Decomposition of aromatic diazonium compounds

Abstract

The decomposition of diazonium salts caused an explosion in a peripheral part of a production plant. This incident was initiated by mechanical action and could not be associated with a definite diazonium compound. Therefore we have investigated the impact sensitivity of many of the diazonium chlorides which were produced in the plant. Aromatic diazonium salts were prepared in small portions of fractions of a gram in the laboratory and were subjected to drop-hammer tests and DTA experiments. The diazonium compounds derived from nitroanilines had a very low critical impact energy of 1-2J. With increasing molecular mass, the impact energy necessary for an explosion increased until an explosion was no longer observed. The results show that the hazards connected with diazonium salts can be classified by a drop-weight test. The discussion of the explosion incident shows that hazards must be expected in plants that produce diazonium salts although pure diazonium compounds are not involved in the actual process. Even small deposits in peripheral parts of the plant must be avoided. © 1993.