Recommendations and guidelines for the safety evaluation of ammonium nitrate systems with the use of thermal analysis

Abstract

Ammonium nitrate (AN) is a critical material widely used in fertilizers, propellants, and other industrial applications. Despite its importance, AN has been linked to numerous catastrophic incidents worldwide, underscoring the urgent need for rigorous and standardized safety evaluations. Its thermal decomposition behavior is highly sensitive to conditions such as temperature, pressure, impurities, and system configuration. However, inconsistent methodologies in thermal analysis have led to variable results and unreliable safety assessments, limiting their value for risk prediction and regulatory compliance.

This study presents a comprehensive set of experimental guidelines for evaluating the thermal stability of AN-based systems. Original data are combined with extensive literature analysis to address key methodological variables including sample mass, gas flow conditions, heating programs, and crucible geometry. Particular attention is given to how these factors influence the transition from endothermic dissociation to exothermic runaway, which is essential for identifying worst-case decomposition behavior.

The proposed framework supports accurate simulation of decomposition pathways under conditions relevant to storage, transport, and industrial processing. By bridging gaps in methodology, this work provides practical, safety-oriented guidance that improves the reproducibility and relevance of thermal analysis data. The findings contribute directly to hazard identification, process safety evaluations, and the safe design and handling of reactive AN systems. This study serves as a valuable reference for engineers, researchers, and regulators seeking to enhance thermal hazard assessments and prevent accidental initiation in ammonium nitrate applications.