Tag Archives: fertilizer

Deadly Explosion at Texas Fertilizer Plant

By ThinkReliability Staff

An explosion at a fertilizer plant in West, Texas, destroyed much of the town and killed between 5-15 people.   (Search and rescue is still ongoing.)  At least 160 were injured but that number may increase.  The material involved in the explosion was ammonium nitrate, a popular fertilizer.

Capturing the impacts to the goals as a result of an issue is essential to understanding the true effect.  In this case, the fatalities and injuries were severe.  The property damage, which included the plant, as well as the homes of more than 100 families, was also extensive.  An environmental impact resulted from the release of ammonia, which is a respiratory irritant. There was some level of evacuation, which can be considered an impact to the customer service goal, though the high number of injuries has led some to believe the evacuation was not widespread enough.  Additionally, ongoing search and rescue, and firefighting operations are an impact to the labor goal.

These goals were all impacted due to the explosion at the fertilizer plant.  Ammonium nitrate can explode when ignited at very high temperatures.  In this case, a fire provided the high heat.  We can capture these causes in a Cause Map, or a visual form of root cause analysis.  The cause of the fire itself is as yet unknown, though if that is determined we can add it to the Cause Map as well.

What is known is that efforts to prevent explosion were ineffective.  The plant did not believe that an explosion was possible.  Its internal safety review had a worst-case scenario of a ten-minute ammonia release, causing no injuries.  It is fairly rare that ammonia nitrate explodes; only 17 known cases of unintended ammonia nitrate explosions resulting in fatalities have occurred since 1921.  Firefighters were on scene fighting the fire when the explosion occurred, leading to many responder fatalities and injuries.  Oversight at the facility was limited; OSHA has not inspected the facility for at least the last five years.

It is worth exploring why large amounts of ammonium nitrate were present.  Ammonium nitrate is an inexpensive, effective fertilizer.  It is particularly good at delivering nitrogen to food-bearing plants, like fruit trees.  The use of nitrogen greatly increases the yield of food from these plants.  (It is said to increase the carrying capacity, or number of people who can be supported by a hectare of land – from 1.9 to 4.3.)  Given the shortage of food-growing land, this is certainly important.   However, the benefits must be considered alongside the risk and certainly in the future more oversight of these types of facilities may be needed to protect the public from the process as they benefit from the results.

To view the Outline and Cause Map, please click “Download PDF” above.