Sodium Azide

Videlock Laboratory · lab-specific standard operating procedure

This is a laboratory-written SOP, not a UCLA EH&S template. It is pending review with EH&S (laboratorysafety@ehs.ucla.edu) before being filed in the Chemical Hygiene Plan. The signed copy of record, with the PI approval and training signatures, is in the lab safety manual.

This SOP covers sodium azide and any reagent preserved with it. Sodium azide is banded by UCLA under the Acute Toxicants SOP, which covers the toxicity but not the explosive-metal-azide and hydrazoic-acid hazards that make azide unusual. Read this document together with the UCLA Acute Toxicants SOP. Use is subject to pre-approval by the PI.

Materials covered

Hazard description

Sodium azide inhibits cytochrome c oxidase, the same target as cyanide, and produces a comparable clinical picture: headache, hypotension, collapse. It is fatal in oral, dermal and inhalation exposure (acute toxicity category 1–2). There is no specific antidote; treatment is supportive only.

Azide reacts with copper, lead, brass and silver to form heavy-metal azides, which are shock-sensitive primary explosives. Azide poured down a drain accumulates in the metal trap and plumbing, where it can detonate years later when the pipe is disturbed. Drain disposal of azide is prohibited at UCLA with no exception for dilute solutions.

Acid contact liberates hydrazoic acid (HN₃) — volatile, explosive and acutely toxic. Contact with bleach or other hypochlorite forms chlorine azide, which is explosive. Never acidify or bleach azide-containing waste.

The dilute azide in antibody stocks is not an acute poisoning risk at the volumes used here, but it carries the full metal-azide and drain-disposal restriction.

Personal protective equipment

Lab coat Gloves Eye protection
Traditional white lab coat, buttoned, sleeves down. Nitrile gloves, double-gloved when handling the solid. Change immediately on any suspected contact. ANSI Z87.1-compliant safety glasses; goggles plus a face shield when handling the solid or volumes over 100 mL.

Engineering controls, equipment and work practices

   
Weighing solid azide Weigh only in a fume hood, using a dedicated spatula. Never weigh sodium azide on an open bench balance.
Solutions Prepare and handle solutions in a fume hood. Label every container with the full chemical name — not “NaN₃” — plus the concentration and the words “TOXIC — NO DRAIN DISPOSAL”.
Metal contact Keep azide away from metal spatulas, metal sinks and metal-bodied waste containers. Use plastic or glass throughout.
Working alone Do not handle solid sodium azide when working alone in the laboratory.

Labeling and storage

Store the solid in a tightly closed plastic or glass container inside a labelled secondary container, in a cool dry cabinet away from acids, oxidizers, bleach and all metal salts. Keep the container off metal shelving. Azide-preserved antibody stocks may be stored normally at 4 °C but must carry the no-drain-disposal label.

Housekeeping

Spills. Solid spill: do not sweep dry. Dampen with water, wipe up from the edge inward with disposable towels, and bag as hazardous waste. Solution spill: absorb with pads, then wipe with water only — never with bleach or with an acidic cleaner. Notify the PI and EH&S at (310) 825-9797 for any spill of solid azide, however small. For a large spill, evacuate and call 9-1-1 from a campus phone or (310) 825-1491 from a cell phone.

Decontamination. Wipe contaminated surfaces with detergent and water unless specified otherwise above. Dispose of contaminated towels as solid hazardous waste.

Waste

ALL azide-containing waste — including dilute antibody buffers, wash buffers and used staining solutions — goes into a labelled aqueous hazardous waste container. Never down the drain, at any dilution. Never into a waste stream that contains acid or bleach. Segregate azide waste from halogenated solvent waste and from any acidified waste.

Refer to the UCLA Chemical Hygiene Plan for general waste accumulation requirements.

First aid and emergencies

   
Any suspected exposure Treat as a medical emergency. Call 9-1-1 from a campus phone or (310) 825-1491 from a cell phone. Tell responders the exposure was to sodium azide and that its mechanism is similar to cyanide — this changes their management. Notify EH&S at (310) 825-9797.
Skin contact Remove contaminated clothing immediately; flush the skin with water for at least 15 minutes. Azide is absorbed through intact skin.
Inhalation Move to fresh air at once. Seek emergency medical attention even if the person feels well — hypotension can be delayed.
Eye contact Flush at an eyewash for 15 minutes and seek emergency medical attention.
Rescuer safety Do not perform mouth-to-mouth resuscitation on someone who may have ingested azide.

Emergency: 9-1-1 from a campus phone, or (310) 825-1491 from a cell phone · UCLA EH&S: (310) 825-9797

Training

Everyone who works with these materials reads this SOP and signs the training record held in the lab safety manual.

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