NDSU Extension - Mercer County


| Share

Understanding Anhydrous Ammonia

anhydrous ammonia, fertilizer, nitrogen fertilizer

Submitted by Craig Askim, Extension Agent/Agriculture and Natural Resources

This time of year, farmers are busy planting their fields and many farmers use anhydrous ammonia. Many non-agricultural people fear this fertilizer. Anhydrous does have a potential risk, but the product is actually very safe if handled correctly. Education is the key. Below is an article that explains anhydrous ammonia in great detail and some basic information that all of us should know if an accident should occur.

More anhydrous ammonia is used as fertilizer in North Dakota than any other nitrogen fertilizer source. Anhydrous ammonia is classified as a hazardous substance. Most accidents with anhydrous ammonia are due to uncontrolled releases. Few problems occur when the ammonia is being handled and applied as intended. Most uncontrolled releases are due to improper procedures, careless or untrained workers, or faulty equipment.

Anhydrous ammonia (NH3) is a nitrogen crop fertilizer that can cause severe chemical burns; frostbite to the eyes, skin, and respiratory tract; and death. It is important for all individuals working with this type of fertilizer to understand the potential risks, necessary safety precautions, and proper response in the event of accidental contact.

Anhydrous ammonia is a hygroscopic compound, meaning that it takes up water from the nearest source, which can include the human body—especially the eyes, lungs, and skin because of their high moisture content. Anhydrous ammonia is caustic, corrosive, and damaging to tissue high in moisture content when it contacts the human body. Anhydrous ammonia inhalation incidents are typically severe because the victim’s throat can swell shut, causing suffocation. When vapors or liquid come in contact with a person’s eyes, blindness may occur.

Typically, anhydrous ammonia is stored under pressure, but it vaporizes to a colorless gas. It has a unique odor that can be detected at a low concentration of 5 ppm. The concentration in fertilizer is approximately 1,000,000 ppm, but even brief exposure to a concentration of 2,500 to 6,500 ppm can result in death.

Anhydrous ammonia is transported under pressure as a liquid, so all equipment used for transport must be designed for use under high pressure to avoid ruptures or breaks. Incidents can occur when anhydrous ammonia escapes from transfer hoses or valves, equipment malfunctions and sprays anhydrous ammonia in multiple directions, hoses pull apart during transportation or application, and so on.

Basic First Aid for Anhydrous Ammonia Exposure

The first-response treatment for anhydrous ammonia exposure is to flush the exposed area (skin, nose, throat, eyes, and so on) with clean water for a minimum of 15 minutes.

  • Flush the exposed area immediately to decrease injury caused by the anhydrous ammonia coming in contact with skin or clothes. Although clean water is the ideal resource for flushing exposed areas of the body, if you do not have water available, other nontoxic liquids, such as cold coffee or orange juice, can be used.
  • Remove contaminated clothing unless the clothing is frozen to the victim’s skin.
  • Seek medical attention immediately and inform medical staff of the exposure to anhydrous ammonia so that they will not treat the wounds with oils or ointments that can intensify the damage.

If you find a person who is in a continuous stream of anhydrous ammonia, contact your local emergency service responders or 911. Inform the emergency medical responders about the type of incident so they can bring the proper equipment to the scene. A self-contained breathing apparatus (SCBA) and protective clothing are necessary to remove a person from a continuous stream. Rescue workers will contact a hazardous materials (HAZMAT) disposal team if HAZMAT services are needed at the scene.

Note that these guidelines are not comprehensive, and all individuals working with anhydrous ammonia should receive training in the proper response to exposure emergencies.

Source: Anhydrous ammonia safety. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from  http://www.extension.org/pages/63196/anhydrous-ammonia-safety.

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.