The recent devastation in Beirut, Lebanon, is a reminder of the explosive potential of large quantities of ammonium nitrate, and Missouri's emergency management agency said facilities in the state that store the substance are required to report large quantities of it.
That information is also to be shared with local fire departments and emergency planners.
Earlier in August, more than 2,700 tons of ammonium nitrate detonated at a warehouse in the port of Beirut - apparently caused by a fire in the warehouse where the material had been dangerously stored for years.
The blast from the explosion ripped through the city, killing hundreds of people, injuring thousands and making hundreds of thousands homeless, according to the Associated Press.
That disaster was the latest in a history of destructive ammonium nitrate explosions around the world and in the U.S., including in 1947 at the port of Texas City, Texas, and more recently in 2013 at a fertilizer plant in West, Texas.
In those incidents and in Beirut, firefighters who arrived on scene were particularly vulnerable, as they were closest to the danger while trying to put out the fires that ultimately detonated the ammonium nitrate on site.
Ammonium nitrate is used to make fertilizers, but it can also be used in explosives. The terrorist bomb used in 1995 to destroy the Alfred P. Murrah Federal Building in downtown Oklahoma City had ammonium nitrate as a component.
The substance does not readily burn "but will do so if contaminated with combustible material," according to the National Library of Medicine's summary of the chemical compound.
Caty Luebbert - public information officer with Missouri's Emergency Management Agency - said: "Ammonium nitrate generally is not considered dangerous in small quantities, such as those that would be found in the average garden shed in the backyard. Larger quantities that might be found in barns or storage facilities on larger farms or industrial facilities could pose an extreme danger if not stored or contained properly or exposed to certain conditions."
"Under extreme conditions with the presence of heat and pressure in a confined space, ammonium nitrate can explode," Luebbert said.
In addition to its explosion hazards, she said, ammonium nitrate is also a strong oxidizer that will cause other combustible materials such as wood, paper or oil to ignite; it's an inhalation hazard in high concentrations; and when mixed with water, it forms a mild acid that irritates eyes, noses and skin.
Beyond storage facilities, ammonium nitrate may also be present as cargo aboard train cars and truck trailers.
Whether a disaster be an accident or intentional, Luebbert said all incidents are studied, and training is adapted.
She said the Emergency Planning and Community Right to Know Act - a federal law - requires facilities and industries report on the locations and amounts of hazardous materials such as ammonium nitrate that are stored in significant quantities.
"Ammonium nitrate is considered a highly dangerous material in large amounts and would definitely be reported in storable quantities," Luebbert said.
That information has to be shared with local fire departments, local emergency planning committees and the Missouri Emergency Response Commission, she said.
"This information is also available to the community for a specific location," she added.
Jefferson City Fire Department spokesman Jason Turner said he could not think of any local facilities that store ammonium nitrate, and "if they do, it's below the threshold of what's reportable."
Turner added facilities that do have enough ammonium nitrate stored to report also have to placard-mark the building containing the material.
The chiefs or spokesmen of the Russellville-Lohman Fire Department, Osage Fire Protection District and Southern Boone County Fire Protection District also all said they were not aware of any facilities in their areas that store ammonium nitrate.
Russellville-Lohman Chief Mitchell Ott said: "Most of what we're going to have is small tanks (of other substances) leaking."
The Southern Boone fire protection district's spokesman, Barrett Glascock, said agricultural plants such as MFA have ammonium nitrate but not in large quantities.
The chief of the Regional West Fire Protection District did not immediately return a request for comment.
In terms of response training, Luebbert said: "The Missouri Emergency Response Commission and Missouri Division of Fire Safety are tasked with providing some up-to-date training involving very hazardous materials such as ammonium nitrate. How much training (first responders) receive would likely vary from department to department. But the point of the (federally-required) annual reporting is so that local agencies can assess the potential hazards in their communities and plan their preparedness level accordingly."
Osage Fire Protection District Chief Dennis Braun said his department has done some ammonium nitrate response training but not a lot.
Ott said it's been a while since such training has been done.
Glascock and Turner said their departments do hazard training.
Turner said the "all-hazards training" encompasses all types of fires.
Glascock said members who are also part of the fire departments in Jefferson City or Columbia share training they've done there and their mutual aid agreement with the Boone County Fire Protection District allows them to face emergencies they may not otherwise have experience with.
A 2015 chemical safety advisory by federal safety regulators and law enforcement recommended if a storage area where there's ammonium nitrate is already on fire, there's brown or orange smoke observed, or there's a rapid increase in the amount or intensity of smoke or fire in an ammonium nitrate storage area, firefighters and anyone else should immediately evacuate the area to be at least a mile away in any direction - or a distance determined safe by an emergency response plan.
A small fire involving ammonium nitrate or a fire that could spread to an area where ammonium nitrate is stored could be attacked with "flooding quantities" of water - and only water - from a distance and as promptly as possible, in an effort to keep quantities of ammonium nitrate cool, according to the advisory.