According to the Environmental Protection Agency, HCl stands for hydrochloric acid, or hydrogen chloride. It has a large number of uses, both in nature and manufacturing.
Thorne Research indicates that HCl is found in the human stomach. It is the gastric acid that works to help digest food. Specifically, HCl instigates the release of enzymes that digest proteins. The EPA states that HCl is used in many commercial fields, such as the photographic, textile, ore refining and rubber industries. This chemical is included in the production of dyes, fertilizers and electroplating. If a strong concentration is used, HCl is caustic and potentially dangerous to eyes, bare skin and exposed mucous membranes. Inhalation sometimes leads to irritation or inflammation of the respiratory tract.