Unraveling the actual safety benefits of adding inorganic fillers to ammonium nitrate

Abstract. Provided that ammonium nitrate-based fertilizers are stored and transported according to good practices and applicable regulation-driven requirements, no special safety concerns are expected. However, the explosion in Beirut in the summer of 2020 proved all lessons had not been learned from past disasters. It caused all concerned with ammonium nitrate (AN) to review current knowledge and mandatory practices in AN-based fertilizer storage. As France is the largest market in the European Union for high dosage (HD) AN-based fertilizers, questions arose as to the relative safety requirements posed on medium dosage (MD) and (HD) AN. The study reported herein seeks to go beyond a subjective comparison of these and quantitatively evaluate the performance of these fertilizer formulations. Our collaborative approach has combined officially recognized tests in applicable regulations and added a series of rate stick detonation tests. This study provides the disappointing proof that diluting AN, whether with calcium carbonate or sulfate, is providing no more safety than the dilution factor.