Facts about Ammonium bicarbonate

Ammonium bicarbonate, also called bicarbonate of ammonia, ammonium hydrogen carbonate, hartshorn, or powdered baking ammonia, is the bicarbonate salt of ammonia.

Ammonium bicarbonate is formed as shown below, or by passing carbon dioxide through a solution of the normal compound, when it is deposited as a white powder, which has no smell and is only slightly soluble in water.

Uses of Ammonium bicarbonate

This leavener is the precursor of today's baking powder and baking soda. Ammonium bicarbonate is used in the food industry as a raising agent (e.g., for gingerbread, digestive biscuit or Chinese youtiao) before the introduction of baking soda. Ammonium bicarbonate is still used in many food products, in addition to baking soda.

It is commonly used as an inexpensive nitrogen fertilizer in China, but is now being phased out in favor of urea because of its relatively low quality and instability. This compound is used as a component in the production of fire-extinguishing compounds, pharmaceuticals, dyes, pigments and it is also a basic fertilizer being a source of ammonia. Ammonium bicarbonate is still widely used in the plastic and rubber industry, in the manufacture of ceramics, in chrome leather tanning and for the synthesis of catalysts.
Cooking facts about Ammonium bicarbonate

Your kitchen would stink of ammonia while the cookies baked, but the cookies would not taste or smell of ammonia.

Side effects of Ammonium bicarbonate

Ammonium bicarbonate is an irritant to the skin, eyes and respiratory system. Ammonium bicarbonate from China used to make cookies was found to be contaminated with melamine, and imports banned in Malaysia in the 2008 Chinese milk scandal.

Effects of Ammonium bicarbonate in food

The levels of ammonium carbonate and bicarbonate in the diet from food additive use are extremely small compared to the levels required to cause physiological changes and pose no toxicological hazard. But I'm pretty sure it is harmful for health in the long run.

Toxicological studies (observation) of Ammonium bicarbonate on man

A number of clinical studies of duration less than 1 week have been carried out with ammonium chloride. In one report, a man was given 62 g of ammonium chloride in the diet over a 3-day period. No effects were reported except for increased red cell count, increased BUN and decreased plasma pH (Guest & Rapoport, 1940). In another study, 3 young men were given ammonium chloride in drinking-water at doses ranging from 52 to 105 g over 3-5 days. Headache, insomnia, nausea and diarrhoea occurred along with increased urinary acidity and ammonia. A reduction in glucose tolerance was also noted, consisting of hyperglycaemia and a slow return of blood sugar to fasting levels following glucose ingestion (Thompson et al., 1933).

Pregnant women (6 normal, 8 toxaemic, 3 hypertensive) were given 15 g/day of ammonium chloride in their beverage for a period of 3 days. Treated women experienced hyperventilation, anorexia, diminished thirst, nausea, and loss in weight. Urinary chloride, potassium, acidity and volume all increased, blood pH and CO2 decreased while haematocrit increased (Assali et al., 1955).

Dietary exposures of Ammonium bicarbonate

Ammonium bicarbonate at low levels is a preexisting component of the diet and is not known to be a toxic compound in the human diet. FDA has classified ammonium bicarbonate as Generally Regarded As Safe (GRAS) (21 CFR 582.1135), and allows its use as a direct food additive (21 CFR 184.1135). Because the product is contained within a polymeric substance, there will be minimal additional dietary exposure from this use (Ref. 1).

Read further on Ammonium bicarbonate by U.S Federal Environmental Protection Agency

---------------------------------
From Taiwan News: Taiwan government urged to locate melamine-tainted leavening agent

The Consumers' Foundation urged the government Monday to locate and make public the whereabouts of the full shipment of the melamine-tainted leavening agent ammonium bicarbonate imported from China.

After the discovery in Taiwan last month of melamine-contaminated milk powder and non-dairy creamer, it was also found that a total of 469 tons of ammonium bicarbonate imported by Taiwan's Sesoda Corp. from China was contaminated with the toxic chemical melamine.

The melamine content in a small portion of the imported ammonium bicarbonate was as high as 2,470 parts per million - more than 987 times the maximum permissible level, according to the foundation.

The foundation confirmed that some 384 tons of the melamine-tainted leavening agent had been distributed in domestic markets. It is believed to have been used in many baked products, such as deep-fried bread sticks, creamy custard buns, and as an additive to seaweed and squid. About 3,055 of the 3,479 bags of the melamine tainted ammonium bicarbonate distributed in Taichung City have been seized by the city's Health Bureau, and the other 424 bags were used in paper production, according to a report released by the city government Monday.