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Nitric Acid


CAS No. 7697-37-2

Nitric acid (HNO₃) is a colorless liquid with yellow or red fumes with an acrid odor. Exposure to nitric acid can cause irritation to the eyes, skin, and mucous membrane; it can also cause delayed pulmonary edema, pneumonitis, bronchitis, and dental erosion. Nitric acid is highly corrosive. Workers may be harmed from exposure to nitric acid. The level of exposure depends upon the dose, duration, and work being done.

Nitric acid is used in many industries. It’s used in the manufacture of fertilizers, dyes, and explosives. Nitric acid is also used in the polymer industry. Some examples of workers at risk of being exposed to nitric acid include the following:

  • Factory workers in plants that produce nitric acid
  • Factory workers in plants that manufacture explosives
  • Workers in facilities that use nitric acid

NIOSH recommends that employers use Hierarchy of Controls to prevent injuries.  If you work in an industry that uses nitric acid, 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 nitric acid. Useful search terms for nitric acid include “aqua fortis,”  “engravers acid,” “hydrogen nitrate,” “red fuming nitric acid,” “white fuming nitric acid.”

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