It’s easy to get complacent when working with anhydrous ammonia, said Kent McGuire, safety and health coordinator with The Ohio State University’s College of Food, Agricultural, and Environmental Sciences. 

But injuries from accidental exposure “could get very serious, very quickly,” McGuire said.

Anhydrous ammonia is one of the most widely used sources of nitrogen fertilizer among corn growers. The product is stored in tanks, called nurse tanks, as a liquid under pressure. Once it is released into the soil or the air it turns to vapor.

Anyone who handles anhydrous ammonia needs to understand the potential for injury and know how to respond in an emergency, McGuire said.

“Once anhydrous ammonia makes contact with the skin, it can freeze tissue and cause a skin burn,” McGuire said. “As far as inhalation goes, it takes a very low dose of anhydrous ammonia to affect the lungs and breathing. In some cases, an unintended exposure can give you the sensation that the wind has been knocked out of you.”

Caustic burns to the skin and severe irritation to the eyes, lungs and respiratory system are all possible, and exposure to high concentrations can cause permanent injury, he said.

“Any time you’re working with the nurse tanks or the applicator and there is the potential for an unintentional release, you need to have on your personal protective equipment,” McGuire said. “Most people increase the risk of injury simply because they forgot or didn’t take the time to put on their personal protective equipment first.”

McGuire advises farmers to always be aware of their surroundings when working with anhydrous ammonia.

“Leave yourself an escape route in case there’s a release,” he said. “You want to avoid being downwind of it. The quicker you can get away from it and get to fresh air, the better.”

McGuire suggests reviewing the product safety data sheet themselves with any employees who will be working with anhydrous ammonia.

“It explains exposure controls, first aid measures, emergency procedures and specific handling practices you should be following,” he said.

In addition, he suggests checking with local anhydrous ammonia suppliers for training opportunities.

“Many will have customer in-services where they discuss proper handling and safety procedures,” McGuire said. “Take full advantage of that. They are well-versed in safety precautions, and you can learn a lot from your local supplier.”

McGuire recently wrote about working safely with anhydrous ammonia for Ag Safety S.T.A.T. – Safe Tactics for Ag Today, a newsletter by Ohio State University Extension’s Agricultural Safety and Health Program. OSU Extension is the outreach arm of the college.

Among McGuire’s recommendations:

  • Always have water readily available, including a squirt bottle of water to douse the eyes with, and 5 gallons of emergency water mounted on the nurse tank.
  • Follow recommended procedures for connecting and disconnecting nurse tanks and applicators. Shortcuts can lead to unintended release or unexpected exposure.
  • When changing nurse tanks or making field repairs, always work upwind of the applicator and the nurse tank. Applicator knives, flow meters, hose connections, bleeder valves and nurse tank valves can be exposure openings for an unintended release.
  • When changing nurse tanks, park the tractor upwind before opening bleeder valves or disconnecting hoses. This can minimize the chance of anhydrous ammonia entering the cab.
  • Hand-tighten valve handles. Over-tightening with a wrench can cause damage to the valve or seals.
  • Park nurse tanks, whether full or empty, downwind and away from neighboring houses, public areas and businesses.

For more of McGuire’s tips and other agricultural safety information from OSU Extension, see agsafety.osu.edu.

For additional information on anhydrous ammonia safety, see the National Ag Safety Database at nasdonline.org and search for “anhydrous ammonia.”