Hydrochloric Acid

Hydrochloric acid is the solution of hydrogen chloride (HCl) in water. It is a highly corrosive, strong mineral acid and  is found naturally in gastric acid.

Gastric acid is one of the main secretions of the stomach. It consists mainly of hydrochloric acid and acidifies the stomach content to a pH of 1 to 2. Gastric acid acts as a barrier against microorganisms to prevent infections and is important for the digestion of food. Its low pH denatures protein and thereby makes them susceptible to degradation by digestive enzymes.

The stomach itself is protected from the strong acid by the secretion of a thick mucus layer and of neutralizing sodium bicarbonate. Heartburn or peptic ulcers can develop when these mechanisms fail.