Standard Operating Procedure for Sodium Azide


University of North Carolina at Chapel Hill Standard Operating Procedure for Sodium Azide

EHS SOP #: 005

Version No.: 1.0

Supercedes: N/A

Sodium Azide Formula



Describe proper handling and disposal procedures for Sodium Azide and Sodium Azide solutions.

Sodium Azide is a colorless, odorless, crystalline solid that is readily soluble in water. It is used as a preservative of samples and stock solutions in laboratories. Typically, it is used in strengths of 0.1 to 2.0%. Pure Sodium Azide and concentrated solutions of Sodium Azide are acutely toxic and can be reactive when heated near their decomposition temperature. Dilute solutions of Sodium Azide should not be poured down the drain because it can react with metals in plumbing systems to form explosive metal halides.

Sodium Azide is also used as an explosive trigger in automobile airbags.

Health Effects

Sodium Azide is extremely toxic. Ingestion of small amounts can be fatal, LD50 Oral – Rabbit – 10mg/kg. Skin contact may also be fatal, LD50 Dermal – rabbit – 20mg/kg. Inhalation may also be fatal, LC50 Inhalation – rat – 37mg/m3. Sodium Azide prevents oxygen from being used by the cells in the body, thus killing them.

Signs of Acute Exposure

Eyes: Redness, pain, irritation

Skin: Irritation, redness, blisters. May be fatal if absorbed through the skin.

Ingestion: Irritation of the digestive tract, abdominal pain, nausea, sweating, vomiting, and diarrhea. May cause low blood pressure, rapid heart rate, skin discoloration, and possible coma.

Inhalation: Severe irritation of the respiratory tract with sore throat, cough, clear drainage from the nose, blurred vision, dizziness, shortness of breath, respiratory failure leading to death.
(Note: Hydrazoic Acid, generated when sodium azide reacts with acid or water, in gaseous form is lighter than air.)

Signs of Chronic Exposure

Liver and kidney damage. Repeated exposure may cause spleen damage. Laboratory studies have shown mutagenic effects, development of tumors in animals, and blood effects. Survivors of Sodium Azide poisoning may exhibit brain and heart damage.

Regulatory Limits

National Institute for Occupational Safety and Health (NIOSH): Recommended exposure limit is 0.3 mg/m3 - ceiling (skin) - as Sodium Azide. 0.1 ppm as Hydrazoic Acid.

American Conference of Governmental Industrial Hygienists (ACGIH): Recommended threshold limit value - ceiling - of 0.3mg/m3 as Sodium Azide. 0.1 ppm as Hydrazoic Acid.


Based on the risk associated with the use of Sodium Azide, the safety procedures outlined below are required by all research staff when working with Sodium Azide.

Administrative Controls

  • Anyone who uses Sodium Azide is required to review this SOP and the attached Safety Data Sheet (SDS) prior to work.
  • Storage should take place in a secure, cool, ventilated area, with a tightly closed container.
  • Keep segregated away from acids and other incompatibles such as metals and oxidizing or reducing reagents.
  • Keep quantities to a minimum and only order what you will be using.
  • An eye wash should be available in the room with a safety shower accessible nearby.
  • If using large quantities or heating sodium azide in a chemical reaction, a blast shield should be in place.

Engineering Controls

  • Sodium Azide powder must be used in a functioning chemical fume hood including when weighing out powders or if being used in a chemical reaction.
  • Concentrating solutions on a rotary evaporator or drying under vacuum should also take place within a chemical fume hood.
  • Never use a metal spatula when manipulating Sodium Azide.

Personal Protective Equipment (PPE)

  • For sodium azide solutions: Nitrile gloves, a lab coat, and safety glasses.
  • If using large quantities or heating sodium azide in a chemical reaction, nitrile gloves (double gloving recommended), a lab coat, safety glasses and a face shield should be used during manipulations.

Waste Disposal

  • All Sodium Azide waste, including dilute solutions and contaminated solid waste (weigh paper, pipet tips, gloves, etc) will be disposed of as a hazardous material through EHS.
  • Do not discard Sodium Azide waste down the sink. Do not mix Sodium Azide waste with acidic waste.

Accidents or Injuries

If Sodium Azide is splashed on an individual or in eyes, flush for 15 minutes with copious quantities of water and immediately contact the University Employee Occupational Health Clinic (919-966-9119).

Spill Procedures

  • Do not attempt to clean-up if you feel unsure of your ability to do so or if you perceive the risk to be greater than normal laboratory operations.
  • If a small spill occurs rapidly absorb any liquid with absorbent pads or paper towels and place in a non-metallic container.
  • If a large spill occurs notify others in the area and evacuate room immediately. Contact EHS (919-962-5507) during working hours and 911 if after hours.

Contact Information

Policy Contact

Environment, Health & Safety
1120 Estes Drive
Campus Box #1650
Chapel Hill, NC 27599-1650
Phone: 919-962-5507

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Article ID: 132075
Thu 4/8/21 9:23 PM
Tue 10/18/22 10:51 AM
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03/01/2014 12:00 AM
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Environment, Health and Safety