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Blood Agents


Blood agents are non-persistent agents that deprive the blood and organs of oxygen. They include arsine and cyanide.

  • Arsine (SA)
    A colorless, toxic gas that has mild garlic odor. This odor can only be detected at levels greater then those necessary to cause poisoning. This agent is formed when arsenic comes into contact with an acid. It is most commonly used in the semiconductor and metals refining industries.
  • Cyanide (AC, CK)
    A rapidly acting, potentially deadly chemical that can exist in many forms including a colorless gas, hydrogen cyanide and cyanogen chloride, or a crystal form, potassium cyanide and sodium cyanide. In gas form, cyanide may give off a bitter almond smell, but not always.


The most common way that people can be exposed to arsine liquid is by breathing in the gas. People can be exposed to cyanide by breathing in the agent after it has been released into the air, or ingesting it by drinking contaminated water or eating contaminated food.


People exposed to arsine may experience the following symptoms within two to 24 hours:

  • Weakness
  • Fatigue
  • Headache
  • Drowsiness
  • Confusion
  • Shortness of breath
  • Rapid breathing
  • Nausea, vomiting and/or abdominal pain
  • Red or dark urine; decreased urine output
  • Yellow skin and eyes (jaundice)
  • Muscle cramps
  • Fever, chills, thirst

Exposure to large doses of arsine may cause the following:

  • Loss of consciousness
  • Convulsions
  • Paralysis
  • Respiratory failure, possibly leading to death (25 percent fatality rate)

Long-term side effects of exposure to arsine include:

  • Kidney damage
  • Numbness and pain in the extremities
  • Memory loss or confusion

(Exposure to the arsine vapor can cause symptoms to develop within one to two minutes)

People exposed to cyanide may have the following symptoms within minutes:

  • Rapid breathing
  • Restlessness
  • Dizziness
  • Weakness
  • Headache
  • Nausea and vomiting
  • Rapid heart rate
  • Possible development of "cherry red" skin and lips

Exposure to large doses of cyanide may cause the following:

  • Pulmonary edema
  • Convulsions
  • Low blood pressure
  • Slow heart rate
  • Loss of consciousness
  • Lung injury
  • Respiratory failure leading to death (cessation of breathing in two to four minutes; death in four to eight minutes)

Long-term side effects of exposure to cyanide include:

  • Permanent heart and brain damage


There is no antidote for arsine. Treatment usually consists of receiving supportive medical care in a hospital setting. Blood transfusions and intravenous fluids may be needed. Some people may even require artificial kidneys (hemodialysis) for kidney failure.

Treatment for cyanide poisoning includes receiving supportive medical care and antidotes. The preferred antidotes for cyanide are immediate sodium nitrite or sodium thiosulfate compound.

For more extensive information about these agents, please visit Centers for Disease Control and Prevention or U.S. Department of Health and Human Services.

Page last updated: May 13, 2021