Ammonium Chloride (NH₄Cl) is a chemical compound composed of one ammonium ion (NH⁴⁺) and one chloride ion (Cl^-). It is a white, crystalline powder that is highly water-soluble and forms a weakly acidic solution when mixed with water.

In the chemical industry, ammonium chloride is used as a starting material for the production of other chemicals such as ammonium nitrate (fertilizer), ammonium sulfate, and urea.

In the metallurgical industry, ammonium chloride is used as a flux in the purification of metals such as zinc and copper.

In the food industry, ammonium chloride is used as a flavoring agent and a source of ammonia in some types of baking powder. E-number is E510.

In the medical industry, ammonium chloride is used as an expectorant to help loosen and clear mucus from the respiratory tract and to help reduce the symptoms of certain respiratory conditions such as bronchitis and asthma.

In the agriculture industry, ammonium chloride is used as a fertilizer to provide plants with ammonium, which is an essential nutrient for plant growth and development.

In drilling industry, Ammonium Chloride is used as a thinning agent and clay stabilizer for drilling muds. It helps to control the viscosity of muds and also to prevent clay swelling and sloughing. It is also used to adjust the pH of the muds and to act as a source of ions for clay stabilization.

Ammonium chloride is generally considered safe for human consumption and for use in products. However, excessive consumption can cause respiratory problems and is toxic in high concentrations.