Safety First with Anhydrous Ammonia Applications

October 28, 2022 7:24 AM
Blog Post

It’s the time of year when farmers and retailers turn to thoughts about next year’s growing season, including fall anhydrous ammonia (NH3) applications for the next year’s corn crop.  See Is it time for fall nitrogen yet?!

The term “anhydrous” means without water. Because NH3 contains little to no water, it aggressively seeks out moisture, whether in soils or in your body.  As NH3 seeks out water, ammonia hydroxide is formed which is extremely caustic and can result in severe burns to your skin, eyes and respiratory tract. Low-dose exposure can cause irritation to eyes and skin that may result in burning or coughing; higher dose exposure and/or longer length of exposure can cause severe irritation, permanent damage to tissues including blindness, and even suffocation due to cell and membrane rupture in your respiratory tract. Another concern is the low boiling point of anhydrous ammonia. As liquid anhydrous ammonia vaporizes it has a temperature of -28°F, which can cause severe frostbite type burns.

Under normal temperature and pressure, NH3 is colorless gas that is lighter than air. NH3 is stored, transported and handled as a liquid via pressured tanks. Once the pressure is released, i.e., broken valve, broken hose or even application into soil, it returns to a gas and is capable of moving quickly into the atmosphere. Windy conditions may also move NH3 considerable distances.

Every precaution should be taken when filling tanks, coupling hoses, transporting tanks and applying NH3.

  • Always wear NH3 rated gloves and ventless goggles. Gloves should have long cuffs so the cuffs can be rolled to catch drips. Always be fully clothed in long pants, a long-sleeved shirt, and closed-toe shoes when working with NH3.
  • Never wear contact lenses when working with NH3 or maintaining equipment.
  • If an exposure to NH3 does occur, flush all exposed areas with water for at least 15 minutes. To facilitate this,
    • Always carry a personal eyewash bottle on you at all times when working with NH3 and application equipment.  This can help buy you time to get to your emergency water supply.
    • Do not apply lotions, oils or ointments to skin as this may intensify damage.
  • Each NH3 nurse tank must contain at least 5 gallons of emergency water supply.
  • During freezing weather keep an extra 5-gallon emergency water supply in the tractor/applicator cab to help reduce chances of the emergency supply being unavailable due to being frozen.
  • Always have an emergency water supply available when performing equipment maintenance.
  • Keep emergency water supplies clean, filled and accessible at all times.
  • Always use safety chains and a locking hitch pin when pulling nurse tanks.
  • Do not attempt to rescue a victim that is exposed to a continuous stream of anhydrous ammonia. Any attempt will likely result in additional victims. Rescuers must wear a self-contained breathing apparatus (SCBA) and protective clothing in order to stay safe.
  • In the event of an incident, IMMEDIATELY call 911 and make sure you are upwind.

Additional information on regulations and transport requirements can be found in Play it Safe with Anhydrous Ammonia.



Angie Rieck-Hinz Field Agronomist in NC Iowa

Angie Rieck-Hinz is a field agronomist in north central Iowa for Iowa State University Extension and Outreach. She has worked for ISU Extension and Outreach for over 30 years, serving in various roles on campus and now in the field.  She works closely with farmers on integrated pes...

Joshua Michel Field Agronomist in NE Iowa

Joshua Michel joins ISU Extension and Outreach as a field agronomist after working at the Muscatine Island Research and Demonstration Farm. While at the farm he was responsible for coordinating corn and soybean field studies that included planting, harvesting, tillage and pest management. Mi...