Sodium Azide: Systemic Agent

CAS #:
26628-22-8

RTECS #: VY8050000

UN #: 1687 (Guide 153)

Common Names:

  • Azide
  • Azium
  • Sodium salt of hydrazoic acid

Agent Characteristics

Colorless to white hexagonal crystalline solid.

Sodium azide exists as an odorless white solid. When mixed with water or an acid it changes rapidly to a toxic gas with a sharp odor as well as releasing hydrazoic acid (HN3). The odor of the gas may not provide sufficient warning of exposure. Persons who work on automobiles regularly are at an increased risk of exposure to sodium azide, which is used as a propellant in airbags. Sodium azide is also used in the preparation of various chemicals; in agriculture, as a preservative and as a microorganism fumigant; in clinical and research laboratories; in sponge rubber; in detonators; and as an intermediate in explosives manufacturing. Exposure to sodium azide can be fatal.

  • Indoor Air: Sodium azide can be released into indoor air as fine particles (aerosol).
  • Water: Sodium azide can be used to contaminate water.
  • Food: Sodium azide can be used to contaminate food.
  • Outdoor Air: Sodium azide can be released into outdoor air as fine particles (aerosol).
  • Agricultural: If sodium azide is released into the air as fine particles (aerosol), it has the potential to contaminate agricultural products.

Sodium azide can be absorbed into the body by inhalation, ingestion, skin contact, or eye contact. Ingestion is an important route of exposure to solid sodium azide. Inhalation is an important route of exposure to the vapor, hydrazoic acid.


Personal Protective Equipment

First Responders should use a NIOSH-certified Chemical, Biological, Radiological, Nuclear (CBRN) Self Contained Breathing Apparatus (SCBA) with a Level A protective suit when entering an area with an unknown contaminant or when entering an area where the concentration of the contaminant is unknown. Level A protection should be used until monitoring results confirm the contaminant and the concentration of the contaminant.
NOTE: Safe use of protective clothing and equipment requires specific skills developed through training and experience.

Select when the greatest level of skin, respiratory, and eye protection is required. This is the maximum protection for workers in danger of exposure to unknown chemical hazards or levels above the IDLH or greater than the AEGL-2.

  • A NIOSH-certified CBRN full-face-piece SCBA operated in a pressure-demand mode or a pressure-demand supplied air hose respirator with an auxiliary escape bottle.
  • A Totally-Encapsulating Chemical Protective (TECP) suit that provides protection against CBRN agents.
  • Chemical-resistant gloves (outer).
  • Chemical-resistant gloves (inner).
  • Chemical-resistant boots with a steel toe and shank.
  • Coveralls, long underwear, and a hard hat worn under the TECP suit are optional items.

Select when the highest level of respiratory protection is necessary but a lesser level of skin protection is required. This is the minimum protection for workers in danger of exposure to unknown chemical hazards or levels above the IDLH or greater than AEGL-2. It differs from Level A in that it incorporates a non-encapsulating, splash-protective, chemical-resistant splash suit that provides Level A protection against liquids but is not airtight.

  • A NIOSH-certified CBRN full-face-piece SCBA operated in a pressure-demand mode or a pressure-demand supplied air hose respirator with an auxiliary escape bottle.
  • A hooded chemical-resistant suit that provides protection against CBRN agents.
  • Chemical-resistant gloves (outer).
  • Chemical-resistant gloves (inner).
  • Chemical-resistant boots with a steel toe and shank.
  • Coveralls, long underwear, a hard hat worn under the chemical-resistant suit, and chemical-resistant disposable boot-covers worn over the chemical-resistant suit are optional items.

Select when the contaminant and concentration of the contaminant are known and the respiratory protection criteria factors for using Air Purifying Respirators (APR) or Powered Air Purifying Respirators (PAPR) are met. This level is appropriate when decontaminating patient/victims.

  • A NIOSH-certified CBRN tight-fitting APR with a canister-type gas mask or CBRN PAPR for air levels greater than AEGL-2.
  • A NIOSH-certified CBRN PAPR with a loose-fitting face-piece, hood, or helmet and a filter or a combination organic vapor, acid gas, and particulate cartridge/filter combination or a continuous flow respirator for air levels greater than AEGL-1.
  • A hooded chemical-resistant suit that provides protection against CBRN agents.
  • Chemical-resistant gloves (outer).
  • Chemical-resistant gloves (inner).
  • Chemical-resistant boots with a steel toe and shank.
  • Escape mask, face shield, coveralls, long underwear, a hard hat worn under the chemical-resistant suit, and chemical-resistant disposable boot-covers worn over the chemical-resistant suit are optional items.

Select when the contaminant and concentration of the contaminant are known and the concentration is below the appropriate occupational exposure limit or less than AEGL-1 for the stated duration times.

  • Limited to coveralls or other work clothes, boots, and gloves.

Emergency Response

  • Reacts explosively and/or forms explosive and/or shock sensitive compounds with acids and many metals.
  • Reacts vigorously with heated water.
  • Corrosive to aluminum and copper.
  • Contact with metals may evolve flammable hydrogen azide.
  • Contact with acid produces toxic hydrazoic acid vapors.
  • Sodium azide may explode when heated above its melting point, especially if heated rapidly.
  • It may decompose explosively with shock, concussion, or friction.
  • It reacts explosively with bromine, carbon disulfide, and chromyl chloride.
  • It forms explosive compounds with phosgene, brass, zinc, trifluoroacrylol fluoride, and nitrogen-diluted bromine vapor.
  • Reacts with copper, lead, silver, mercury, and carbon disulfide to form shock-sensitive compounds.
  • Reacts with acids to form explosive hydrazoic acid.
  • When heated, vapors may form explosive mixtures with air, presenting an explosion hazard indoors, outdoors, and in sewers.
  • Containers may explode when heated.
  • Sodium azide is combustible.
  • The agent may burn, but it does not ignite readily.
  • Fire may produce irritating, corrosive, and/or toxic gases.
  • The agent may be transported in a molten form.
  • For small fires, use dry chemical, carbon dioxide, or water spray.
  • For large fires, use dry chemical, carbon dioxide, alcohol-resistant foam, or water spray. Move containers from the fire area if it is possible to do so without risk to personnel. Dike fire control water for later disposal; do not scatter the material.
  • For fire involving tanks or car/trailer loads, fight the fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after the fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tanks. Always stay away from tanks engulfed in fire.
  • Run-off from fire control or dilution water may be corrosive and/or toxic, and it may cause pollution.
  • If the situation allows, control and properly dispose of run-off (effluent).
  • If a tank, rail car, or tank truck is involved in a fire, isolate it for 0.5 mi (800 m) in all directions; also consider initial evacuation for 0.5 mi (800 m) in all directions.
  • This agent is not included in the DOT ERG 2004 Table of Initial Isolation and Protective Action Distances.
  • In the DOT ERG 2004 orange-bordered section of the guidebook, there are public safety recommendations to isolate a sodium azide (Guide 153) spill or leak area immediately for at least 150 ft (50 m) for liquids and 75 ft (25 m) for solids in all directions.
  • Sodium azide will initially sink in water.
  • Sodium azide is decomposed by sunlight and irradiation.
  • Health: 3
  • Flammability: 0
  • Reactivity: 3
  • Special:

Health: 3, Flammability: 0, Reactivity: 3, Special:

  • OSHA: ID 211
  • NIOSH: Not established/determined
References are provided for the convenience of the reader and do not imply endorsement by NIOSH.
  • AIR MATRIX
    OSHA [1992]. Sodium azide and hydrazoic acid in workplace atmospheres: OSHA-SLTC Method ID-211. Salt Lake City, UT: U.S. Department of Labor, Occupational Safety and Health Administration.
  • OTHER
    No references were identified for this sampling matrix for this agent.
  • SOIL MATRIX
    No references were identified for this sampling matrix for this agent.
  • SURFACES
    No references were identified for this sampling matrix for this agent.
  • WATER
    No references were identified for this sampling matrix for this agent.

Signs/Symptoms

Clinical effects may be nearly immediate or delayed in onset following sodium azide exposure, and they may require days or months to fully resolve in some cases.

Sodium azide is a broad-spectrum, metabolic poison (toxin) that interferes with the body’s ability to use oxygen to support life. The most commonly reported health effect is low blood pressure (hypotension); this effect occurs following exposure by all routes: ingestion, skin contact, or inhalation. Ingestion and inhalation exposures may both cause headache, short-term loss of consciousness (syncope), loss of muscle tone and strength, long-term loss of consciousness (coma), and seizures. Following mild to moderate exposure, laboratory findings include elevated white blood cell count. With severe exposure, laboratory findings include build-up of acids in the blood stream due to interference with the body’s ability to use oxygen (lactic acidosis). In extreme cases sodium azide toxicity may be fatal.

  • Irritation and inflammation of the membranes (conjunctivitis), blurred vision, and dilated pupils (mydriasis).
  • Mild to moderate: Mild low blood pressure (hypotension), headache, general feeling of apprehension and being unwell, temporary loss of consciousness (syncope), nausea, vomiting (emesis), diarrhea, abdominal pain, and excessive thirst (polydipsia).
  • Severe: Severe low blood pressure (hypotension), sometimes preceded by high blood pressure (hypertension), reduced level of consciousness (CNS depression), seizures, coma, chest discomfort, slow or rapid heart rate (bradycardia or tachycardia), abnormal or disordered heart rhythms (atrial and ventricular dysrhythmias), difficulty breathing or shortness of breath (dyspnea), accumulation of fluid in the lungs (pulmonary edema), exceptionally high body temperature (hyperthermia) or lower than normal body temperature (hypothermia), profuse sweating (diaphoresis), and blurred vision. Seizures, coma, and death.
  • Inhalation exposure and ingestion exposure may cause similar adverse health effects (see Ingestion Exposure).
  • Gastrointestinal effects (nausea, vomiting, and diarrhea) may be less severe with inhalation exposure.
  • In addition, exposure to sodium azide vapors (hydrazoic acid) can cause:
  • Irritation of the eyes and the mucous membranes of the respiratory tract (nose and throat), possible inflammation of the airways (bronchitis), and fluid build up in the lungs (pulmonary edema).
  • Local effects: Irritation and inflammation. Possible blistering of skin.
  • Whole-body (systemic) effects: Low blood pressure (hypotension).
  • See ingestion for more comprehensive information.

Decontamination

The purpose of decontamination is to make an individual and/or their equipment safe by physically removing toxic substances quickly and effectively. Care should be taken during decontamination, because absorbed agent can be released from clothing and skin as a gas. Your Incident Commander will provide you with decontaminants specific for the agent released or the agent believed to have been released.

The following are recommendations to protect the first responders from the release area:

  • Position the decontamination corridor upwind and uphill of the hot zone. The warm zone should include two decontamination corridors. One decontamination corridor is used to enter the warm zone and the other for exiting the warm zone into the cold zone. The decontamination zone for exiting should be upwind and uphill from the zone used to enter.
  • Decontamination area workers should wear appropriate PPE. See the PPE section of this card for detailed information.
  • A solution of detergent and water (which should have a pH value of at least 8 but should not exceed a pH value of 10.5) should be available for use in decontamination procedures. Soft brushes should be available to remove contamination from the PPE. Labeled, durable 6-mil polyethylene bags should be available for disposal of contaminated PPE.

The following methods can be used to decontaminate an individual:

  • Decontamination of First Responder:
    • Begin washing PPE of the first responder using soap and water solution and a soft brush. Always move in a downward motion (from head to toe). Make sure to get into all areas, especially folds in the clothing. Wash and rinse (using cold or warm water) until the contaminant is thoroughly removed.
    • Remove PPE by rolling downward (from head to toe) and avoid pulling PPE off over the head. Remove the SCBA after other PPE has been removed.
    • Place all PPE in labeled durable 6-mil polyethylene bags.
  • Decontamination of Patient/Victim:
    • Remove the patient/victim from the contaminated area and into the decontamination corridor.
    • Remove all clothing (at least down to their undergarments) and place the clothing in a labeled durable 6-mil polyethylene bag.
    • Thoroughly wash and rinse (using cold or warm water) the contaminated skin of the patient/victim using a soap and water solution. Be careful not to break the patient/victim’s skin during the decontamination process, and cover all open wounds.
    • Cover the patient/victim to prevent shock and loss of body heat.
    • Move the patient/victim to an area where emergency medical treatment can be provided.

First Aid

Initial treatment is primarily supportive. Patient/victims exposed to sodium azide frequently do not respond to classical fluid resuscitation and vasopressors.

There is no antidote for sodium azide toxicity.

  • Immediately remove the patient/victim from the source of exposure.
  • Immediately wash eyes with large amounts of tepid water for at least 15 minutes.
  • Seek medical attention immediately.
  • Immediately remove the patient/victim from the source of exposure.
  • Ensure that the patient/victim has an unobstructed airway.
  • Do not induce vomiting (emesis).
  • Monitor heart function, and evaluate for low blood pressure (hypotension), abnormal heart rhythms (dysrhythmias), and reduced respiratory function (respiratory depression).
  • Evaluate for low blood sugar (hypoglycemia), electrolyte disturbances, and low oxygen levels (hypoxia).
  • Begin intravenous (IV) fluid administration; adjust the rate of fluid administration as necessary in order to maintain blood pressure.
  • Vomitus from patient/victims exposed to sodium azide can pose a risk of exposure to toxic hydrazoic acid gas. If the patient/victim vomits, clean up and isolate vomited material using paper towels and plastic bags.
  • Seek medical attention immediately.
  • Immediately remove the patient/victim from the source of exposure.
  • Evaluate respiratory function and pulse.
  • Ensure that the patient/victim has an unobstructed airway.
  • If shortness of breath occurs or breathing is difficult (dyspnea), administer oxygen.
  • Assist ventilation as required. Always use a barrier or bag-valve-mask device.
  • If breathing has ceased (apnea), provide artificial respiration.
  • Seek medical attention immediately.
  • Immediately remove the patient/victim from the source of exposure.
  • See the Decontamination section for patient/victim decontamination procedures.
  • Seek medical attention immediately.

Long-Term Implications

The patient/victim should be monitored for accumulation of fluid in the lungs (pulmonary edema), shock, and seizures, and treated as necessary. Drug therapy for treatment of pulmonary edema may be considered. Intubation is recommended for airway control in patient/victims who are unconscious, who have severe pulmonary edema, or who are in respiratory arrest; early intubation at the first signs of upper airway obstruction may be required. Patient/victims being treated with fluids for shock should be monitored for signs of fluid overload, especially if they have pulmonary edema. For hypotension and shock due to hypovolemia, carefully administer fluids. For hypotension and shock due to vasodilation, the use of vasopressors may be considered.

Patient/victims may take months to fully recover from exposure.

Sodium azide is not classifiable as a human carcinogen. It is unknown whether chronic or repeated exposure to sodium azide increases the risk of reproductive toxicity or developmental toxicity. Studies report that loss of the sheath around the nerves (demyelination) can occur with chronic large doses.


On-Site Fatalities

  • Consult with the Incident Commander regarding the agent dispersed, dissemination method, level of PPE required, location, geographic complications (if any), and the approximate number of remains.
  • Coordinate responsibilities and prepare to enter the scene as part of the evaluation team along with the FBI HazMat Technician, local law enforcement evidence technician, and other relevant personnel.
  • Begin tracking remains using waterproof tags.
  • Wear PPE until all remains are deemed free of contamination.
  • Establish a preliminary (holding) morgue.
  • Gather evidence, and place it in a clearly labeled impervious container. Hand any evidence over to the FBI.
  • Remove and tag personal effects.
  • Perform a thorough external evaluation and a preliminary identification check.
  • See the Decontamination section for decontamination procedures.
  • Decontaminate remains before they are removed from the incident site.
See Guidelines for Mass Fatality Management During Terrorist Incidents Involving Chemical Agents, U.S. Army Soldier and Biological Chemical Command (SBCCOM), November, 2001 for detailed recommendations.

Occupational Exposure Limits

  • NIOSH REL:
    • Ceiling: 0.1 ppm (as HN3) (skin)
    • Ceiling: 0.3 mg/m3 (as NaN3) (skin)
  • OSHA PEL:
    • Not established/determined
  • ACGIH TLV:
    • Ceiling: 0.29 mg/m3 (as NaN3)
    • Ceiling: 0.11 ppm (as HN3 vapor)
  • NIOSH IDLH: Not established/determined
  • DOE TEEL:
    • TEEL-0: 0.29 mg/m3
    • TEEL-1: 0.29 mg/m3
    • TEEL-2: 0.29 mg/m3
    • TEEL-3: 12.5 mg/m3
  • AIHA ERPG:
    • ERPG-1: Not established/determined
    • ERPG-2: Not established/determined
    • ERPG-3: Not established/determined

Acute Exposure Guidelines

Acute Exposure Guidelines
5 min 10 min 30 min 1 hr 4 hr 8 hr
AEGL 1
(discomfort, non-disabling) – mg/m3
Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined
AEGL 2
(irreversible or other serious, long-lasting effects or impaired ability to escape) – mg/m3
Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined
AEGL 3
(life-threatening effects or death) – mg/m3
Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined Not established/ determined

Decontamination (Environment and Equipment)

The following methods can be used to decontaminate the environment/spillage disposal:

  • Do not touch or walk through the spilled agent if at all possible. However, if you must, personnel should wear the appropriate PPE during environmental decontamination. See the PPE section of this card for detailed information.
  • Keep combustibles (e.g., wood, paper, and oil) away from the spilled agent. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact the spilled agent.
  • Do not direct water at the spill or the source of the leak.
  • Stop the leak if it is possible to do so without risk to personnel, and turn leaking containers so that gas rather than liquid escapes.
  • Prevent entry into waterways, sewers, basements, or confined areas.
  • Isolate the area until gas has dispersed.
  • Ventilate the area.

Agents can seep into the crevices of equipment making it dangerous to handle. The following methods can be used to decontaminate equipment:

  • Not established/determined

Agent Properties

  • Chemical Formula:
    NaN3
  • Aqueous solubility:
    Soluble
  • Boiling Point:
    Decomposes
  • Density:
    Solid: 1.846 g/cm3 at 68°F (20°C)
  • Flammability:
    Combustible
  • Flashpoint:
    Not established/determined
  • Ionization potential:
    11.70 eV
  • Log Kbenzene-water:
    Not established/determined
  • Log Kow (estimated):
    0.16
  • Melting Point:
    527°F (275°C) (decomposes)
  • Molecular Mass:
    65.01
  • Soluble In:
    Sodium azide is soluble in liquid ammonia, slightly soluble in alcohol, and insoluble in ether.
  • Specific Gravity:
    1.85
  • Vapor Pressure:
    Not established/determined
  • Volatility:
    Not established/determined

Hazardous Materials Warning Labels/Placards

  • Shipping Name:
    Sodium azide
  • Identification Number:
    1687 (Guide 153)
  • Hazardous Class or Division:
    6.1
  • Subsidiary Hazardous Class or Division:
  • Label:
    Poison (Toxic)
  • Placard Image:
    dot_class6_poison dot_class6_toxic

Trade Names and Other Synonyms

  • AI3-50436
  • Azide, sodium
  • Azoture de sodium (French)
  • Azydek sodu (Polish)
  • Kazoe
  • Natriumazid (German)
  • Natriummazide (Dutch)
  • NCI-C06462
  • Nemazyd
  • NSC 3072
  • Smite
  • Sodium salt of hydrazoic acid
  • Sodium, azoture de (French)
  • Sodium, azoturo di (Italian)
  • U-3886
Who to Contact in an Emergency

In the event of a poison emergency, call the poison center immediately at 1-800-222-1222. If the person who is poisoned cannot wake up, has a hard time breathing, or has convulsions, call 911 emergency services.

For information on who to contact in an emergency, see the CDC website at emergency.cdc.gov or call the CDC public response hotline at (888) 246-2675 (English), (888) 246-2857 (Español), or (866) 874-2646 (TTY).

Important Notice

The user should verify compliance of the cards with the relevant STATE or TERRITORY legislation before use. NIOSH, CDC 2003.