Cyanide: Exposure, Decontamination, Treatment

What Cyanide Is

  • Cyanide is released from natural substances in some foods and in certain plants, including the pits and seeds of some common fruits.
  • In manufacturing, cyanide is used to make paper, textiles, and plastics. It is present in the chemicals used to develop photographs. Cyanide salts are used in metallurgy for electroplating, metal cleaning, and removing gold from its ore. Cyanide gas is used to exterminate pests and vermin in ships and buildings.
  • Cyanide is a rapidly acting, potentially deadly chemical that interferes with the body’s ability to use oxygen.
  • Cyanide can be a colorless gas or liquid, such as hydrogen cyanide (HCN) or cyanogen chloride (CNCl).
  • Cyanide can also be a crystal (solid) form such as sodium cyanide (NaCN) or potassium cyanide (KCN).
  • Cyanide is also known by the military designations AC (for hydrogen cyanide) and CK (for cyanogen chloride).
  • Cyanide is sometimes described as having a “bitter almond” smell, but does not always give off an odor, and not everyone can detect this odor.

How People Can Be Exposed to Cyanide

  • After a release of cyanide into the air, people can be exposed through skin contact or eye contact, or inhaling (breathing in) the cyanide gas. Breathing in cyanide gas causes symptoms to appear the quickest but swallowing solid or liquid cyanide can be toxic also.
  • Following a release of cyanide into water, people can be exposed by touching or drinking water.
  • Solid cyanide released into water can also produce hydrogen cyanide gas (HCN or AC) resulting in possibly inhaling (breathing in) the gas.
  • Eating, drinking, or touching food or drink contaminated with cyanide can expose people to cyanide. Contamination of food or drink is more likely with solid forms.
  • Cyanide gas is most dangerous in enclosed places where gas will be trapped.
  • Cyanide gas can disperse quickly in open spaces depending on the weather, making it less harmful outdoors.
  • Hydrogen cyanide (HCN or AC) gas is lighter than air, so the gas will rise. Cyanogen Chloride (CNCl or CK) is heavier and will sink to low-lying areas and increase the risk of exposure there.

Food Contaminated with Cyanide

  • Food not contained in glass or metal (such as plastic, paper, or cloth containers) that may have come into contact with solid, liquid, or gaseous should be avoided.
  • If the food is in an undamaged sealed glass or metal container, it should not be affected by a cyanide release. Wash the outside of the container before using.
  • If the food smells, tastes, or looks unusual, avoid using the food.
  • Follow any directions by local authorities.

Signs and Symptoms of Cyanide Exposure

During or immediately after exposure to small doses of cyanide, the following signs and symptoms may develop:

  • Chest pain
  • Chest tightness
  • Confusion
  • Dizziness
  • Eye pain
  • Eye tearing
  • Excitement
  • Difficulty breathing
  • Headache
  • Nausea
  • Rapid or slow heart rate
  • Rapid or slow breathing
  • Restlessness
  • Shortness of breath and
  • Vomiting
  • Weakness
  • Wheezing

Symptoms from cyanide poisoning can progress very rapidly when exposed to a large amount of cyanide. Exposure to a large amount of cyanide by any route (breathing, absorbing through skin, eating, or drinking), may cause other health effects as well:

  • Coma
  • Death
  • High or low blood pressure
  • Loss of consciousness
  • Lung injury
  • Seizures

What to Do If Exposed to Cyanide

  1. Get away from the area where the cyanide was released and breathe fresh air. Make sure you understand your local emergency notification system if you have one. Refer to emergency broadcasts and local authorities for instructions.
  • If the cyanide release was outdoors, go indoors and shelter in place. Make sure windows are closed and ventilation systems are turned off to make sure the contamination does not come inside. If you cannot go indoors, leave the area where the cyanide was released.
  • If the cyanide release was indoors, get out of the building.
  1. Get it off your body right away!

Taking off all layers of clothing (including jewelry and accessories), blotting any liquid, and showering is the best method for removing cyanide from your body. Ideally, undress and shower immediately or as soon as you can, as described below. If you cannot take off all layers, take off as many clothes as you can.

  • Avoid pulling clothing over your head. If you must pull clothing over your head, close your eyes and mouth, and hold your breath so you don’t get cyanide in your eyes, nose, or mouth. Place items in a designated area, preferably in a plastic bag.
  • If you wear contact lenses, take them out and place them with your clothing. Do not put contact lenses back in.
  • If contaminated with solid cyanide, skip this step and wash your body as described in the next bullet. Otherwise, use separate, dry, clean cloths, or paper towels to blot each part of your body where you feel liquid, beginning with your head and hair, and then your face, hands, body, arms, legs, and feet. Blot your skin for 10 seconds, then rub for 10 seconds any places on your skin or in your hair where you can see or feel liquid. Continue blotting and rubbing, with clean, dry cloths or paper towels, dropping used things to the floor. Repeat the process several times if you continue to feel liquid on you. Use a separate clean cloth or paper towels for each part of your body, and for each time you repeat the process.
  • First wash your hair, face, and hands, and then wash the rest of your body. Wash from your head to your feet, including armpits and groin, with lukewarm water and mild soap (if available) for about 90 seconds. Use soapy water for a minute, followed by a 30 second plain water rinse. Try not to let the water run into your eyes, nose, or mouth. Do not scrub!
  • If your eyes are burning or you can’t see normally, flush your eyes for 10–15 minutes with lukewarm water. Do not use eye drops.
  • Dry your face, then tilt your head back and dry your hair, and then dry down your body. Use anything that will soak up water. Drop used things to the floor. Dress in any available clean clothes to prevent hypothermia. This is especially important if temperatures are cool.
  • If emergency response services are available, leave used items on the floor and report their location to emergency personnel. Move as far from the used items as possible. Otherwise, put on waterproof or heavy gloves that won’t let liquid seep through. Gather all used things from the floor, including your clothes, and put them in a plastic bag. Remove gloves and put them in the plastic bag. Close the plastic bag and place it in a second plastic bag. Close up the second bag also.
  • Do not put the bags in the regular trash! Place the bags in an area where other people are unlikely to disturb them and come in contact with cyanide. Inform local authorities of the location of the bags for pick up.
  1. Get help. Call 911. Go to the hospital if local officials say it is safe to leave your home. If you need more information, call the Poison Control Center at 1-800-222-1222.

Treatment for Cyanide Exposure

Cyanide poisoning is treated with specific antidotes and supportive medical care in a hospital setting or by trained emergency personnel. Antidotes for cyanide poisoning are most useful if given as soon as possible after exposure. The most important thing is for victims to seek medical treatment as soon as possible.

If someone has ingested cyanide, do NOT induce vomiting.

Long-term Health Effects

Survivors of significant cyanide exposure may develop heart, brain, and nerve damage.

For a comprehensive list of chemical agent information, see Chemicals A-Z.