Hydrochloric Acid is a colorless, pungent, fuming liquid. It is also known as Acidum SalisMuriatic Acid, and Spirit of salts. It is a natural constituent of stomach secretions. 

This article consists of signs and symptoms of Hydrochloric Acid Poisoning, diagnosis, fatal dose, fatal period, PM appearances, tests, and medico-legal importance. 

The management depends on the extent of injury caused by Hydrochloric Acid. It is used in dyeing industries, used as laboratory reagents, etc. 

Signs and Symptoms of Hydrochloric Acid Poisoning

1. Dermal Contact and Ingestion 

  • Corrosive action: Less than that of sulphuric Acid. 
  • Skin is not usually corroded or damaged. 
  • Mucous membranes are readily corroded and destroyed. They are first grey or grey-white, then later it becomes brown and then black due to the production of acid hematin. 

2. Inhalation 

  • It affects the respiratory system and causes coughing and dyspnea, sneezing, and intense irritation of the throat and lungs.
  • It causes suffocation, a feeling of asphyxiation, and cyanosis (bluish skin color due to insufficient oxygen in the blood).

3. Contact with eyes 

  • It affects the eyes and results in Lacrimation (flow of tears) and photophobia. 

Diagnosis of Hydrochloric Acid Poisoning

  • Saliva: pH tested by litmus paper. 
  • Add a few drops of NaHCO3 on the stains present on the scene, clothes, etc., and produce bubbles indicating Acid. 
  • Arterial pH greater than 7.22 indicates acid ingestion. 
  • Chest and abdominal radiographs may show signs of gastric perforation. 
  • Endoscopy should be performed within 12 hours, which helps determine the treatment plan and prevent injuries. 

Fatal dose of Hydrochloric Acid Poisoning

It is mostly dependent on concentration. About 15 to 20 mL of concentrated acid is sufficient. 

Fatal period of Hydrochloric Acid Poisoning

The average fatal period of Hydrochloric acid poisoning is 12 to 24 hours. 

Post-Mortem Appearances of Hydrochloric Acid Poisoning

External Appearences  

  • Clothing – acid burns and stains. 
  • Linear burns- coursing down the angles of the mouth. 
  • Burns on the lip, chin, front of chest, hands 
  • Swelling of lips and mouth due to inflammation. 
  • Color of burnt areas- firstly grayish-white, then it becomes brown or black and leathery. 
  • It stimulates abrasion. 

Internal Appearences

  • Esophagus– Perforation is rare. 
  • Stomach- Mucosal folds are discolored brownish. It contains brownish fluid. 
  • Perforation is rare. 
  • Respiratory passages and lungs: acute inflammation and edema. 

Chemical Tests for Hydrochloric Acid Poisoning

  • Ammonia Test: Place an open bottle of ammonia near stomach contents. Vomitus or suspected poison produces thick white fumes of ammonium chloride. Standard Hydrochloride of the stomach is too dilute (0.2-0.5%) to produce similar fumes. 
  • Litmus Test: Suspected solution would turn blue litmus red. 
  • Silver Nitrate Test: Add silver nitrate into the suspected solution. If Acid is present, then it forms a white ppt of silver chloride. 

Medico Legal Importance 

  • Suicide- It is used in detergent suicides by producing hydrogen sulfide gas. 
  • Accidental- Latrogenic may be confused with antiseptics by negligent medical staff. 
  • Accidental exposures in the chemistry lab include dropping a bottle of HCl, constant inhalation of HCl fumes by chemistry staff, etc. 
  • Homicidal- Very rare due to its corrosive nature. 
  • Abortifacient- Rarely introduced in the vagina to produce abortion. 


Hydrochloric Acid is a corrosive poison and hazardous to the human body. Acute (short-term) inhalation exposure may cause eye, nose, respiratory tract irritation and inflammation, and pulmonary edema in humans, and sometimes in extreme cases, it can also cause death. 

Hydrochloric Acid is a natural component of the stomach that helps to digest food. It is used to process steel in the steel industry, used as the material of choice for suspension bridges, cars, and trucks, and is also used to produce batteries, fireworks, and photoflash bulbs. 

Categories: Toxicology


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