Hydrogen Chloride


CAS No. 7647-01-0

Hydrogen chloride (HCl) is a colorless to slightly yellow gas with a pungent odor. Hydrogen chloride can irritate the skin, nose, eyes, throat, and larynx. Exposure to liquid hydrogen chloride may cause frostbite. Workers may be harmed from exposure to hydrogen chloride. The level of harm depends upon the dose, duration, and work being done.

Hydrogen chloride is used in many industries. It’s used to clean, pickle, and electroplate metals, tan leather, and refine and produce a wide variety of products.  Some examples of workers at risk of being exposed to hydrogen chloride include the following:

  • Chemical workers in plants that use it to produce other chemicals
  • Factory workers in plants where metals are pickled
  • Workers in food processing plants
  • Factory workers who manufacture dyes and fertilizers
  • Factory workers in the rubber and textile industries

NIOSH recommends that employers use Hierarchy of Controls to prevent injuries.  If you work in an industry that uses hydrogen chloride, please read chemical labels and the accompanying Safety Data Sheets for hazard information. Visit NIOSH’s page on Managing Chemical Safety in the Workplace to learn more about controlling chemical workplace exposures.

The following resources provide information about occupational exposure to hydrogen chloride. Useful search terms for hydrogen chloride include “anhydrous hydrogen chloride” “aqueous hydrogen chloride,” and “hydrochloric acid.”

NIOSH Chemical Resources

Related NIOSH Resources

Selected Publications

Related Resources

International Resources

Page last reviewed: June 21, 2019