Farming safety: Anhydrous ammonia fertilizer

Although anhydrous ammonia is readily available, fairly easy to apply, and one of the most efficient agricultural fertilizers available, it also is one of the most potentially dangerous chemicals for farm workers. Because of this, it is illegal to hire someone under age 16 to work with anhydrous ammonia, and workers need training in the safe use of this chemical.

“Anhydrous” means “without water,” so this fertilizer is always “thirsty.” Given the chance, it will rapidly mix with any moisture — in the air, soil, or in people. Contact with skin can cause severe chemical burns, cellular destruction, frostbite, and dehydration. Contact with mucus membranes is especially dangerous and could quickly result in blindness, respiratory damage, or death.

Anhydrous ammonia must be stored and used under high pressure in well-maintained specially made equipment that resists corrosion, chemical reactions, and pressures up to 250 psi. Most accidents happen when transferring ammonia from a storage tank to the applicator tank, so special care must be taken during this process.

Accidents also occur because of overfilling tanks, inadvertently knocking open hose valves, venting pressure release valves too closely to a person, using old or damaged equipment, and overturning tanks while driving.

To help reduce the severity of injuries if an accident does happen, workers should wear proper personal protective equipment:
  • Non-vented goggles at a minimum, but preferably a full-face shield
  • Long, heavy rubber gloves
  • Heavy long-sleeved shirt and pants
  • Chemical-resistant boots
  • Respirator with ammonia cartridges

First aid for exposure to anhydrous ammonia is water — and lots of it. Get away from the source of the ammonia, remove contaminated clothing, and flush skin or eyes for at least 20 minutes. Do not cover injuries with ointments because these will seal in the caustic chemical. Seek medical attention and call 911 for emergencies.