Signs of Botulism-Contaminated Food

With home canning, be sure to cook your food to the proper temperature to kill the bacteria.
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Botulism is a rare but serious foodborne illness most commonly caused by the bacteria Clostridium botulinum. Spores of this bacteria are naturally found in dirt and dust but are usually dormant. When given the right conditions, however, these spores can transform into an active bacteria and produce a deadly toxin.


Eating foods infected with this nerve toxin can cause paralysis and death if not treated, but there are steps you can take to avoid consuming foods contaminated with botulinum.

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Understand How Botulinum Grows

Botulinum spores grow if given the optimal conditions — which is a low or no-oxygen environment, some moisture and typically a temperature range between 40 and 120 degrees Fahrenheit.


In addition, low-acid foods, including most vegetables, figs, meat, chicken and fish, and foods that are low in sugar and salt are more likely to support the growth of botulinum.

Understand and Avoid High-Risk Foods

Because they're stored at room temperature and in a low-oxygen environment, home-canned, preserved or fermented foods are the most common culprits in botulism outbreaks. Historically, other foods contaminated with this toxin include fermented fish, herb-infused oils, cheese sauce and foil-wrapped baked potatoes that have not been stored at the correct temperatures, bottled garlic and foods that have been kept warm and not exposed to air for extended periods of time.


Honey is also a source of botulinum spores and poses a risk to infants, as their immature digestive systems can allow toxin production and cause infant botulism. Because of this risk, infants under the age of 1 should not be fed honey.

Inspect Canned or Jarred Foods

Because home-canned and rarely commercially canned foods can be a source of the botulinum toxin, inspect canned or jarred foods for irregularities before opening. Don't purchase or open a product if the container is damaged or cracked or if it's leaking, has bulges or is swollen.


Read more: Expiration Dates on Canned Foods

If you open a container and the food smells bad or is foamy or if the food is moldy or discolored, don't consume it. Food tainted with this toxin may not smell or taste bad. So if you suspect the food is contaminated, don't taste it — as even small amounts of the toxin can cause illness.


When in Doubt, Safely Discard

If a friend, neighbor or relative gives you home-canned foods, be selective about what you choose to eat or feed your family. In order for these foods to be safe, proper equipment needs to be used and established procedures need to be followed.


For example, the only way to process low-acid foods at temperatures high enough to kill botulinum spores is to use a pressure cooker or pressure canner and to follow the recommended recipe, including heating and cooling times.

In addition, home-canned foods should be stored between 50 to 70 degrees Fahrenheit, and most types of canned foods should be consumed within a year. If you're not confident the food was canned or stored properly or if you don't know the source of the home-canned foods, the safest decision is to not consume it.


Read more: Canned Food Poisoning Symptoms

How to Discard Contaminated Food

The Centers for Disease Control and Prevention outlines safe disposal procedures for any foods you suspect of botulinum contamination.

  • Handle the container carefully using rubber or latex gloves, taking steps to avoid spills or splashes to the skin.
  • Seal the food container in a sealable bag; then wrap another sealable bag around the first and tape to secure it.
  • Place it in nonrecyclable trash, out of the way of other people or animals.
  • Do not pour possibly contaminated food into the toilet or down the garbage disposal.
  • Clean any spills with a solution of 1/4 cup bleach and 2 cups of water and discard any sponges, washcloths or clothes that may have come in contact with the contaminated food.
  • Wash your hands for two minutes with soap and running water when you're done.


Infant botulism causes symptoms of poor feeding, poor muscle tone, a weak cry and low energy. Symptoms of botulism can begin as early as six hours after exposure and may include blurred or double vision, slurred speech, dry mouth and muscle weakness.

These symptoms can progress to difficulty breathing, paralysis and respiratory failure. Death can occur if treatment isn't initiated promptly, which includes an injection of antitoxin and ventilation to support breathing, if necessary.

If you suspect you or a family member has consumed a food contaminated with the botulinum toxin, seek immediate medical attention.



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