Chemical Safety: Sodium Azide Hazards

Robert Seibert's letter contains an interesting account of an explosion that involved sodium azide (NaN₃) in the late 1940s (C&EN, Nov. 9, 2009, page 8). Following the dreadful accident, Seibert remembers remarking that the explosion must have been caused by wet methanol and warns about the dangers of adding sodium azide to wet methanol.

Because no further details about the contents of the reactor are given, there is nothing I can say about it but to clarify that NaN₃ does not form explosive compounds when dissolved in water. Besides its toxicity, the danger associated with NaN₃ is its ability to form explosive azides when reacted with heavy metals such as lead, copper, zinc, cadmium, or nickel.

Cesar Aliaga
Albany, Calif.