by Danaila Paspalanova, CHMM
image credit: www.bloomberg.com
When I think about the recent disaster at the West Fertilizer Co. plant in West, Texas the first thing that comes to my mind is—this was a ticking bomb that no one knew about. Was this tragedy preventable? What went wrong? Those are questions we all want to know.
While reading articles about the fire and subsequent explosion, I came across some very interesting facts which all lead to one conclusion: improper storage and improper reporting of hazardous materials.
After 9/11, in response to the growing awareness of the risk that chemical manufacturing facilities (as well as other facilities that store certain chemicals) may be potential targets for attack or theft, the U.S. Department of Homeland Security (DHS) passed the Chemical Facility Anti-Terrorism Standards (CFATS) on April 9, 2007. On November 20, 2007, DHS published Appendix A to CFATS providing a list of chemicals known as Chemicals of Interest (COI) and their threshold quantities. It turns out that last year the West Fertilizer plant had been storing 1,350 times the amount of ammonium nitrate that would normally trigger safety oversight by DHS. Filings this year with the Texas Department of State Health Services show the plant had 270 tons of it on hand last year. Per DHS, any facility that manufactures, uses, stores or distributes certain chemicals above a specified quantity listed on Appendix A has 60 days to complete and submit a CSAT Top-Screen. Facilities, such as the West Fertilizer plant, that manufacture, use or store chemicals above the threshold will then have a risk based tier level assigned. What shocked me while reading was that “DHS did not even know the plant existed until it blew up”.
SARA Tier II reports are forms that facilities in the US with hazardous chemicals above certain quantities are required to complete under EPA regulations. Known officially as Emergency and Hazardous Chemical Inventory Forms, Tier II Reports are submitted annually to local fire departments, local Emergency Planning Committees (LEPC) and State Emergency Response Commissions (SERCs) to help those agencies plan for and respond to chemical emergencies. Texas even has its own Tier II reporting. A facility can determine if it has chemicals in quantities that require Tier II reporting by checking the EPA’s List of Lists. However, if you look on the list, you will find that ammonium nitrate is not on it, although it is a strong oxidizing agent. Therefore, there was no reporting under EPA requirements which gives this information to the local first responders, which in this case suffered heavy fatalities as they fought the intense blaze.
However, after further reading, I found out that another chemical had been stored—anhydrous ammonia, which is on the EPA List of List and triggers reporting. Anhydrous ammonia is a widely used, efficient form of nitrogen fertilizer. When used in agriculture, it's compressed into a clear, colorless liquid and must be stored at extremely low temperatures. In its natural form, in the open air, it's a gas, so agriculturists use special equipment to compress and handle it, storing it in tanks that can withstand 250 psi. But outside of that tank, it quickly reverts back to its gaseous state. Properly trained emergency responders will not mix water used for firefighting directly with anhydrous ammonia, as this could result in warming of the product, causing the liquid to turn into a toxic vapor cloud. In addition, it can explode at extremely high temperatures.
This scenario became a disaster because a fire turned into an explosion. The key to avoiding disasters like this one is being prepared for the worst case scenario, which was obviously not the case here. This tragedy most probably would have been prevented if proper reporting was done and the local emergency responders had understood what they were dealing with (given the proper information) and had been properly trained to deal with this type of scenario. That determination will be made by officials investigating this disaster and the response.
There is a very useful and simple software tool available called WISER—developed to help Environmental Specialist and Emergency Responders assess such situations. Using WISER to respond to a fire dealing with ammonium nitrate or anhydrous ammonia they could have developed a worst case scenario and would have seen four scary words: EXOTHERMIC, EXPLOSIVE, FLAMMABLE, PRESSURIZATION.
Emilcott can assist with SARA and DHS reporting as well as the development of Emergency Action or Response Plans.
