Ammonium chloride (\(\text{NH}_4\text{Cl}\)) is a white, crystalline salt composed of ammonium cations (\(\text{NH}_4^+\)) and chloride anions (\(\text{Cl}^-\)) that is highly soluble in water. While widely used across various industries and consumer products, it is classified as harmful if swallowed and an irritant to the eyes, skin, and respiratory system. The potential for toxicity is highly dependent on the concentration, the route of exposure, and the amount absorbed into the body.
Everyday Presence of Ammonium Chloride
Consumers encounter ammonium chloride in a diverse range of products. In agriculture, it serves as an important source of nitrogen in fertilizers. The compound is approved for use in the food industry under the designation E510, functioning as a yeast nutrient in bread making and providing a sharp flavor to certain foods, notably salty licorice.
In the pharmaceutical sector, ammonium chloride is included in cough and cold remedies, acting as an expectorant to thin and loosen mucus. It is utilized in industrial processes as a flux for soldering and galvanizing, cleaning metal surfaces by reacting with oxides. It can also be found in some household goods, including certain shampoos, body washes, and cleaning products.
How Ammonium Chloride Affects the Body
When a person ingests a large amount of ammonium chloride, the compound dissociates and is metabolized. The liver converts the ammonium ion (\(\text{NH}_4^+\)) into urea, liberating a hydrogen ion (\(\text{H}^+\)) into the bloodstream. The remaining chloride ion (\(\text{Cl}^-\)) combines with the free hydrogen ion to produce hydrochloric acid. This excess production of hydrogen ions overwhelms the body’s natural buffering capacity.
The subsequent buildup of acid leads to metabolic acidosis, characterized by a decrease in blood \(\text{pH}\) and a depletion of bicarbonate (\(\text{HCO}_3^-\)) reserves. The body attempts to compensate by increasing respiration to expel carbon dioxide. In severe cases, this chemical imbalance strains the kidneys, which work to excrete the excess acid. Uncontrolled metabolic acidosis can impair central nervous system function, manifesting as confusion or drowsiness.
Recognizing Exposure and Emergency Response
Exposure can occur through contact with the skin, eyes, inhalation of dust or fumes, or accidental ingestion. Inhaling dust or fumes causes immediate irritation to the respiratory tract. Symptoms of inhalation include a cough, sore throat, and, in severe cases, difficulty breathing. If inhalation occurs, the affected person should be immediately moved to fresh air, and medical attention should be sought if the breathing difficulties persist.
Direct contact with the skin or eyes causes localized irritation. Eye contact is particularly concerning and can lead to redness, pain, and serious eye damage. If the substance contacts the eyes, they must be flushed immediately with copious amounts of water for at least fifteen minutes, and any contact lenses should be removed if easily done. For skin contact, remove contaminated clothing, and thoroughly wash the affected area with soap and water.
Ingestion of a harmful quantity is characterized by symptoms such as nausea, vomiting, abdominal pain, and a sore throat. In cases of ingestion, the mouth should be rinsed, and the person should be given one or two glasses of water to drink. It is important to avoid inducing vomiting unless specifically instructed to do so by a medical professional or poison control center. Regardless of the route of exposure, if symptoms are severe or if a large amount of the substance was ingested, immediate medical advice or emergency services should be contacted. Medical monitoring is necessary for significant ingestions to assess for metabolic acidosis.