Effects of Inhaling Muriatic Acid Fumes

Hydrochloric acid was discovered in the first century by mixing vitriol with salt. It was used by medieval alchemists in their search for the “philosopher's stone,” that is, a chemical that converts base metals into gold. Muriatic acid is a diluted form of hydrochloric acid. It is a readily available chemical with many occupational uses: as a concrete etcher; as an industrial cleaner; in battery production, and more.

Muriatic acid vapors are extremely hazardous. The Environmental Protection Agency has not established a Reference Dose for the acid (Ref 4); therefore, consider the liquid or gaseous form to be highly toxic in all quantities.

Acute Effects on Health

Inhalation of muriatic acid vapors can cause immediate coughing, choking, chest pain and tightness, hoarseness and sore throat, rapid pulse, and bluish tint to lips and fingers. More severe effects include inflammation or burning of the windpipe and respiratory tract, coughing up of blood and pulmonary edema. According to the Environmental Protection Agency (Ref 4), laboratory rodents suffered lesions of the larynx and upper respiratory tract when exposed to vapors.

Chronic Exposure Effects on Health

Effects of Hydrochloric Acid Fumes

Learn More

Long-term exposure to muriatic acid vapors has been known to cause corrosion of teeth and severe lung damage leading to chronic bronchitis. Additional symptoms include gastritis; lesions in the trachea, nasal cavity, and larynx; photosensitization; circulatory failure, and death.

Cancer Risks

The EPA states that “no information is available on the carcinogenic effects of hydrochloric acid in humans.” (Ref 4) A study with laboratory rodents showed no carcinogen results with muriatic acid vapors. Because of the lack of study and data, the EPA has no classification for cancer risks from exposure to muriatic acid.