What Hazards Are Related to Hydrochloric Acid?

Hydrochloric acid (HCl), also known as muriatic acid, is a colorless solution with a pungent, irritating odor. The acid forms when hydrogen chloride dissolves in water. Its molecular weight is 36.47 g/mol. It is highly corrosive, and can release toxic gas when exposed to air. Common uses for hydrochloric acid include fertilizer production, steel pickling and food manufacturing.

Acute Effects

• The acute effects of hydrochloric acid usually occur during or soon after contact. Potential acute results of inhalation include burning and itching in the nose and throat, coughing, chest pain and pulmonary edema (edema may not become evident until several hours after exposure). Acid fumes may also cause burning eyes. Ingestion of hydrochloric acid can severely damage the mucous membranes of the mouth, esophagus and stomach; strong solutions may result in vomiting blood. Skin contact can cause severe burns and scarring, especially if the acid solution has a concentration of 10 percent or higher.

Chronic

• Chronic effects develop slowly, after repeated exposures to lower concentrations of hydrochloric acid. Symptoms may include dermatitis and gastritis, and erosion and discoloration of teeth. Chronic bronchitis with cough and shortness of breath is another common side effect of ongoing exposure to hydrochloric acid.

Treatment

• Any exposure to a strong hydrochloric acid solution requires medical attention. However, you can take steps to limit injury while waiting for treatment. Remove clothing soaked with hydrochloric acid as soon as possible. In the event of skin contact, flush the skin with water for at least 15 minutes without washing or scrubbing. If hydrochloric acid gets into the eyes, flush them with water for 15 minutes, lifting the upper and lower lids. In the event of ingestion, drink water or milk immediately to dilute the acid, unless symptoms make swallowing impossible. If hydrochloric acid fumes are present, move to fresh air immediately.

Safety Precautions

• Prevent hazardous exposure to hydrochloric acid in the workplace and laboratory by following all applicable safety recommendations. Handle the acid in a well-ventilated area, and store it in airtight containers. Wear safety glasses; rubber or Neoprene gloves; protective clothing; and safety shoes or boots to prevent exposure to the eyes and skin when mixing, pouring or transferring the acid. Note the location of the safety shower and eyewash station, in case you are exposed to the acid. Wear an 8-inch face shield when handling any acid with a pH of 3.0 or less. Use a respirator if the permissible exposure limit (PEL) exceeds the OSHA recommendation of 5 ppm per eight-hour shift.