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Botulism (Food-borne)

What is food-borne botulism?

The bacterium Clostridium botulinum, which is found throughout the environment (i.e. soil and water) produces a toxin which is the cause of food-borne botulism. Botulism is an illness that can result in paralysis of the central nervous system, leading to organ failure and even death. Food or drink that contains the botulism toxin can cause food-borne botulism. Although rare, food-borne botulism is a serious health threat requiring medical attention.


The following foods have been found to be connected to cases of food-borne botulism:

  • Improperly canned or preserved low-acid foods (i.e. corn, peas, tomatoes, fish)
  • Improperly handled and stored foods kept in oils (i.e. vegetables, herbs, spices)
  • Improperly stored low-acid juices (i.e. carrot juice)
  • Improperly handled and stored baked potatoes wrapped in aluminum foil
  • Honey (pasteurized or unpasteurized) is a concern to infants under the age of one year as it has been linked to infant botulism. Honey cannot support the growth of Clostridium botulinum, but once ingested by a baby, the bacterium can produce the toxin causing illness.

Food-borne botulism cannot be spread from person-to-person.


  • Muscle weakness
  • Vision problems
  • Dry mouth
  • Difficulty speaking
  • Nausea or vomiting, sometimes accompanied by diarrhea
  • Trouble breathing/Respiratory failure
  • Heart failure/Cardiac failure
  • Paralysis starting from the top of the body, moving downwards
  • Death Symptoms can begin anywhere from 6 hours after eating food containing the botulism toxin to 10 days afterwards. Usually the onset of symptoms occurs with 12 to 36 hours.

Food-borne botulism symptoms can be long term, lasting for weeks or months.



Food-borne botulism is diagnosed by either a brain scan or spinal fluid testing. Blood and stool tests can confirm the diagnosis. Food-borne botulism is treated with a botulism antitoxin. The antitoxin can help prevent complications such as respiratory failure. Without timely treatment, respiratory failure will usually occur within 10 days. If paralysis and respiratory failure has already occurred, intensive supportive treatment is required. The use of a respirator to assist with breathing will be necessary. Recovery with this type of treatment can take weeks or months. Death can occur from respiratory failure if diagnosis and treatment are delayed. Those suspected of having food-borne botulism should seek medical treatment at a hospital immediately.


  • All foods requiring refrigeration should be kept refrigerated.
  • Don’t eat food from cans that are leaking or bulging, even if the food looks and smells fine.
  • Homemade juices should be consumed immediately after preparation.
  • Avoid wrapping potatoes and other vegetables for baking in aluminum foil unless the food item will be consumed immediately after cooking or unwrapped and stored in the refrigerator after proper cooling.
  • Do not give pasteurized or unpasteurized honey to infants under the age of 1 year.
  • Safe canning and preserving in the home.
    -The work area, utensils, equipment required for canning or preserving should be kept clean for the duration of the process. Only work with fresh foods and ingredients. Wash hands prior to starting and  whenever necessary during the process.
    -Canning or preserving of low-acid foods should occur in a pressure canner. Ensure to follow the manufacturer’s instructions for the pressure canner.
    -Food items stored in oil should be refrigerated. These items should be stored refrigerated for a maximum of one week.
    -All canned and preserved food items should be dated and labelled.
    -Boiling all canned and preserved food items before eating them for 10 minutes will destroy the botulism toxin.
  • When purchasing canned or preserved food products, or food products stored in oil from a farm gate, a farmers’ market or a fair, find out where the food was produced. These types of processed food products should be produced in an inspected and approved food premise.



Botulism Fact Sheet