Anhydrous Ammonia Safety

Anhydrous ammonia is one of the most efficient and widely used sources of nitrogen for plant growth. The advantages of ammonia's relatively easy application and ready availability have resulted in a large increase in its use as a fertilizer on Missouri farms.

Anhydrous ammonia also has disadvantages especially in its handling. It must be stored and handled under high pressure, which requires specially designed and well-maintained equipment. In addition, to ensure operator safety, workers must be trained to handle this product and to follow strict work procedures.

Anhydrous means without water. Consequently, when anhydrous ammonia contacts moisture, they rapidly combine. When it is injected into the soil, the liquid ammonia expands into a gas and is readily absorbed in the soil moisture. Similarly, the liquid or gas that contacts body tissue (especially the eyes, skin and respiratory tract) will cause dehydration, cell destruction and severe chemical burns. Victims exposed to even small amounts of ammonia require immediate treatment to avoid permanent injury.

For use as an agricultural fertilizer anhydrous ammonia is stored in a liquid state, under pressure in specially made tanks strong enough to withstand internal pressures of a minimum of 250 pounds per square inch. Due to the corrosive nature of this product to many metals the tanks are made of high-strength steel or other suitable material and fittings should be made of black iron.

Due to its properties and the manner in which it is stored, anhydrous ammonia can create a dangerous situation when accidentally released. The following are some examples of how the misuse of anhydrous ammonia and its equipment can result in accidents:

• Filling tanks beyond recommended capacity.
• Knocking open the hose-end valve accidentally.
• Venting pressure release valve while a person is in line of discharge.
• Breaking of transfer hose, especially an old or misused one.
• Failing to bleed hose coupling before disconnecting.
• Rupturing of low pressure hose due to pressure bulild up when knives plug.
• Releasing ammonia when knives are unplugged.
• Overturning an applicator or nurse tank while in transit or in the field.

A face shield or goggles, rubber gloves and a heavy-duty long-sleeved shirt are recommended as minimum protection for operators handling ammonia. Wear gloves and eye protection whenever you are working on or operating anhydrous equipment or handling hoses.

It is important to wear properly fitting goggles or a face shield when working with ammonia. A face shield will help prevent inhalation of a direct blast of ammonia and will also reduce possible eye exposure. Regular glasses do not provide adequate protection. Never wear contact lenses when working with Ammonia. It might get under the lenses and cause permanent eye damage before you can remove the lenses and flush your eyes with water.

You can further protect yourself by wearing rubber gloves and heavy clothing when working with ammonia. If you store bulk quantities of anhydrous ammonia on your farm, you'll need additional protective equipment. Keep two rain suits or slickers and gas masks with an ammonia canister filter available for emergency work. When a serious leak occurs, call your local fire department for assistance. Firefighters have the proper training and equipment, including self-contained breathing apparatus and protective suits to deal with major ammonia leaks where high concentrations are probably present.

Seconds are critical when someone is sprayed with liquid ammonia or engulfed in concentrated vapors. When ammonia contacts the skin or eyes, tissue damage occurs rapidly. Immediate use of water to flush the exposed body areas is crucial. Regulations require that all farm vehicles used for anhydrous ammonia carry a container filled with at least 5 gallons of water. The water must be readily available for flushing the eyes and skin in case of exposure. The water should be changed daily to remain fresh. You should also carry a 6-8 ounce plastic bottle of water for eye wash in your shirt pocket.

In the event of contact with anhydrous ammonia flush the contacted areas thoroughly and get medical treatment immediately. For more detailed safety facts each operator and family member should obtain and read MU Agricultural Guide 1920 - "Using Agricultural Anhydrous Ammonia Safely."

For more information on this or other subjects visit the University Extension Center in your county, call me, Dr. Don Smith, at (660) 727-3339, or visit the Clark County University of Missouri Extension Internet Web Site at http://outreach.missouri.edu/clark/ for publications online. University of Missouri Extension programs and services are open to all and most are free or at a nominal charge.

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