Hydrazoic acid, safe handling

Concentrated solutions of hydrazoic acid are not safe to handle as they explode on mild mechanical shock and may also explode spontaneously. Dilute... 

The fact that most of these tetrazole side chain elements for Cephalosporins since years are now produced worldwide at a volume of several 100 t/a demonstrates that azide chemistry - whose evolution to commercial scale was originally a source for concern -has come of age. It is now also offered as a standard production process by manufacturers that have specialized on the safe handling of the risk potential, also in custom synthesis. The safety risks associated with the handling of azides should not be underestimated, however. Its toxicity and the latent hazard of formation of highly explosive hydrazoic acid intermediates require expertise and plants with specific safety features for the safe handling of azides. 

Figure 11 Safe handling of hydrazoic acid forthe synthesis of 5-substituted IH-tetrazoles in a microfluidic system.

In addition, sodium azide and hydrazoic acid must be handled safely. In working with sodium azide, the salt must not come in contact with copper, lead, mercury, silver, gold, their alloys, and their compounds. All of these form sensitive explosive azides. Azide salts must not be thrown into sinks or sewers since all azide salts are highly toxic, react with acids to form explosive, toxic, and gaseous hydrazoic acid, and react with copper and lead pipes. Azides and hydrazoic acid are thought to be more toxic than cyanides and hydrogen cyanide [7a]. 

The major portion of this volume is taken up by hydrogen azide or hydrazoic acid, HN3, the first member in the series of trinitrogen compounds. Known to be highly explosive in pure form, it can be safely handled when diluted. Thus, a great deal of information is available mainly on its properties as a chemical reagent and its decomposition processes. 

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