Revisiting Thermal Safety

Although the current trend in Fine and Specialty Chemistry is to gradually replace traditional semi-batch processes with Flow Chemistry processes, which are safer, cleaner, and faster, most production continues to be semi-batch. This paper is devoted to recovering the basic concepts of thermal safety of such semi-batch processes. Experimental techniques such as reaction calorimetry, differential scanning calorimetry and accelerating rate calorimetry are the key to safety studies. The data obtained allow the criticity of a process to be classified into the five Stoessel's classes, from less to most dangerous. The safety improvement strategy of a reaction process always consists of trying to lower its criticality class.