The facts about ammonia

Following the ammonia accident in Emek Hefer (6.11.14), an explanation of ammonia gas and the ways to treat victims

Tonight, an ammonia leak occurred at the Hod-Hafer plant as a result of a work accident - workers wanted to saw one pipe but closed the ammonia taps of another pipe. One firefighter was killed and ten firefighters were injured in the incident. Before us are the scientific aspects related to exposure to ammonia.

What is ammonia?
Ammonia (NH3) is one of the most common industrial chemicals in the US. It is used in industry and commerce and also exists naturally in the human body and in the environment.
Ammonia is an essential substance for many chemical processes and is used as a component in the synthesis of amino acids and nucleotides. In the environment, ammonia is part of the nitrogen cycle and is produced in the soil by bacterial processes. Ammonia is also produced naturally in the processes of breaking down organic matter including plants, animals and animal waste.
The main chemical and physical characteristics of ammonia are:

• At room temperature, ammonia is a colorless gas, but has a pungent odor and causes suffocation.
• In its pure form, ammonia gas is dry (without water) and therefore absorbs moisture.
• Ammonia has basic properties (alkaline) and is corrosive.
• Ammonia gas dissolves easily in water and forms a base (ammonium hydroxide) - a caustic solution.
• Ammonia gas is transported in compressed liquid form in steel tanks.
• Ammonia gas is not a particularly flammable gas, but ammonia containers can explode when exposed to heat.

How is ammonia used?
About 80% of the ammonia gas produced in industry is used in agriculture as fertilizer. Ammonia is also used as a cooling gas in refrigerators, for water purification and for the production of plastics, explosives, textiles, pesticides, dyes and other chemicals.
It is found in household and industrial cleaning solutions. Household cleaning solutions are produced by adding ammonia gas to water and can contain between five and ten percent ammonia. Ammonia solutions for industrial use may contain 25% or more ammonia and are corrosive.
How can humans be exposed to ammonia?
Most people are exposed to ammonia by breathing gas or vapor. Because the gas exists naturally and is found in cleaning products, exposure may occur from these sources. The common use of ammonia on farms, in industry and commercial sites means that the exposure may be caused by an accidental release or as a result of a deliberate terrorist attack.
Ammonia gas without water is lighter than air and will rise to the top, so it disperses quickly and does not settle in low areas, however in the presence of moisture (such as a relatively high relative humidity), the gas turns into a liquid and creates vapor heavier than the air. These vapors may spread along the ground or to low areas with thin air flow and the people living there may be exposed.

What is the mechanism of action of ammonia?
Ammonia reacts immediately in contact with the moisture on the skin, eyes, lips, respiratory tract, in particular their mucous surface, and forms a caustic ammonia base (ammonium hydroxide causes). Caustic ammonia base causes cell death through the destruction of lipids in the cell membrane (saponification). When the proteins in the cell break down, the water is squeezed out and the result is an inflammatory reaction that causes additional damage.

What are the immediate health effects of ammonia exposure?
Ammonia is a corrosive gas with a pungent smell. Exposure to a high concentration of ammonia causes immediate burning in the nose, throat and respiratory tract. This can cause bronchitis, edema and destruction of the airways, resulting in difficulty breathing or even respiratory failure.

Inhalation of lower concentrations can cause coughing and burning in the nose and throat. The smell of ammonia provides an early warning of the presence of the gas, but ammonia also causes adaptation to the sense of smell and reduces awareness during prolonged exposure to the gas at low concentrations.

Children exposed to the same concentrations of ammonia vapor as adults may receive larger doses because their lungs have a larger surface area relative to their body weight and are therefore exposed to relatively more ammonia. In addition, they may be exposed to higher concentrations than the adults in the same place due to their lower altitude and the greater concentration of ammonia vapors that are primarily near the ground.

Contact with the skin or eyes: exposure to low concentrations of ammonia in the air or in the solution may cause irritation to the skin and tissues. Higher concentrations of ammonia can cause injury and severe burns. Contact with concentrated ammonia solutions such as in industrial cleaning agents may cause corrosive damage including skin burns, irreversible eye damage or blindness. The full extent of the damage to the eye may not become clear until a week after exposure. Contact with liquid ammonia can also cause frostbite injury.

Ingestion: Exposure to high concentrations of ammonia as a result of swallowing ammonia solution causes corrosive damage to the mouth, throat and stomach. Ingesting ammonia as a rule does not cause general poisoning.

How should ammonia victims be treated?
There is no antidote to ammonia poisoning, but the effects of ammonia can be treated, and most victims recover. Immediate purification of the ammonia from the skin and eyes using a large amount of water. The treatment includes supportive measures, including oxygen administration, treatment with bronchodilators and airways. Treatment of ammonia ingestion should be treated by diluting the substance by drinking milk or water.
The facts about ammonia, from the New York State Department of Health website