Safety First with Anhydrous Ammonia Applications

By Angie Rieck-Hinz and Joshua Michel 

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.
• SEEK IMMEDIATE MEDICAL ATTENTION, EVEN FOR BRIEF EXPOSURES!