Hydrochloric acid is rated and regulated as a toxic substance.
Concentrated hydrochloric acid, known as fuming hydrochloric acid, will form acidic mist. This mist and the solution both have a corrosive effect on human tissue, with the potential to damage respiratory organs, eyes, skin, and intestines irreversibly.
Dangers of hydrochloric acid through exposure
Exposure via oral consumption can cause corrosion of the mucous membranes, esophagus, and stomach, with nausea, vomiting, and diarrhoea. Contact to skin produces severe burns, ulceration, and scarring.
Exposure through inhalation can cause coughing, hoarseness, inflammation and ulceration of the respiratory tract, chest pain, and pulmonary edema (fluid accumulation in the lungs).
A toxic chlorine gas can also be produced when mixing hydrochloric acid with common oxidising chemicals, such as bleach (sodium hypochlorite).
Be aware of the dangers of hydrochloric acid when handling. It is important to wear personal protective equipment such as acid-proof gloves, protective eye goggles, chemical-resistant clothing and shoes so as to minimise risk of harm.
One of the most difficult parts of the process when acid etching metal surfaces is safety. When working with acid in any form, always add the acid to water and NOT water to acid. Adding water to acid can cause a chemical reaction, which may produce a very rapid heat. This can, on occasion, cause an explosion of the solution.
