Investigations in chemical safety are necessary in case that the reaction course depends on changes of the reaction conditions sensitively. To break off a conversion in a hazardous situation, the precision calorimeter ACTRON 5 is equipped with two safety pumps. They empty and rinse the reactor with cold solvent. The pumps will be activated automatically. For testing the calorimeter the complex reaction of chloronitrobenzene with alkalined alcohol was used and break off at predefined conditions. The possibility of the kinetic estimation of these break-off files is shown.