Cyanide compounds that can easily release the cyanide anion (CN¯) or are easily metabolized to release it in the body are considered highly toxic and particularly hazardous. Commonly encountered cyanide compounds at Stanford include salts such as potassium cyanide and sodium cyanide; these compounds typically come in the form of white granular or crystalline solids, but may also be dissolved in a solution. Other cyanide compounds used at Stanford may be liquids, such as trimethylsilyl cyanide.

What are the hazards?

Cyanide compounds can be inhaled as a powder or volatile liquid, absorbed through the skin, or accidentally injected or ingested. Cyanide compounds can react with water or acids to produce highly toxic hydrogen cyanide gas, an inhalation hazard.

Cyanide can kill within minutes to hours, with latency dependent upon the form, concentration, and route of exposure. Some cyanide compounds (and hydrogen cyanide gas) have a faint, bitter almond-like odor. However, the odor does not provide adequate warning of hazardous concentrations, and a large proportion of individuals cannot detect it due to a genetic trait.

SYMPTOMS OF CYANIDE EXPOSURE

The symptoms of cyanide exposure vary depending upon the degree and route of the exposure. Early symptoms of cyanide exposure may include some or all of the following: headache, lightheadedness, dizziness, nausea, vomiting, agitation, drowsiness, and irritation of the eyes, nose, throat and respiratory tract, as well as rapid breathing with a sense of suffocation.

Severe cyanide exposure symptoms are convulsions, stupor, paralysis, unconsciousness, and coma. Death may occur within minutes.

How can I protect myself?

Planning the experiment

• If possible, eliminate cyanide compound use or replace with a less toxic chemical.
• Consult with your principal investigator (PI) prior to using cyanides.
• Consult the Safety Data Sheet (SDS) for the hazards associated with the specific cyanide compound you are using. Keep a copy in your lab at all times.
• Develop a standard operating procedure (SOP) for your experiment that describes in detail how to perform the experiment safely and effectively. Read more about SOP development.

Minimize the amount of cyanide compounds used during experiments. Contact EH&S at (650) 723-0448 if you are considering using hydrogen cyanide gas.

Safe Handling

• Establish a designated area for working with cyanide compounds. Clearly mark with signs identifying the chemical hazard and include an appropriate warning.
• Handle cyanide compounds (including weighing and/or transferring between storage containers) in a certified laboratory chemical fume hood.
• Keep acids out of the fume hood unless needed for the experiment. If needed, keep the quantity to a minimum.
• Be aware that many cyanide compounds will react with acids to form hydrogen cyanide gas.
• Ensure the nearest emergency safety shower/eyewash is accessible and has been tested within the last month.
• Do NOT work alone when using cyanide compounds; limit work to normal working hours (8:00 AM – 5:00 PM).

​Personal Protective Equipment

Minimum Personal Protective Equipment (PPE) must be worn when working with cyanide compounds and includes the following:

• Lab coat
• Chemical-resistant gloves (double gloving recommended)
• Safety glasses (use safety goggles and a face shield where a potential splash or dust hazard exists)

Proper street clothing: long pants and closed toe shoes

Decontamination

• To clean fume hood surfaces, utensils, and glassware contaminated with cyanide compounds, first use a pH 10 buffer solution, followed by cleaning with a freshly prepared 10% bleach solution.
• Conduct cleaning activities within the fume hood only.

Training

Lab-specific training for cyanide users must include:

• Instructions for safe usage
• Signs and symptoms of cyanide exposure
• Emergency response procedures
• Review of lab specific SOP

Emergency procedures

SPILL RESPONSE

• For spills of cyanide compounds inside a fume hood, ensure all contaminated surfaces are cleaned first with pH 10 buffer solution followed by cleaning with a freshly prepared 10% bleach solution. The contaminated solution/wipes must be disposed of as cyanide-containing hazardous waste. Contact EH&S if large quantities are spilled or if the researcher is unsure on how to proceed (650-725-9999).
• For spills of cyanide compounds or release of hydrogen cyanide gas outside of a fume hood (such as from spills of sodium cyanide solutions) follow the procedures below:
  1. Evacuate the area and any affected personnel.
  2. Alert emergency personnel by calling 911 from a cell phone
  3. For any affected personnel, follow procedures in “Onsite Exposure Response Instructions” section on the following page
  4. Alert people in the vicinity and/or activate local alarm systems.
  5. Remain nearby to advise emergency personnel.
  6. Once personal safety is established, call EH&S at 725-9999

ONSITE EXPOSURE RESPONSE instruction

For an ACTUAL or SUSPECTED exposure to cyanide, do NOT wait for symptoms to develop to contact emergency services.

For actual or suspected exposures to cyanide, follow the steps below:

1. Call 911; inform them that a cyanide exposure has taken place
2. Ensure onsite responders wear PPE (including lab coat, double nitrile gloves, and eye protection) to prevent potential skin and eye contact with cyanide compounds.
3. Remove the affected individual(s) from the environment containing cyanide.
4. Remove all contaminated clothing.
5. For skin and hair contact, thoroughly rinse affected areas in a safety shower with water for 15 minutes.
6. For eye contact, flush using the emergency eye wash or saline water for 15 minutes.

Do NOT delay transport if the affected individual is unconscious.

Do NOT perform mouth-to-mouth/mouth-to-nose CPR for unconscious individuals with inhalation exposure, to prevent the rescuer from becoming exposed. If trained in the proper procedures, perform chest compressions only.

Bring a copy of the SDS for the cyanide compound with the affected individual(s) to the Stanford Hospital Emergency Room.

Please note that while many researchers learned that isoamyl nitrite is an antidote to cyanide exposure, it is no longer approved for such use. The only FDA-approved antidotes must be administered by IV by a qualified medical professional, therefore storage and use of cyanide antidotes in the lab is no longer acceptable.

Contact the Stanford Occupational Health Center (OHC) if there are any questions regarding symptoms of cyanide exposure. (Hours: Monday – Friday, 8:00 AM – 5:00 PM, Phone: 650-725-5308, After Hours: 650-725-9999)

How do I store this?

Store cyanide compounds in a cool, dry, and well-ventilated area, out of direct sunlight and heat. They must also be stored according to the correct storage group.

How do I DISPOSE OF this?

• If your lab has cyanide compounds that are no longer in use, dispose of them as surplus chemicals or hazardous waste.
• Manage cyanide-containing wastes as hazardous waste
• Store cyanide wastes in dedicated waste containers used only to store cyanide waste.
• Solid (all contaminated gloves, matting, paper towels, etc.) and liquid cyanide wastes must be stored separately.
• EH&S provides waste containers for solid waste; contact your Safety & Compliance Advisor for more information.
• Create hazardous waste tags and request pick up. Attach completed tags to containers.