Phenol is the simplest member of a class of organic compounds. It has broad biocidal properties, and dilute aqueous solutions have long been used as an antiseptic. At higher concentrations phenol causes severe skin burns. It is a violent systemic poison.

Until World War I phenol was essentially a natural coal tar product. However, synthetic methods have replaced extraction from natural sources. There are many possible syntheses.

Phenol is one of the most versatile and important industrial organic chemicals. It is the starting point for many diverse products in the home and industry. A partial list includes: nylon, epoxy resins, surface active agents, synthetic detergents, plastisizers, antioxidants, lube oil additives, phenolic resins (with formaldehyde, furfural and so on), polyurethanes, aspirin, dyes, wood preservatives, herbicides, drugs, fungicides, gasoline additives, inhibitors, explosives, and pesticides.

As carbolic acid, phenol is used in shaving creams and hand lotions. Ingestion of even small amounts may cause nausea, vomiting, and circulatory collapse, paralysis, convulsions, coma and greenish urine as well as necrosis of the mouth and GI tract. Death results from respiratory failure. Fatalities have been reported from ingestion of as little as 1.5 grams. Fatal poisoning can occur through skin absorption. A concentration of 1% is used to prevent itching from insect bites and sunburns, applied for several hours, caused gangrene resulting from spasm of small blood vessels under the skin. Swelling, pimples, rashes, hives and other skin reactions following application to the skin have beed widely reported.