It causes burns on contact with eyes, skin, and mucous membranes.
Anhydrous ammonia is one of the oldest commercial refrigerants known.
Other uses include metal treating operations such as nitriding, sintering, and furnace brazing. Ammonia is also used the chemical industry to make a host of products. Gunpowder and sulfuric acid are a couple of well known products that use ammonia as an ingredient. Ammonia is produced primarily by the Haber process whereby nitrogen and hydrogen are combined directly. A less important method is the calcium cyanamide process which produces ammonia directly from limestone, carbon, nitrogen, and steam.