Sodium Azide Precautions

Two recent articles refer to the hazards of working with sodium azide (NaN₃) (C&EN, Jan. 11, page 4, and Nov. 9, 2009, page 8). American Azide Corp., a division of American Pacific Corp. (AMPAC), has safely produced more than 9 million kg of sodium azide over the past 17 years. The azide ion is an extremely useful nucleophile that has been used safely for many years at companies such as AMPAC Fine Chemicals (AFC, formerly Aerojet Fine Chemicals). AFC has used this reagent on a commercial scale for more than 50 years in the production of intermediates for the pharmaceutical and defense industries. Sodium azide is the reagent of choice for the production of primary amines, isocyanates, and several heterocyclic compounds and is widely used in the synthesis of a number of pharmaceuticals, including Avapro, Diovan, and Tamiflu.

As with many chemicals deemed hazardous, sodium azide can be safely handled and used in large-scale chemical processes as long as certain precautions are taken (see, for example, Chemical Market Reporter, Jan. 3, 2005, page 267). Incompatibility of sodium azide with certain heavy metals is well-known. However, the reactivity of NaN₃ with acids to form hydrazoic acid is not well publicized.

The formation of hydrazoic acid, and in particular condensation of neat hydrazoic acid, must be avoided under all possible conditions. As chemists and engineers, we should understand the true hazards of the chemical involved and then put controls in place to handle it safely. Finally, we should be vigilant in our education of chemists regarding the safe handling of these compounds, whether in university, industrial, or government laboratories.

Kent Richman
Vice President, Research & Product Development, American Pacific Corp.
Las Vegas