Ammonium nitrite

Ammonium Nitrite. , NH 4 NO 2 , is a salt containing ammonium and nitrite ions. It is used as a rodenticide, microbiocide, and agricultural pesticide, and is highly toxic to humans and aquatic organisms.


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  • 1 Nitrite
  • 2 Nitrates and nitrites
  • 3 Nitrification
    • 1 Ecotoxicology
  • 4 Health effects
  • 5 Health problems
  • 6 Removing nitrites from your water
  • 7 Sources
  • 8 External links


Ammonium or ammonium nitrite. Ammonia salt of nitrous acid, with the chemical formula NH 4 NO 2 . It is prepared by double decomposition between sodium nitrite and ammonium chloride:

NaNO 2 + ClNH 4 = NaCl + NH 4 NO 2

This compound is very unstable in the solid state , so it is only obtained in the dissolved state. Due to the effect of heat, the solution releases nitrogen , which is why it is usually used in the laboratory to obtain this gas .


Nitrates and nitrites

Nitrates and nitrites are naturally occurring ions that are part of the nitrogen cycle .

Natural nitrate levels in surface and groundwater are generally a few milligrams per liter. In many groundwater, an increase in nitrate levels has been observed due to the intensification of agricultural and livestock practices. Concentrations can reach several hundred milligrams per liter. In some countries, up to 10% of the population may be exposed to nitrate levels in drinking water above 50 mg / l.

In general, when nitrate levels in drinking water are below 10 mg / l, the main source of nitrate intake for humans is vegetables. When nitrate levels in drinking water exceed 50 mg / l, drinking water will be the main source of total nitrate consumption.

Extensive epidemiological data support the current guideline value of 10 mg / l for nitrate-nitrogen proposed by the World Health Organization (WHO). However, this value should not be expressed on the basis of nitrate nitrogen but on the basis of nitrate itself, since it is the chemical species that poses a health hazard , and the guideline value for nitrate is therefore 50 mg / l.


Nitrification is the oxidation of an ammonium compound to nitrite, especially by the action of nitrifying bacteria called Nitrosomes. The nitrites will then be oxidized to nitrates by the Nitrobacter bacteria.

Nitrate is less toxic than nitrite and is used as a food source by living plants.

The process of converting ammonium to nitrate is outlined in the nitrogen cycle.

Nitrification is faster at a pH of 7-8 and at temperatures of 25-30oC. Nitrification causes the pH of the water to drop.



Nitrite levels higher than 0.75 ppm in water can cause stress in fish and higher than 5 ppm can be toxic.

Nitrate levels between 0 and 40 ppm are generally safe for fish. Anything over 80 can be toxic.


Health effects

When nitrite enters the bloodstream, it reacts with hemoglobin to form a compound called methemoglobin. This compound reduces the ability of the blood to carry oxygen. The oxygen level drops, and babies show symptoms of a disease called methemoglobinemia, also known as “blue baby disease.”

The most obvious symptom of methemoglobinemia is the appearance of a bluish cast to the skin, particularly around the eyes and mouth. If discovered quickly, this disease can be successfully treated with an injection of methylene blue, which converts methemoglobin back to hemoglobin. The disease is extremely serious if left untreated: death occurs when 70 percent of the body’s hemoglobin has been converted to methemoglobin.

A relationship has been shown between infant deaths from methemoglobinemia and high levels of nitrate in water.

Health problems

The rumen is the first division of the stomach of a ruminant animal, in which most of the food is collected immediately after being swallowed and from which it is later returned to the mouth in the form of a food bolus to be better chewed. Bacteria present in the rumen of ruminant animals such as cattle and sheep convert nitrate to nitrite, causing nitrate poisoning.

Pigs and chickens do not have a rumen, because they are monogastric animals, so they eliminate nitrate quickly through urine. Young monogastric animals, however, are similar to human infants in that they are highly susceptible to nitrate poisoning until their digestive systems develop.

Horses are the monogastric animals most susceptible to nitrate poisoning because they have a large cecum that acts like the rumen, transforming nitrate to nitrite. High levels of nitrate can be found in plants due to overfertilization or stress. This can harm livestock much more than if the nitrate is ingested from drinking water with a high concentration of nitrates.

Some of the symptoms of methemoglobinemia in animals are coordination problems, difficulties in breathing, blue discoloration of the mucous membranes, vomiting and abortions. In dairy cows a reduction in production can be noticed without the cow showing any symptoms. If you suspect that your animals may be poisoned by nitrates, your vet can test them and, if necessary, inject methylene blue, the antidote.

Recently, several other health problems have been linked to high concentrations of nitrates. Some studies suggest that an increase in esophagus and stomach cancers may be related to N-nitrosamines, organic compounds formed in the mouth or in the digestive system by the interaction of nitrite (formed from nitrate) with compounds that contain organic nitrogen. (secondary amines). N-nitrosamines are potent animal carcinogens.

Removing nitrites from your water

An easy solution to removing nitrites from your water is by oxidizing them to nitrates (as we’ve said before, nitrates are much less toxic than nitrites). This can be achieved by injecting ozone into the water. Ozone is a highly oxidizing chemical that will oxidize all nitrites to nitrates, thus eliminating the toxicity caused by nitrites.


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