The least expensive form of nitrogen also has the potential to be one of the most dangerous chemicals used in agriculture today. However, anhydrous ammonia can be used safely if the product is handled and applied correctly.
Those who work around the nutrient need to be properly trained to follow exact handling and transportation procedures. Using personal protective equipment (PPE) is another important aspect of working with the fertilizer.
These were some of the important points covered in a March 30 webinar titled “Anhydrous Ammonia Safety for Farmworkers” put on by the Agri-Safe Network. (here)
1. KEYS FOR WORKING WITH ANHYDROUS
Director of the National Education Center for Agricultural Safety (NECAS) Dan Neenan said the basic keys for anhydrous safety are proper training, respect for the product, wearing PPE and just to slow down when working with the fertilizer. Neenan is also a paramedic, firefighter and vice-chair of the Dubuque County Emergency Management Commission. NECAS is located in Peosta, Iowa.
Anhydrous is used and stored under high pressure, which requires specially designed and well-maintained equipment: A sudden rupture of a storage tank can shoot anhydrous 10 to 20 feet from point of release, he said.
The word “anhydrous” is taken from the Greek “an” — meaning “without” — and “anudros” (hydrous) meaning “water.” Anhydrous actively seeks water; in an accidental release, living tissue is dehydrated quickly and cells are destroyed on contact, Neenan explained.
Even lower-level releases (50 parts per million) is detectable to most people with no injuries. Levels at 134 ppm cause nose and throat irritation. Higher levels of 1,700 ppm can lead to serious lung damage or death.
“In an uncontrolled release, you need to run and/or drive into the wind to escape the cloud of anhydrous,” Neenan stressed.
2. DANGERS OF AA EXPOSURES
The subzero temperature of anhydrous causes a chemical burn; the skin is killed and not able to heal or replace itself. Damaged tissue must be removed surgically, and exposure to anhydrous is often disfiguring, Neenan said.
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The eyes are continually moisturized, so they are another body part susceptible to anhydrous burn. Burns to the eyes will cause damage, including cataracts, glaucoma and possibly permanent vision loss.
“Don’t wear contacts when working with anhydrous,” he said. “They can be welded to your eye if exposed.”
The lungs are another target anhydrous will seek and damage in an accidental release. Much like the eyes, the lungs are very moist; fertilizer will attach to them and burn the respiratory system very quickly, he said.
Neenan said people exposed to anhydrous need to immediately flush the affected area with large quantities of water. Those who work with anhydrous should carry with them at least a 6- to 8-ounce squeeze bottle with fresh water at all times, he said. This small amount of water will only last long enough to get to larger quantities of water.
3. HOW TO DRESS TO REDUCE INJURIES
Well-maintained PPE reduces the chances of injuries from working with anhydrous, Neenan said. This equipment should include unvented goggles or full-face shield, rubber gloves, respirator, heavy-duty long-sleeved shirt, long pants and non-porous aprons and sleeves.
Unvented goggles must be used to keep anhydrous away from the eyes, as vented goggles will allow the product direct access, he noted. Glasses should be worn under the goggles and, again, contacts should not be worn.
Gloves could be rubber or non-rubber material impervious to anhydrous and should be chemical resistant, Neenan said. These should have long cuffs to be able to fold back and prevent drips into your arms.
Gloves should fit loosely enough to put on and take off but be snug enough for good protection. Wash gloves after use and replace any cracked gloves.
“I always cut the fingers off the old gloves to prevent someone from taking them and using them again,” Neenan said.
4. OTHER PPE FOR PROTECTION
Respirators with anhydrous cartridges can prevent lung damage only for low-level exposure, under 300 ppm. This equipment should be well-maintained and cleaned regularly.
Respirators should be fit-tested annually, he said. Facial hair does not allow a tight fit; people working around anhydrous and using PPE need to be clean-shaven.
Neenan said women who work with anhydrous have issues locating PPE that will fit them properly. Since women have a different body structure than men, equipment such as respirators does not fit safely.
Employers’ limited knowledge of PPE design for women is often a big reason for this issue, he said.
5. KNOW AA EQUIPMENT
Neenan said those who work with anhydrous ammonia should fully understand the equipment used to transport and apply the fertilizer.
He suggested people do a pre-transport safety check by walking around the nurse tank. Make sure tires are good, lug nuts are tight and the safety clip in the hitch pin is present. The safety chains should also be crossed and secure.
Nurse tanks must only be hauled two at a time, and the length cannot exceed 75 feet, he said. The speed limit is 25 miles per hour, and with increased weight, there should be increased stopping distance.
People should also closely examine the anhydrous applicator. Worn components such as hoses, valves and fittings should be immediately replaced.
Knives should be closely looked at to see their condition. Also, check if they are plugged.
The regulator of the applicator should be secure and mounted on the implement level. The hydraulics of the applicator should also be in good working order, he said.
DTN writers have written several articles and blogs on anhydrous ammonia safety over the last two years.
Russ Quinn can be reached at email@example.com
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