By now most people have heard about the fertilizer plant explosion in West, TX. CNN is reporting several (5-15) fatalities and over 200 injured. Located north of Waco, TX and approximately 75 miles south of Dallas, TX on I-35 and it has a reported population of 2,700 people. This information may be premature as reports are still coming in as of 0900 (CST) on April 18, 2013.
One emergency worker who had been reported as missing, a constable serving as a volunteer firefighter, has been found in a hospital with critical injuries. Three or four first responders, among the first to fight the fire before the fertilizer plant exploded shortly before 8 p.m. Wednesday, April 17, 2013 remain missing. And there is a confirmation that there are at least 2 emergency responders who received fatal injuries.
The plant is surrounded by homes and businesses which included a nearby apartment complex with about 50 units and a nursing home and a middle school that had been destroyed. Also there were between 50-75 homes that were destroyed.
According to eyewitnesses, “It was a small fire and then water got sprayed on the ammonium nitrate, and it exploded just like the Oklahoma City bomb.”
People as far as 50 miles away reported feeling what seemed like an earthquake. The U.S. Geological Survey reported that the blast generated enough force to register like a magnitude 2.1 earthquake.
One of the plants tanks had exploded and another was being monitored by emergency responders. A shelter in place order had been given to those who were not in the immediate area due to the leaks from tanks and piping the plants ruins.
The West Fertilizer Plant is an Anhydrous Ammonia plant and had a reported amount of over 54,000 pounds of the chemical on site before the explosion.
Ammonia, as used commercially, is often called anhydrous ammonia. This term emphasizes the absence of water in the material.
The proper name is UN1005 Ammonia, Anhydrous 2.3 (8) for international and a 2.2 for domestic (US) transportation. It is considered so corrosive to the skin that OSHA has mandated that anytime it is transported they are required to have 5 gallons of water to wash off any spills with. It is toxic by inhalation and causes severe respiratory distress. It is also a cryogenic liquid.
Anhydrous Ammonia is heavier than air and fills in depressions and as you can guess, under the right conditions highly volatile. During World War II, Belgium used it to power their buses.
Anhydrous Ammonia is not only used as a fertilizer, but as a commercial refrigerant for places like meat lockers and cold storage. It is also one of the main components for making Meth.
It was listed in the 49 CFR 172 Appendix A, Subpart B as a Hazardous Substance with an RQ of 10 lbs. But farmers have a strong lobbying group (hence the 2.2 domestic classification) and in this case it makes sense to have it removed from the table as they were putting it in the ground anyway. That does not alleviate the fact that there will probably be some long term, chronic health issues in the future.
The U. S. Occupational Safety and Health Administration (OSHA) has set a 15-minute exposure limit for gaseous ammonia of 35 ppm by volume in the environmental air and an 8-hour exposure limit of 25 ppm by volume. NIOSH recently reduced the IDLH from 500 to 300 based on recent more conservative interpretations of original research in 1943. IDLH (Immediately Dangerous to Life and Health) is the level to which a healthy worker can be exposed for 30 minutes without suffering irreversible health effects.
Anhydrous ammonia is a colorless, highly irritating gas with a sharp, suffocating odor. People will notice the pungent odor at levels ranging from 5 – 50 parts per million (ppm). Irritating effects generally begin at levels between 25-50 ppm. More serious effects generally will not occur until levels are greater than 100 ppm. Anhydrous ammonia can rapidly cause dehydration and severe burns if it combines with water in the body.
Immediate health symptoms include: burning of the eyes, nose, and throat after breathing even small amounts. With higher doses, coughing or choking may occur. Exposure to high levels of anhydrous ammonia can cause death from a swollen throat or from chemical burns to the lungs. Eye exposure to concentrated gas or liquid can cause serious corneal burns or blindness.
Generally, the severity of symptoms depends on the degree of exposure. Most people recover from a single low exposure to anhydrous ammonia without any delayed or long-term effects. After a severe exposure, injury to the eyes, lungs, skin, or digestive system may continue to develop for 18 to 24 hours, and delayed effects primarily to the respiratory system or the eyes are possible.
Anhydrous Ammonia is not known to cause cancer.
There may be a white powder residual left over after it dries. This substance is ammonium hydroxide and occurs after anhydrous ammonia settles out after exposure to water. It is similar to the ammonia used in general home cleaning. This needs to be washed off with soap and water.
This information was secured from the ND Dept. Of Health, the University of MN, OSHA and the US Dept. of Health.