Image of a tractor spraying anhydrous ammonia (NH3) on to a field.

Safety Plans for Anhydrous Ammonia (NH3)

Updated January 1, 1 . AmFam Team

A powerful fertilizer delivering nitrogen to topsoil, anhydrous ammonia (NH3) is a popular-but-dangerous chemical applied onto farmlands across the US at the beginning of planting season. Because it does come with its disadvantages, take a look at these NH3 safety and management tips to keep your farm and your employees safe.

Anhydrous ammonia is widely utilized as an agricultural fertilizer because it is rich in nitrogen. However, it has the potential to be one of the most dangerous chemicals used in agriculture today and is classified as a hazardous substance. It is used and stored under high pressures and those who work with NH3 must be trained to follow safe handling procedures. Most accidents with anhydrous ammonia are due to uncontrolled releases. Here are some important facts about NH3:

Why Is Anhydrous Ammonia (NH3) Dangerous?

Because NH3 actively attracts water, animals and humans are at risk when exposed to this chemical. In addition to causing serious burns when you come into contact with NH3, it binds to the water in your skin and within your body. Here are a few important reasons why NH3 is so dangerous:

NH3 contains no water. Anhydrous is the Greek word for “without water.” As such, NH3 has a very strong attraction to water. The human body is 50 to 75 percent water including skin, eyes, nose, throat and lungs. When anhydrous ammonia comes in contact with human tissue it is extremely destructive and can cause severe chemical burns.

NH3 is a clear, colorless gas and has a very characteristic odor. The odor of NH3 is the strongest safety feature of the chemical. At a concentration of only 50 parts per million (ppm), one sniff tells what is in the air — and the odor alone will drive a person away from the area. At concentrations of more than 5,000 ppm, workers can be severely incapacitated or worse, so quick detection of leak is key to preventing injury.

NH3 is dangerous to humans. Handling and working with this chemical requires special precautions that need to be taken seriously to avoid injuring workers. When NH3 safety management plans are in place, the accidental release of a dangerous plume into the atmosphere can be minimized.

With the proper training, management and safety practices, NH3 can be used to produce healthy crops and can increase yield. Take a look at this safety information to understand how to protect yourself from the dangers that anhydrous ammonia poses.

Farm Safety With Anhydrous Ammonia (NH3) and Personal Protective Equipment (PPE)

Although each state has individual regulations on the storage and use of NH3, it’s your responsibility to consult with your local department of agriculture to understand codes and required protocols. Here are a few common safety practices when dealing with NH3 that can help you keep the risk of accidental exposure to a minimum:

Offer detailed training. Staff that will handle NH3 must be trained in how to work safely with this chemical. Consider folding this training into the routine you follow when you bring on new hires to the farm.

Personal protection equipment (PPE) every time NH3 is used. Because of the risks faced when working with NH3, employees need to know that full-body protection is required when this chemical is in use. Ensure that at least two industrial-sized, ammonia-filtering, full-face gas masks/respirators are in good condition present onsite and near the pressurized container and storage facilities. Safety organizations like the Occupational Safety and Health Administration (OSHA) have specific guidelines to follow when storing and handling anhydrous ammonia (Opens in a new tab) that need to be observed, even if it’s only used in ammonia refrigeration systems.

Nearby access to a SCBA system. A positive pressure self-contained breathing apparatus has to be in working order in the event of a life-or-death emergency when exposure to anhydrous ammonia is inevitable. It should be kept near workers whenever they are using anhydrous ammonia to ensure that they’ve got this life-saving system accessible to them when they need it.

Other worker-required personal protective gear. Protective NH3-impervious gloves and boots should be worn each time your employees handle NH3. Additionally, an NH3-impervious, protective slicker, pants and jacket need to be worn each time to protect the worker. They should also be instructed to wear a long-sleeved shirt.

Shower facilities. An easily accessible shower and/or 100 gallons of clean water in an open-top container should be readily available. The tank should be reserved for emergencies and not used for drinking water or any other purpose.

Material safety data sheet — posted. Clearly post a copy of the NH3 safety data sheet in a common area where employees can review it during breaks to learn about safety and health precautions. Emergency personnel and first responders may also need a copy of this document, so it’s wise to have a few other fact sheets handy.

Vented face shield. A set of flexible-fitting, hooded ventilation goggles plus a face shield should be provided for workers. Be aware that non-vented goggles are required when transferring NH3 from a storage tank to a nurse tank.

Accidental Release of Anhydrous Ammonia (NH3): Risk Management Programs and First Aid

If the eyes, nose, throat or areas of skin are exposed to NH3, the first response is to flush the exposed area for a minimum of 15 minutes. Here are a few more safety concerns when working with NH3:

Train on-site, dedicated responders. Assign a few well-seasoned employees to be your on-site responders to NH3 emergencies. They should know the standards outlined in your farm emergency management plan, and also what action should be taken, depending on the circumstances.

Transport vehicle leaks. If a leak should occur in transportation equipment and it’s not practical or possible to stop the leak, the driver should suit up with all required PPE and move the NH3 tank to an isolated location — downwind of any populated areas or heavily traveled roads and highways.

Safety measures on the farm and in the field. Workers spraying or transporting NH3 in the field should always carry an 8-ounce squirt bottle of water when working with any NH3 equipment in the event of accidental exposure to the skin. Applying water immediately after exposure can reduce the resulting chemical burn. Always wear gloves and non-vented goggles that meet ANSI Z87.1 impact specifications when connecting or disconnecting nurse tanks and applicators. Have a backup set of ammonia-impervious gloves, goggles, respirator with approved cartridge and 5 gallons of fresh water when applying or transporting NH3 nurse tanks. Remember that it’s vitally important to always work upwind of NH3 equipment.

Treatment for contact with the eyes. If the eyes should come into contact with NH3, flush thoroughly for 15 minutes. Do not use neutralizing solutions or ointments. Contact a physician immediately each time exposure to this chemical meets the eye.

When an NH3 leak occurs, having a risk management plan in place can help to ensure that quick action is taken. Here are some steps to follow in the event of a leak:

  • Evacuate any bystanders that are not directly involved in responding to the emergency.
  • Put on PPE.
  • Shut off appropriate valves.
  • Notify state and federal authorities as stated by local and state laws.

Managing Theft of Anhydrous Ammonia (NH3)

Another concern with NH3 is its use as an ingredient in the illegal production of methamphetamine. Theft of NH3 usually occurs with the loss of an entire tank, left overnight in the field. Here’s what you need to know to prevent NH3 theft.

Inspect your tanks daily. All tanks must be equipped with an approved locking device. Look for partially opened tank valves and or leaking tanks. If you see any items that may be left behind after a theft like buckets, coolers, duct tape, garden hoses or bicycle inner tubes, contact your local authorities.

Stay alert. Keep an eye out for the presence of unfamiliar or suspicious-looking individuals during daylight hours near the tank or close to your property in general. NH3 thieves typically scope out the area before a theft. Check in with other local farmers to see if they’ve experienced any thefts or suspicious activity so you'll know to be on the lookout. Together you can help keep one another informed.

With volatile chemicals in play, it’s important to know the risks and the best ways to manage them in order to work safely with NH3. Having a solid risk management program and response plan in place — if the unexpected should occur — can bring you some comfort knowing that you’ve done all you can to keep your operation safe. And carefully insuring your farm is a task that should be done mindfully, on an annual basis, to be sure that your inventory and risks match your production. Contact your American Family Insurance agent (Opens in a new tab) today to set up a meeting. You’ll have real peace of mind knowing your employees and your operation are covered.

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