Carbolic acid Poisoning

Other Names- Hydroxybenzene; Phenol; Benzenol; Phenyl alcohol


  • Carbolic acid is Colourless, prismatic, needle-like crystals that turns pink and liquefies when exposed to air.
  • It has sweetish burning taste and phenol like smell.
  • Concentrated phenol is a dark brown liquid and contains impurities like cresol.


  • It is used as Antiseptic and disinfectant.
  • It is also used for Manufacture of plastic.

Fatal dose

  • 2 gm crystals
  • 25 to 50 ml of household phenol

Fatal period

3 to 4 hours.

Absorption, metabolism and excretion

  • Phenol is absorbed from skin, gastric mucosa, per rectum, per vagina and respiratory tract.
  • Phenol is converted into hydroquinone and pyrocatechol and excreted in urine.
  • Traces are excreted by lungs, salivary glands, and skin.

Mode of action

  • Locally it acts as corrosive agent and when absorbed, it causes CNS depression, metabolic acidosis and renal failure.
  • Carbolic acid has great penetrating power and it coagulates protein.
  • There is CNS depression, metabolic acidosis, and renal damage.

Sign and symptoms

  • Burning pain followed by tingling numbness and anesthesia.
  • Nausea and vomiting.
  • Respiration is slow and labored.
  • Headache
  • Giddiness and unconsciousness
  • Convulsions
  • coma.
  • Oliguria and hepatic failure.
  • Urine become colorless
  • Ochronosis.


  • Decontaminate skin by copious washing.
  • Stomach wash can be done preferably with sodium or magnesium sulfate solution.
  • Activated charcoal in the usual manner.
  • Treatment of methaemoglobinaemia (with methylene blue).
  • Convulsions can be managed with benzodiazepines or barbiturates.
  • Supportive measure

Detection test

► Urine collected and stored in a transparent container shows a gradual change in colour to brown or green which indicates the presence of carbolic acid.

► To 10 ml of urine, add 1 ml of 10% ferric chloride. A purple or blue colour which persists even on heating indicates phenol poisoning. Gives green colour which indicates the presence of derivatives of carbolic acid i.e. cresol.

► When 10 ml of urine is boiled with Millon’s reagent, then a red colour is produced which indicates the presence of carbolic acid.

Post mortem findings

  • Corrosion of skin, at angle of mouth, chin.
  • Corrosions are initially white but turns brown in colour.
  • Splashing may be seen.
  • Tongue becomes white and swollen.
  • Mucosa of stomach is tough, white or gray, corrugated and arranged in longitudinal folds and looks leathery.
  • Mucous membrane of mouth, throat, lips are sodden whitened or ash gray .
  • Urine on exposure to air turns green.

Medicolegal aspects

  • Accidental poisoning.
  • Suicidal ingestion.
  • Homicide is not possible.
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