Ammonia is one of the most widely used compounds in the United States, serving as a raw material for the production of many important compounds and as a nutrient for the growth of crops.

About 90 percent of all the ammonia used in the United States goes to the production of fertilizers.

The Haber-Bosch process remains the most common form of ammonia production in many countries, including the United States.

Ammonia is used in a variety of forms as a fertilizer.

In addition to its use in the manufacture of fertilizers and explosives, smaller amounts of ammonia are used: As a refrigerant; In the manufacture of plastics; As a raw material in the manufacture of other nitrogen-containing chemicals; In the production of dyes; As a rocket fuel; For the neutralization of acids during the refining of petroleum; In order to produce specialized types of steel; and As a nutrient in yeast cultures in food processing operations.

The next largest use of ammonia is in the synthesis of nitric acid (HNO3). In a process developed by the German chemist Wilhelm Ostwald (1853–1932), ammonia, oxygen, and water are reacted together in a series of steps that results in the formation of nitric acid. Nitric acid, the thirteenth most important chemical in the United States in terms of productions, has a number of important uses, including the manufacture of explosives. Like the Haber-Bosch process, the Ostwald process contributed to the success experienced by Germany during World War I.

Both gaseous and liquid ammonia pose moderate health hazards to those who come into contact with them. For example, farmers who handle liquid ammonia risk the possibility of painful blistering of the skin or damage to the mucous membranes if they come into contact with the ferilizer. Ammonia fumes can irritate the mouth, nose, and throat, causing coughing and gagging responses. Higher levels of exposure may irritate the lungs, resulting in shortness of breath and producing headaches, nausea, and vomiting. Very high exposures can cause a buildup of fluid in the lungs that can result in death. Since ammonia is a common ingredient of many household products, everyone should be aware of its health risks, although the threat posed by such products is, in fact, very small.

The largest use of ammonia is in fertilizers,

Ammonia, composed of three parts hydrogen and one part nitrogen, is a sharp-smelling, flammable, and toxic gas that is very soluble in water, where it acts as a base in its chemical reactions.

The synthesis reaction itself produces some heat, and great attention is given to heat efficiency and use of waste heat.

These bacteria and algae possess an enzyme called nitrogenase that permits them to convert nitrogen to ammonia at 77°F (25°C) and 1 bar of pressure, much milder conditions than those of the Haber-Bosch process.