Revision - Original 4/2018

The requirements in Penn's Chemical Hygiene Plan SOP:  Acutely Toxic Chemicals apply to all work involving sodium azide.  The Fact Sheet below gives hazard information and precautions for working with this chemical; however, this information is provided as a supplement to the SOP, which must first be read and understood by anyone planning to work with this chemical.

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Sodium azide (NaN3, CAS: 26628-22-8) is used in dilute solutions as a preservative of biological samples and stock solutions.  Typical concentrations for use as a preservative are from 0.02 % to 0.1 %.  Sodium azide is also used in laboratories as a reagent in synthesis work.

Hazard Description

Hazard Description

Health Hazards

GHS Symbol for Health Hazard Outline of Person's Torso with Starburst on Chest
          Health Hazard
GHS Pictogram for Toxic Chemical Red Bordered Diamond with Skull and Cross Bones









Solid sodium azide is considered a “highly toxic chemical” as it is GHS Acute Toxicity category 1 for acute dermal toxicity and category 2 for acute oral toxicity.  Sodium azide is also category 2 for specific target organ toxicity (brain) from repeated oral exposure.

Routes of Exposure

Sodium azide can be absorbed through skin, by ingestion, or inhalation

Symptoms of Exposure

Ingestion or inhalation of sodium azide may cause dizziness, weakness, blurred vision, dyspnea (shortness of breath), hypotension (low blood pressure), slowed heart rate, and abdominal pain. Spasms, convulsions, and loss of consciousness may also occur.

Dermal or eye exposure to sodium azide may result in pain and redness of exposed areas. Eye exposure may also lead to blurred vision. 

Physical Hazards

Sodium azide is explosive when heated or on contact with lead, copper, zinc, cadmium, or nickel.  When mixed with acid, or on contact with these metals, sodium azide releases toxic gas (hydrazoic acid).

Purchase Recommendations

Purchase Recommendations

Whenever possible, sodium azide should be purchased as a pre-mixed stock solution of less than 5%. The diluted solution is less hazardous than the solid or more concentrated solutions.

Less Hazardous Alternatives

Use less toxic preservative when possible.  The product below is a popular alternative to sodium azide.

ProClin Preservatives:

Safe Handling, Use, and Disposal

Safe Handling, Use, and Disposal

The Chemical Hygiene Plan SOP for Acutely Toxic Chemicals contains general guidance for safe handling and proper disposal of highly toxic materials.  You must read and understand this SOP before working with sodium azide.

Special Considerations for this chemical

  • Reaction mixtures containing sodium azide should not be concentrated by rotary evaporation.  If rotary evaporation cannot be avoided, a Hazard Control Plan must be in place to describe how the risks will be minimized. Contact EHRS for assistance with your HCP.
  • Never use metal spatulas for weighing and transferring azides. Never scratch solid azides.