What is Ammonium Bicarbonate

Ammonium bicarbonate (also known as ammonium hydrogen carbonate) is a mildly basic inorganic compound with the formula (NH4)HCO3. It is a colourless, crystalline solid with the odour of ammonia. It is soluble in water, but insoluble in most organic solvents including ethanol, carbon disulphide and concentrated ammonia. It is volatile in solution and degrades readily into ammonia and carbon dioxide in an endothermic reaction. This property makes it useful as a leavening agent in baked products such as cakes and biscuits, and as a buffer in applications such as lyophilization and matrix assisted laser desorption. It is also a commonly used reagent in many industrial and research procedures. Ammonium bicarbonate is produced by passing carbon dioxide gas countercurrently through a descending stream of aqueous ammonia (ammonium hydroxide), usually in either a packed tower or an absorption column. Carbon dioxide gets absorbed into the liquid stream of ammonia and water, and reacts to form ammonium bicarbonate as below:CO2 + NH3 + H2O → (NH4)HCO3 . Since the reaction is exothermic and ammonium bicarbonate is unstable, the system, especially the lower portion of the tower, is generally maintained at a lower temperature.Once the solution is sufficiently saturated, the ammonium bicarbonate crystallizes as a white solid. These crystals are separated from the solution by precipitation, followed by centrifugal separation and washing. The crystals are then dried using air at 50°C.Upon refining, the crystals are dissolved in water then recrystallized by adding ethanol.

Measures in Case of Accidents

Remove to fresh air. If not breathing, give artificial respiration. If breath areaing is difficult, give oxygen. Call a physician.

DO NOT INDUCE VOMITING. Give large quantities of water. Never give anything by mouth to an unconscious person. Call a physician immediately.

Skin Contact:
Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Get medical attention. Wash clothing before reuse. Thoroughly clean shoes before reuse.

Eye Contact:
Immediately flush eyes with plenty of water for at least 15 minutes, lifting lower and upper eyelids occasionally. Get medical attention immediately.

The Uses of Ammonium Bicarbonate

Ammonium bicarbonate (also known as ammonium hydrogen carbonate) is produced by passing carbon dioxide gas counter currently through a descending stream of aqueous ammonia (ammonium hydroxide), usually in either a packed tower or an absorption column.

Food Industry

In the food industry, ammonium bicarbonate is used as a raising agent or leavening agent, as it releases gas in the baked good, creating a light texture. Examples include cookies and crackers, and steamed buns and Chinese almond cookies in China. Before modern day baking powder, it was also a staple good in households, for example in the form of hartshorn/hornsalt in Scandinavian countries. Although using ammonium bicarbonate does result in a slight ammonia smell during baking, it dissipates quickly and has no effect on the taste. However, ammonium bicarbonate cannot be used for moist, bulky baked goods, such as normal break or cakes, as some ammonia may remain trapped inside and result in an unpleasant taste.


Ammonium bicarbonate is also widely used as a nitrogen fertilizer, especially in China, as the ammonium ions can be released into the soil and either absorbed by the soil colloid, lattice-fixed or converted into nitrate nitrogen. Its benefits are that it leaves little to no residue in the soil after the ammonium ion is absorbed by the plants, has minimum impact on the pH of the soil, and is quick-acting and useful in the long run. It is limited however due to its instability and tendency to decompose. This can however be remedied by the addition of a crystalline modifier.

Product Specification

  • CAS NO.
  • 1066-33-7
  • NH4HCO3
  • 79.056 g/mol
  • Ammonium hydrogen carbonate, Carbonic acid, Monoammonium salt, Monoammonium carbonate, Acid ammonium carbonate

Physical and chemical properties


  • PH
  • Colorless crystal or white powder.
  • 105°C
  • 143.04°C (rough estimate as it decomposes)
  • 11.9 g/100 mL (0°C)
    21.6 g/100 mL (20°C)
    36.6 g/100 mL (40 °C)
  • 1.586 g/cm3
  • 7.0-8.5 (25℃, 1M in H2O)
  • Stable. Incompatible with strong acids, alkali metals