DEKRA Process Safety Alert: Ammonium Nitrate Hazards
Understanding Ammonium Nitrate Hazards
The explosion that occurred in Beirut on August 4, 2020 appears to be another example of the detonation hazards of Ammonium Nitrate (AN). Since 2010, similar explosions have devasted communities like Tianjin, China and West, Texas.
Pure ammonium nitrate is stable. It can decompose explosively when exposed to elevated temperatures (as in a fire) or becomes contaminated. AN is an oxidizer, so while not combustible itself, it will accelerate the burning of combustible materials and create rapid fire growth.
A Confusing Regulatory Patchwork
Ammonium Nitrate is principally used as an agricultural fertilizer, but OSHA regulates storage through 1910.109, the Explosives and Blasting Agents Standard. This leads to end users frequently overlooking requirements. Despite its well-known hazards, AN is not regulated by OSHA Process Safety Management (PSM) or EPA’s Risk Management Plan (RMP).
Risks to Emergency Responders
Explosions involving AN have occurred for more than 100 years, and they unfold with shocking similarity. Typically, the explosion is caused when a fire in a different part of the facility spreads to the storage location, heating the material. This scenario offers about 30 minutes before an explosive decomposition chemical reaction occurs – typically just the right amount of time for workers to evacuate but allows firefighters to respond to the blaze. In 1947, such a scenario killed 581 people, including all but one member of the Texas City Fire department.
Ammonium Nitrate Isn’t Alone
AN isn’t the only reactive hazardous material that presents significant risk in a fire scenario. Warehouses, shipping companies, and agricultural supply firms need to understand reactivity and fire hazards and take action to protect our communities. There are many things to consider, but these stand out:
- Know the decomposition and reactivity hazards of chemicals marked as oxidizers, flammable solids, “poisonous gas under pressure,” and “dangerous when wet.” If you don’t know how the material will respond in a fire, submit it for testing.
- Do not ship or store incompatible materials next to one another. Also verify that the facility, container, and shipping practices meet codes and standards for handling hazardous materials.
- Confirm that material is stored in approved areas and that the bulk material being used in the structure meets the occupancy permit approved by local fire authorities. Ensure the local fire department is trained on the hazards at your facility.
Leaders: Say Something, Do Something
Do not wonder if you are doing enough to manage risk. Take necessary steps to educate yourself and manage the risks in order to protect the lives of your workers, the community, and our emergency responders.
Resources that may help include:
- OSHA memo to fertilizer industry (including linked resources)
- CCPS Reactive Material Hazards Guide
DEKRA is offering a complimentary 15-minute discussion to help companies navigate the storage and transport of ammonium nitrate or other hazardous materials in the effort to protect workers and the community. Please call (609) 799-4449 extension 321 or contact us referencing this offer.