Chemical Fire Risk in Ammonia Refrigeration: Lessons from the Koch Foods Fairfield Explosion

On February 15, 2026, an explosion and subsequent fire killed one worker and partially collapsed an Ohio poultry processing plant. The Koch Foods fire in Fairfield, Ohio is a sobering reminder of how fast a routine production day can turn into a high‑hazard event when industrial chemicals, refrigeration systems, and confined spaces are involved.

The fire’s heat was so intense it melted sections of the building’s steel structure and caused a large portion of the 600,000 sq. ft. facility’s roof to collapse. It took roughly 100 firefighters about seven hours to bring the blaze under control.

Due to concerns about a toxic anhydrous ammonia gas release, a two‑mile shelter‑in‑place order was issued for the surrounding community and lifted within approximately five hours. While the cause of the event is still under investigation, the plant used anhydrous ammonia for industrial refrigeration. Several outlets have reported that maintenance work was being conducted in or near the area where the fire began. It is not yet clear whether the explosion was directly caused by the ammonia system or whether the refrigeration system simply escalated and complicated the fire response.

For EHS and operations leaders in food, beverage, and broader industrial manufacturing, this incident underscores the need for rigorous chemical safety, mechanical integrity, and fire protection strategies around ammonia‑based refrigeration and other high‑hazard process chemicals.

Why Anhydrous Ammonia Is a High‑Hazard Chemical

While anhydrous ammonia is known primarily as an inhalation hazard, it can also drive explosions and secondary fires under specific conditions common to industrial environments such as food processing facilities and cold‑storage warehouses.

Ammonia is flammable when it reaches a concentration of roughly 15% to 28% by volume in air. If a leak occurs in an enclosed area—such as a processing room, engine room, or mezzanine with limited ventilation—the gas can quickly accumulate into this explosive range.

Once the concentration is within this “explosive envelope,” a relatively minor ignition source—electrical equipment, a forklift, hot work, or handheld maintenance tools—can be enough to trigger a powerful blast.

2. Factors That Increase Explosion Risk

Lubricating oils: In industrial refrigeration systems, ammonia often mixes with lubricating oils. This mixture can widen the effective flammability range, making the gas easier to ignite and potentially increasing blast energy if an ignition occurs.

Hydraulic shock: Rapid pressure changes or liquid slugs in the piping (for example, during defrost cycles or abnormal valve operations) can cause catastrophic pipe rupture, instantly releasing large quantities of ammonia into a confined space.

Decomposition at high temperatures: At very high temperatures—such as those present in a developed structure fire—ammonia can decompose into hydrogen gas, which is extremely flammable and highly explosive. This decomposition pathway can transform a toxic release scenario into a combined toxic, fire, and explosion event.