As Tilak points out, the use in the pH 6-8 (or higher) range is routine and not an issue, particularly at the low concentration.  However, the pKa for HN3 is 4.76, so low pH work will release HN3 gas.  I know, - I had it happen to me during my post-doc!. 

Azides can be handled safely, you just need to understand the reactivity.

Hello everyone,

I have a question from a faculty member and I need some help with my assessment on whether this is safe to do.

“I have an experiment where I used sodium azide at very low concentrations (0.01 mM/0.000065%, to inhibit an enzyme) and I'm wondering if this is okay to go in the HPLC (the eluent is 0.25% phosphoric acid). I only inject 15 uL of my sample into the HPLC per run, but I know interactions with acid can create toxic gases, so I just wanted to check about the best way to measure these samples and what safety precautions would be recommended for these concentrations.”

In looking at the SDS there are statements such as “reacts violently with acids” and “incompatible with metals and solvents”.

With the concentration this low, will this cause a problem? If so, is there an alternative?

Thanks, Ellen

Ellen Sweet

Laboratory Ventilation Specialist

Department of Environmental Health and Safety, Cornell University

American Chemical Society, Division of Chemical Health and Safety

315-730-8896

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