THE FACTS ABOUT AMMONIA
Note to reader: This fact sheet is intended to provide general awareness and education on a specific chemical agent.
For information on preparedness and response (e.g., for first responders and emergency medical personnel), please
refer to the following Department resources:
Chemical Terrorism Preparednessand Response Card
Chemical Terrorism Wall Chart
What is ammonia?
Ammonia (NH3) is one of the most commonly produced industrial chemicals in the United
States. It is used in industry and commerce, and also exists naturally in humans and inthe
environment. Ammonia is essential for many biological processes and serves as a precursor for
amino acid and nucleotide synthesis. In the environment, ammonia is part of the nitrogen cycle
and is produced in soil from bacterial processes. Ammonia is also produced naturally from
decomposition of organic matter, including plants, animals and animal wastes.
Some chemical/physical propertiesof ammonia are:
• At room temperature, ammonia is a colorless, highly irritating gas with a pungent,
• In pure form, it is known as anhydrous ammonia and is hygroscopic (readily absorbs
• Ammonia has alkaline properties and is corrosive.
• Ammonia gas dissolves easily in water to form ammonium hydroxide, a caustic solution
and weak base.
• Ammonia gas is easilycompressed and forms a clear liquid under pressure.
• Ammonia is usually shipped as a compressed liquid in steel containers.
• Ammonia is not highly flammable, but containers of ammonia may explode when
exposed to high heat.
How is ammonia used?
About 80% of the ammonia produced by industry is used in agriculture as fertilizer. Ammonia is
also used as a refrigerant gas, for purificationof water supplies, and in the manufacture of
plastics, explosives, textiles, pesticides, dyes and other chemicals. It is found in many household
and industrial-strength cleaning solutions. Household ammonia cleaning solutions are
manufactured by adding ammonia gas to water and can be between 5 and 10% ammonia.
Ammonia solutions for industrial use may be concentrations of 25% or higher and arecorrosive.
How can people be exposed to ammonia?
Most people are exposed to ammonia from inhalation of the gas or vapors. Since ammonia exists
naturally and is also present in cleaning products, exposure may occur from these sources. The
widespread use of ammonia on farms and in industrial and commercial locations also means that
exposure can occur from an accidental release or from adeliberate terrorist attack.
Anhydrous ammonia gas is lighter than air and will rise, so that generally it dissipates and does
not settle in low-lying areas. However, in the presence of moisture (such as high relative
humidity), the liquefied anhydrous ammonia gas forms vapors that are heavier than air. These
vapors may spread along the ground or into low-lying areas with poor airflow wherepeople may
What is ammonia’s mechanism of action?
Ammonia interacts immediately upon contact with available moisture in the skin, eyes, oral
cavity, respiratory tract, and particularly mucous surfaces to form the very caustic ammonium
hydroxide. Ammonium hydroxide causes the necrosis of tissues through disruption of cell
membrane lipids (saponification) leading to cellulardestruction. As cell proteins break down,
water is extracted, resulting in an inflammatory response that causes further damage.
What are the immediate health effects of ammonia exposure?
Inhalation: Ammonia is irritating and corrosive. Exposure to high concentrations of ammonia
in air causes immediate burning of the nose, throat and respiratory tract. This can cause
bronchiolar and alveolar...