wood preservative, fungicide, and biocide to protect timber, railroad ties, utility poles, and other wood products from rot and insect attack; it has also been used as a disinfectant and pesticide in some applications.

Environmental and health aspects: PCP is persistent in the environment, tending to bind to soils and sediments. It degrades slowly and can accumulate in aquatic organisms, leading to potential ecological toxicity. It is toxic to aquatic life and can cause adverse health effects in humans through inhalation, ingestion, or dermal exposure; acute effects include irritation and dermatitis, while long-term exposure has been associated with liver and kidney effects in animals. The International Agency for Research on Cancer has classified pentachlorophenol as possibly carcinogenic to humans (Group 2B).

Regulatory status: Due to its persistence and toxicity, PCP uses have been restricted or banned in many countries. It is listed under the Stockholm Convention on Persistent Organic Pollutants, and residues persist in some older treated wood and in contaminated soils and sediments, where remediation may be required.