What is anhydrous ammonia?
April 18, 2013 -- Updated 1308 GMT (2108 HKT)
- Anhydrous ammonia is a pungent gas with suffocating fumes
- Symptoms can include breathing difficulty; irritation of the eyes, nose or throat
- Exposure to high concentrations can lead to death
(CNN) -- Firefighters at the scene of a massive fertilizer plant explosion in Texas were concerned Wednesday night about anhydrous ammonia.
According to the Centers for Disease Control and Prevention, anhydrous ammonia is a pungent gas with suffocating fumes that is used as a fertilizer.
When exposed to humans, it can cause various problems:
• Anhydrous means without water
Watch fertilizer plant explode
Plant explosion devastates Texas town
Explosion aftermath 'like Iraq'
• Anhydrous ammonia can rapidly cause dehydration and severe burns if it combines with water in the body
• Symptoms can include breathing difficulty; irritation of the eyes, nose or throat; burns or blisters.
• Exposure to high concentrations can lead to death.
• Victims require treatment with large quantities of water for at least 15 minutes
• It must be stored at high pressure, according to the University of Minnesota.
• It is a low-cost, highly effective nitrogen-based fertilizer, the University of Arkansas said.
• It is one part nitrogen and three parts hydrogen.
• When released, the vapors initially move close to the ground, causing greater risk for exposure.
One of the worst disasters in U.S. history involving a form of ammonia occurred in April 1947 when a ship loaded with ammonium nitrate -- a solid fertlizer composed of ammonia and nitrogen -- caught fire while docked in Texas City, Texas, in April 1947. The fire caused an explosion that damaged more than 1,000 buildings, according to the website of the Texas Historical Association.
The blast ignited a fire on a second ship docked in Galveston Bay that was also loaded with ammonium nitrate. With most of the city's fire fighters killed in the first blast, the fire burned for 16 hours and caused another huge explosion. Volunteers fought to put out subsequent blazes.
The historical association said almost 400 people were killed and more than 175 were listed as missing. Only a few bodies in the dock area were even recovered.
Today's five most popular stories
Part of complete coverage on
Texas fertilizer plant explosion
April 17, 2014 -- Updated 1158 GMT (1958 HKT)
West, Texas, isn't just a town. It's a family.
At least 14 people, including nine first responders. The names of those that lost their lives are in our memorial interactive.
December 5, 2013 -- Updated 1514 GMT (2314 HKT)
A paramedic who responded to the deadly fertilizer plant explosion was sentenced to 21 months in federal prison for conspiring to make a pipe bomb.
April 26, 2013 -- Updated 0941 GMT (1741 HKT)
They were wives and brothers and fathers and grandmothers, and they were hurting.
April 27, 2013 -- Updated 2004 GMT (0404 HKT)
To really know West, you have to venture about half a mile east. There, past the Ole Czech Smoke House selling sausages and the flags flying at half-staff, the people tell the story.
April 26, 2013 -- Updated 1427 GMT (2227 HKT)
Two days after a deadly explosion ripped through the small Texas town, Sgt. W. Patrick Swanton found himself carefully picking through the debris of damaged homes looking for lost pets.
April 26, 2013 -- Updated 1628 GMT (0028 HKT)
Learn what you can do to help the people injured and affected by the explosion in Texas.
April 19, 2013 -- Updated 0307 GMT (1107 HKT)
As the sun rose, the small town's devastation came into fuller view: a gruesome, bloody scene, homes flattened to rubble, and scores of firefighters battling a raging blaze.
The explosion damaged buildings for blocks in every direction. Between 50 and 60 homes in a five-block area sustained damage, officials said.
April 18, 2013 -- Updated 1310 GMT (2110 HKT)
The blast was so catastrophic, it destroyed Marty Marak's home, killed his dog and leveled houses for blocks around.
April 18, 2013 -- Updated 1308 GMT (2108 HKT)
Firefighters at the scene of a massive fertilizer plant explosion in Texas were concerned Wednesday night about anhydrous ammonia.
April 17, 2014 -- Updated 0145 GMT (0945 HKT)
Click through photos documenting the explosion and its aftermath in West, Texas.
April 18, 2013 -- Updated 1257 GMT (2057 HKT)
Dr. George Smith describes what he went through when a fertilizer plant exploded in West, Texas. KCEN reports
April 18, 2013 -- Updated 0924 GMT (1724 HKT)
Watch video of the moment a burning West, Texas, fertilizer plant erupts in a massive explosion.