Howard
J. Doss
Michigan State
Anhydrous
ammonia is one of the most efficient sources of nitrogen fertilizer
and is popular among Michigan growers because of its relatively
low price. With proper precautions, it is safe to handle,
but the number of accidents related to anhydrous ammonia in
the United States has increased in recent years. These increases
are due, in part, to older transport and application equipment
becoming timeworn.
Safety
devices built into anhydrous ammonia application equipment
are designed to protect against a major ammonia release, but
equipment failures have been reported. Operators and anyone
in the area are at risk for severe burns.
The
biggest risk associated with anhydrous ammonia handling is
an accidental release of NH3. Inside the tank,
ammonia under pressure remains in a liquid form that maintains
a temperature of -28° F. Once released, whether into the
soil or the air, it immediately becomes a vapor that seeks
out the most available source of moisture. Unfortunately,
this moisture source may be the body of the operator, which
is composed of 90 percent water. When a human body is exposed
to anhydrous ammonia the chemical freeze burns its way into
the skin, eyes or lungs.
Unlike
wounds from a fire which tend to sear the flesh, ammonia consumes
six times its own weight in moisture from any body tissue
available. The only treatment is water, lots of water, and
then more water. Flushing the burn with water gives the ammonia
an easier source of moisture to seek out, pulling it away
from human tissue. The best advice to ensure the safety of
the operator is to make sure the equipment is in sound operating
condition and, in the event of an accident, take every precaution
to protect against a serious injury by wearing basic personal
protective equipment (PPE).
Most
injuries occur when anhydrous ammonia is transferred from one
tank to another. It is during this task that operators frequently
forget to take the proper safeguards to reduce the risk of injuries
from ruptured hoses, valve or coupler failures, or any host
of problems that can happen in a split second. Without proper
protection, the operator is defenseless. Skin burns are the
most common injuries reported from accidental exposure to anhydrous
ammonia, but eye injuries are the most serious. To protect the
eyes, wear goggles specifically designed for handling anhydrous
ammonia. There are several brands available on the market that
offer the protection needed in the event of an accident. Don't
rely on eye- or sun-glasses to protect your eyes, the open area
between the eye and the frames allow anhydrous ammonia to come
in contact with the skin and eye tissue. Recommended goggles
are non-vented to keep NH3 vapors from the eyes.
These goggles fit tight but allow for wearing of eyeglasses.
Loose
fitting rubber gloves designed for anhydrous ammonia will
protect the hands from thermal freeze burns. Turn the cuffs
of the gloves out so liquid ammonia doesn't run down your
sleeve. Also, wear a heavy, long-sleeved workshirt to keep
the chemical from reaching the skin. Long pants with the cuffs
outside the boots are necessary for protection of the lower
body.
University
research shows that in 80 percent of the accidents involving
anhydrous ammonia, 80 percent of the workers had access to
gloves, but only 29 percent were wearing them. Likewise, 60
percent had goggles, but only 22 percent were wearing them.
Two
or more sources of water are recommended in case of an accident.
State law requires that all anhydrous transport and application
equipment carry a 5-gallon container for fresh water. This water
must be changed daily because anhydrous fumes that escape the
nurse tank will contaminate this water supply.
A small
squeeze bottle filled with clear water can be kept in your
shirt pocket. This bottle will readily available for flushing
anhydrous ammonia from your eyes or for rinsing small exposures
to the skin.
A third
water container, carried on the tractor, is a readily accessible
source of water for any accident. It becomes extremely important
if an ammonia leak prevents the operator from getting to the
water tank on the nurse tank.
If ammonia
gets on your skin or in your eyes, flush the areas with clear
water for at least 15 minutes to rinse away all ammonia. If
water is not available, cool coffee, milk, cola, juice or
other nontoxic liquid may provide temporarily help. An ammonia
blast to the face could freeze eye lids closed. Never force
eye lids open with your fingers, instead, apply water to the
lids and continue flushing until they open. When ammonia is
sprayed on your clothes, flush the clothing with water for
a few moments until it is thawed, then remove the clothing
and continue to rinse the skin for at least 15 minutes.
Always
seek medical attention after an exposure to anhydrous ammonia.
Proper medial treatment will reduce the severity of the injury
and speed the recovery process. Never apply salves or ointment
to ammonia burns. Your physician will advise you on the proper
treatment of anhydrous ammonia burns.
Disclaimer
and Reproduction Information: Information in NASD does not
represent NIOSH policy. Information included in NASD appears
by permission of the author and/or copyright holder. More
NASD Review: 04/2002
Michigan
State University, Agricultural Engineering Department.
Howard
J. Doss, Agricultural Safety Specialist, Michigan State University
Extension, East Lansing, Michigan 48824. 5/93. Funded by the
National Institute of Occupational Safety and Health - #UO5/CC-4506052-02.
This information is for educational purposes only.
|
