April 25, 2019—It was a cool and humid morning in Beach Park, Illinois. The air was calm. At about 4 am, a tractor made its way down a main 2-lane county road, towing a pair of 2-ton anhydrous ammonia tanks behind it. Suddenly, the tanks started leaking. The tractor stopped working. A large plume of white gas began to form, settling low and lingering in the area, where it covered the road and surrounded nearby homes.
The first 911 call came in at about 4:30 am, reporting a crash—the cloud of ammonia mistaken for smoke from a vehicle fire. Two deputies from the Lake County Sheriff’s office arrived at the scene and were quickly overcome by the fumes. They retreated, and firefighters initiated a hazmat response.
Authorities issued a shelter-in-place order by 5:10 am for all residents within a 1-mile radius of the scene, also advising homeowners to close their windows and turn off their HVAC systems.
It was motorists in the area who were at the highest immediate risk, however. Upon encountering the toxic cloud, their vehicles stalled. They were effectively trapped in the deadly gas with nowhere to go.
More 911 calls started rolling in.
“Oh, God, it’s horrible. I can’t breathe,” said one motorist who called 911 after her vehicle stalled. “I got to get out of the car. Oh it’s terrible.”
Firefighters wearing protective gear rescued stranded drivers and passengers. They also responded to calls in the area from residents who reported feeling symptoms of ammonia exposure. First responders started going door to door in the area, asking residents if they had their windows open in the early morning and if they were feeling alright.
The shelter-in-place order was lifted at approximately 10 am.
81 people were treated at local emergency departments for symptoms related to ammonia exposure. 14 were hospitalized in critical condition.
According to a CDC report on the incident, at least 500 gallons of anhydrous ammonia leaked from those tanks. Weeks after the plume had dissipated, blackened trees lined the county road where the spill had occurred. Homeowners’ lawns turned from green to black.
What Is Ammonia & Where Is It Found?
A colorless, poisonous gas with a distinctly noxious odor, ammonia is the ninth-most produced chemical on the planet. In 2020, worldwide ammonia production reached over 206 million tons. Concentrated ammonia is used in manufacturing, refrigeration, and making fertilizer. It is also found in many household and industrial cleaning products.
Ammonia also occurs naturally and can be found throughout the environment in the air, water, soil, and all living things. In nature, it is primarily produced by anaerobic decay (decay where there is no oxygen present, such as in waterlogged soils or marshes). Ammonia has even been detected in outer space.
What Happens When People Are Exposed to Ammonia
Ammonia is highly toxic and can cause severe injuries or even death if a person is exposed to it. The manner of exposure, the concentration of ammonia, and other factors may affect how serious a person’s injuries are.
Dermal (Skin) Exposure
Liquids containing ammonia at concentrations of less than 5% are unlikely to cause serious harm, although they can be irritating. Exposure to concentrated ammonia vapor, however, can cause intense pain and inflammation, blisters, and deep, penetrating burns—particularly on areas of the skin that are moist. If one’s skin comes into contact with compressed, liquid ammonia, which is stored at -28 °F, frostbite, burns, and ulcers may occur.
Ocular (Eye) Exposure
Ammonia is one of the most damaging chemicals to the eye. Even at low concentrations, ammonia vapor can cause immediate eye irritation, and highly concentrated ammonia vapor can cause temporary or permanent blindness.
Exposure by Ingestion
Although less likely than other forms of ammonia exposure, ingesting even household ammonia can cause serious burns in the esophagus. Ammonia can perforate the esophagus or stomach, the symptoms of which may include chest pain, abdominal pain, and abdominal stiffness.
The most common and deadliest form of ammonia exposure is inhalation. Even in relatively low airborne concentrations, ammonia can quickly cause eye, nose, and throat irritation. Coughing and narrowing of the bronchi (the major passages of the lungs) will soon follow. Swelling and narrowing of the throat can make it difficult to breathe, and fluid may begin to accumulate in the lungs. This can lead to low blood oxygen levels, altered mental state, unconsciousness, and respiratory arrest.
The people of Beach Park, including emergency responders and motorists driving through, were exposed to ammonia through inhalation. The noxious cloud was so thick that it stopped the motors in their cars, and they immediately felt the symptoms of breathing in the poisonous gas.
If they had not been rescued and treated, they would have died.
Who Is At Risk of Ammonia Exposure?
People at the highest risk of ammonia exposure are those who work with or near the chemical.
- Agricultural workers
- Oil refinery workers
- Miners and metal workers
- Those who work near or with commercial refrigerants, such as in food processing, ice production, and cold storage
- Industrial workers at plants and facilities that manufacture fertilizers, plastics, solvents, rubber, nitric acid, synthetic resin, and other chemicals
Incidents of workplace ammonia exposure are more common than one may think.
January 19, 2022—50 workers were evacuated and 2 were hospitalized after an ammonia leak at a Canton, Georgia poultry processing plant. The incident was linked to improper temperature and pressure conditions at the facility’s ammonia refrigeration system, resulting in liquid and vapor ammonia being released into the air.
August 11, 2022—A leak of more than 5,000 pounds of liquid anhydrous ammonia sent 7 bakery workers to the hospital in Brownsburg, Indiana. Overcome by fumes, all workers at the bakery were evacuated and treated at the scene by paramedics, complaining of headaches and shortness of breath.
October 25, 2022—Emergency crews in Wichita, Kansas responded to reports of a chemical leak at a manufacturing facility that makes parts for the aerospace industry. The chemical was identified as ammonia, leaking from a tanker trailer parked near the facility. The building was evacuated, and three workers experienced minor illnesses due to exposure to the toxic gas.
Even truck drivers who transport ammonia may be at risk of exposure if they are involved in a traffic accident or if there is a defect with the tank they are hauling.
One of the worst ammonia disasters in American history happened as the result of a truck accident in Houston, Texas. On May 11, 1976, a tanker truck carrying 7,500 gallons of anhydrous ammonia overturned, crashing through a freeway guardrail onto a ramp below. The truck collided with a cement column on the way down and the tank burst open, releasing ammonia into the air. A thick cloud covered the area. The accident itself claimed 1 life, and 5 others died from ammonia inhalation at the scene.
In total, 178 people suffered harm from ammonia exposure; 78 were hospitalized.
This brings about another issue related to ammonia exposure. Even people who do not work with or near ammonia could be exposed if there is a leak or spill, as happened in Beach Park, Illinois, and on that Houston roadway so many years ago. People living near plants where ammonia is used or stored could be in danger of suffering serious harm if there is a leak or explosion.
Explosive Hazards of Ammonia
Ammonia leaks are not the only concern when it comes to this dangerous gas. Ammonia gas can be compressed into a clear liquid under pressure. It is usually shipped in this way, as a compressed liquid in steel containers, and although ammonia is not considered highly flammable, in its pressurized state, it can present an explosive hazard. This is particularly true in confined spaces.
What Can Be Done to Prevent Ammonia Exposure
The companies that work with, store, and transport ammonia have an obligation to protect their workers, drivers, and nearby communities from the disastrous results of a leak or explosion.
Ammonia is known as a highly hazardous chemical and should be treated as such. All workers should be trained on the hazards ammonia can pose, the symptoms of exposure, and what to do if a leak occurs. Exit signs must be clearly marked so workers can evacuate if needed.
Employers are also required to maintain reasonably safe workplaces. When it comes to ammonia, that means the gas must be stored properly, and all equipment and processes requiring ammonia be properly inspected and maintained on a regular basis.
OSHA has strict regulations regarding the storage and handling of anhydrous ammonia. These cover every aspect of storing ammonia, including how containers are marked, how thick they must be, where they can be stored, pressurization, piping, hoses, and more. There is detailed information about safety-relief and shutoff valves, how liquid ammonia should be transferred, how it should be transported, and more. All of these regulations are in place to ensure the safe storage and transportation of ammonia; violations can prove disastrous.
After the January 2022 ammonia leak at the poultry processing plant in Georgia, OSHA investigated and proposed $110,630 in penalties against the plant owner based on its findings. Among the nine serious citations found in the investigation were failures to train workers on the hazards of ammonia, failures to maintain safe walkways and working surfaces, and failures to complete a safety review before introducing ammonia into an existing process at the plant. Not only could the incident have been prevented in the first place had the plant operator implemented proper procedures for introducing ammonia, but a lack of clearly marked exits put workers on-site at a higher risk of exposure: the liquid and vapor ammonia engulfed the emergency exit doors.
The 1976 tanker truck accident in Houston was attributed to two causes. First, the truck operator was driving too fast for current conditions. Second, the tank was not full, which meant that the anhydrous ammonia had space to move around. The National Transportation Safety Board (NTSB), which investigated the incident, presumes that the ammonia moved violently from side to side in the truck, causing it to overturn and careen off the overpass. Not only should the truck have been properly loaded, but the driver should have been warned of the danger that the partially full tank posed to the truck’s maneuverability.
What do these and all ammonia accidents have in common? They could have been prevented.
It’s time for companies to step up and put safety first. Not just for their workers, but for everyone that could be impacted by an ammonia leak.