Health Library

Botulinum Toxin—Biological Weapon


Botulinum toxin is the most poisonous substance known to man. Even a small amount is lethal. It is produced by a certain bacteria. A number of countries that support terrorism are developing or have the toxin as a germ-warfare weapon. As a weapon, the toxin might be released in the air or placed in the food supply. The toxin causes the disease botulism.

In tiny doses, the toxin is injected as a treatment for medical conditions, such as eyelid muscle spasms and migraine headaches.


Botulinum toxin poses a great threat. It is easy to produce and transport. Only 1 gram of the toxin evenly released and inhaled could kill 1 million people. However, it is hard to keep stable for release in the air.

Some experts believe it would not work in stopping a military enemy. US troops receive a botulinum toxoid vaccine to prevent the disease if exposed to the toxin. However, release of the toxin in a civilian population would present serious results.

Botulinum toxin is colorless and odorless. The toxin cannot be passed from one person to another.

Inhaled Toxin Pathway in Body
Spores in lungs
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Risk Factors

Factors that increase your risk of botulism include:

  • Exposure to the toxin after its release during a biological terrorism attack
  • Rarely, accidental exposure to the toxin may occur as a result of food contamination, especially if the contaminated food was not packaged or heated properly


Experts predict symptoms from an airborne bioterrorism attack would begin 12-72 hours after exposure. Symptoms from a food attack could start within 2 hours or as long as 8 days after eating food with the toxin. Severity and speed of onset might vary depending on the amount of toxin absorbed.

Symptoms include:

  • Double or blurred vision
  • Trouble swallowing
  • Difficulty speaking
  • Weakness in clenching jaw
  • Droopy eyelids
  • Loss of head control
  • Weakness, on both sides, starting at the head and working down the body
  • Constipation
  • Inability to move limbs


You will be asked about your symptoms and medical history. A physical exam will be done. You may also be asked about a possible source of exposure. Expect to answer questions about where you have been and what you have eaten. Samples of questionable food may be tested. Other cases in the area may alert healthcare workers to the possibility of a bioterrorism attack. Special tests to confirm a diagnosis take days to complete.

Your bodily fluids, tissues, and waste will be tested. This can be done with:

Images may be taken of your bodily structures. This can be done with an MRI scan..

Your nerves may be tested. This can be done with electromyogram and nerve conduction tests.


Early therapy with an antitoxin is essential to decrease resulting nerve damage. Treatment should start before test results are available.


If started early, an antitoxin can stop the paralysis from progressing and may shorten symptoms. It does not reverse the disease process.

Supportive Care

The most serious complication is respiratory failure. Treatment aims to maintain adequate oxygen supply. Patients may require a ventilator and close monitoring in an intensive care unit. Feeding through a tube also may be needed. Recovery occurs after the body produces new nerve fibers. This process may take weeks or months.

Public Health Measures

Cases are reported to public health officials. Contaminated clothing and surfaces should be washed with a bleach solution or left untouched for days.

Methods to Eliminate the Toxin

Methods to eliminate the toxin include:

  • Enemas
  • Suctioning of stomach contents


Antitoxin could be given after a known release of the toxin. However, there are limited supplies of antitoxin. In the event of a terrorism attack, the antitoxin likely would be given to patients at the first signs of illness.

Laboratory workers and military personnel can receive a toxoid vaccine to prevent the disease by building immunity.

There would be no warning systems to alert authorities that the toxin has been released. The success of an attack would depend on its secrecy, the size of the toxin particle, and weather conditions at the time of release. If aware of an attack, covering your mouth and nose with clothing or a towel might offer some protection. Experts predict some of the released toxin could live in dry, cool air for up to 2 days.

Botulinum toxin in food or drink can be inactivated by heating to 85 degrees Celsius (185 degrees Fahrenheit) for at least 5 minutes.

Botulinum toxin is also degraded under general environmental conditions. Exposed objects can be decontaminated by washing them with bleach.


Centers for Disease Control and Prevention

US Department of Health and Human Services: Food Safety

Canadian Resources

Ontario Ministry of Health and Long-term Care

Public Health Agency of Canada


Botulism. Centers for Disease Control and Prevention website. Available at: Updated April 25, 2014. Accessed May 27, 2015.

Consensus statement: botulinum toxin as a biological weapon: medical and public health management. JAMA. 2001;285(8).