Firefighters were forced to back away from flames at a fertilizer plant near West, Texas late Wednesday over fears surrounding anhydrous ammonia on the scene.
The plant exploded in the community near Waco after crews were called to help extinguish a small blaze.
Witnesses said the flames came in contact with water, resulting in the explosion.
When anhydrous (meaning without water) ammonia contacts water, the two combine quickly, the University of Minnesota website says.
“Anhydrous ammonia is caustic and causes severe chemical burns,” the website says.
“Body tissues that contain a high percentage of water, such as the eyes, skin, and respiratory tract, are very easily burned. Victims exposed to even small amounts of ammonia require immediate treatment with large quantities of water to minimize the damage.”
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It’s popular among farmers because it is effective, readily available and easily used as nitrogen fertilizer, said David E. Baker of University of Missouri-Columbia.
Anhydrous ammonia is a chemical made of one part nitrogen and three parts hydrogen that must be stored at high pressure.
The colorless gas has a “sharp penetrating odor” that offers early warning, according to Baker.
“You can’t stand to breathe it,” Baker writes online. “When people receive burns or eye damage from the product, it is because of a sudden release of it where the victim is unprotected and cannot escape.”
The chemical can also be used as a refrigerant, the Centers for Disease Control website says.
In its liquid state, if it’s released into the atmosphere is can form a cloud that can be fatal in larger concentrations.
Most injuries occur when the gas is released quickly and victims can't escape.
Anhydrous ammonia is also used in producing crystal meth, making it a popular target for thieves.
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