10 Aug, 2020

In light of the recent tragedy in Beirut, Jeremy Lebowitz, Jensen Hughes’ Vice President Development, explores the causes of an ammonium nitrate explosion and how to prevent an incident.

Officials are just beginning to assess the damage in the port warehouse district of Beirut, Lebanon following the devastating explosions earlier this week. The explosion was felt in Cyprus, 240 km away. While the cause of the explosion is still unconfirmed, Lebanon’s interior minister has reported that 2,750 metric tons of ammonium nitrate likely caused the blast. It is clear, however, that the scale of destruction is massive.

What Makes Ammonium Nitrate Explode?

Ammonium nitrate is primarily used as a fertilizer and as a feedstock for commercial explosives. It is also a powerful oxidizer and a rich source of nitrate, which provides energy to an explosion. The storage of the chemical can increase or decrease its sensitivity to fire. To turn ammonium nitrate from a stable compound into an explosive, without any fuel or external catalyst, specific circumstances are needed. For instance, if the ammonium nitrate is exposed to combustible materials, it can quickly accelerate their flammability. It can also undergo explosive decomposition when heated in a confined space.

How Can Another Explosion Be Prevented?

After the West Fertilizer Plant explosion, the NFPA 400, Hazardous Materials Code, underwent some rigorous updates. The latest version called for new ammonium nitrate storage facilities to be of non-combustible construction, with separation of the material from contaminants, as well as automatic fire sprinklers and a one-hour fire barrier floor to roof required. They also imposed additional safeguards when a facility exceeds 500 kg.

To meet these requirements, the first step is to understand whether you are over the maximum allowable limits of a chemical, such as ammonium nitrate, by taking an inventory of all the chemicals stored in your building. Knowing the hazardous materials in storage and in use is a prerequisite to identifying the hazards present in your facility and protecting your employees and the public. Once the materials and their hazard classes are known, the thresholds for various building and process protection systems, such as fire sprinklers, ventilation and secondary containment, and subsequently personal protective equipment (PPE) needs, can be determined and applied.

Whether dealing with a new or existing building, there are valuable lessons to be learned from the Beirut tragedy. The most important of them all is to understand the nature of chemicals stored in your building and to make sure your building is properly designed for the hazards those chemicals can create. HazAdvisr is a cost-effective hazardous material inventory database and design platform that can establish whether your facility is safe and compliant. With our team of engineering experts, we can help design safety measures appropriate to your facility to prevent an explosion from occurring