[5] Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 million tonnes a year) from petroleum-derived feedstocks.

In this way, the negative charge on oxygen is delocalized on to the ortho and para carbon atoms through the pi system.

[11] An alternative explanation involves the sigma framework, postulating that the dominant effect is the induction from the more electronegative sp2 hybridised carbons; the comparatively more powerful inductive withdrawal of electron density that is provided by the sp2 system compared to an sp3 system allows for great stabilization of the oxyanion.

[13][14] Phenol exhibits keto-enol tautomerism with its unstable keto tautomer cyclohexadienone, but the effect is nearly negligible.

The equilibrium constant for enolisation is approximately 10−13, which means only one in every ten trillion molecules is in the keto form at any moment.

When a mixture of phenol and benzoyl chloride are shaken in presence of dilute sodium hydroxide solution, phenyl benzoate is formed.

Phenol and its derivatives react with iron(III) chloride to give intensely colored solutions containing phenoxide complexes.

Because of phenol's commercial importance, many methods have been developed for its production, but the cumene process is the dominant technology.

The original commercial route was developed by Bayer and Monsanto in the early 1900s, based on discoveries by Wurtz and Kekulé.

Nonionic detergents are produced by alkylation of phenol to give the alkylphenols, e.g., nonylphenol, which are then subjected to ethoxylation.

Phenol is a component in liquid–liquid phenol–chloroform extraction technique used in molecular biology for obtaining nucleic acids from tissues or cell culture samples.

[38] Concentrated phenol liquids are used for permanent treatment of ingrown toe and finger nails, a procedure known as a chemical matrixectomy.

[medical citation needed] Phenol is used as a chemical denervation agent in analgesia treatment, such as for spasticity, arthritis, or cancer pain.

[40][41] The phenol method may be used for people who did not experience pain relief from radiofrequency ablation of knee nerves.

[40][41] Phenol was discovered in 1834 by Friedlieb Ferdinand Runge, who extracted it (in impure form) from coal tar.

French chemist Auguste Laurent extracted phenol in its pure form, as a derivative of benzene, in 1841.

The skin irritation caused by continual exposure to phenol eventually led to the introduction of aseptic (germ-free) techniques in surgery.

He had his first chance on August 12, 1865, when he received a patient: an eleven-year-old boy with a tibia bone fracture which pierced the skin of his lower leg.

After setting the bone and supporting the leg with splints, he soaked clean cotton towels in undiluted carbolic acid and applied them to the wound, covered with a layer of tin foil, leaving them for four days.

Reapplying fresh bandages with diluted carbolic acid, the boy was able to walk home after about six weeks of treatment.

[49] By 16 March 1867, when the first results of Lister's work were published in the Lancet, he had treated a total of eleven patients using his new antiseptic method.

It was a remarkable achievement Phenol was the main ingredient of the "carbolic smoke ball," an ineffective device marketed in London in the 19th century as protection against influenza and other ailments, and the subject of the famous law case Carlill v Carbolic Smoke Ball Company.

Maximilian Kolbe was also murdered with a phenol injection after surviving two weeks of dehydration and starvation in Auschwitz when he volunteered to die in place of a stranger.

[62] The substance may cause harmful effects on the central nervous system and heart, resulting in dysrhythmia, seizures, and coma.

[67] Since phenol is absorbed through the skin relatively quickly, systemic poisoning can occur in addition to the local caustic burns.

[51] Resorptive poisoning by a large quantity of phenol can occur even with only a small area of skin, rapidly leading to paralysis of the central nervous system and a severe drop in body temperature.

[51] The Agency for Toxic Substances and Disease Registry (ATSDR), U.S. Department of Health and Human Services states the fatal dose for ingestion of phenol is from 1 to 32 g.[68] Chemical burns from skin exposures can be decontaminated by washing with polyethylene glycol,[69] isopropyl alcohol,[70] or perhaps even copious amounts of water.

This is particularly important if the phenol is mixed with chloroform (a commonly used mixture in molecular biology for DNA and RNA purification).

[citation needed] Phenol is also a reproductive toxin causing increased risk of miscarriage and low birth weight indicating retarded development in utero.

[8] The word phenol is also used to refer to any compound that contains a six-membered aromatic ring, bonded directly to a hydroxyl group (-OH).