Health Alert: Botulism

Question: So, Doctor, how can we keep ourselves safe from foodborne illnesses when it comes to home-canned foods?

Answer: The best way to prevent foodborne botulism is by carefully following instructions for safe home canning in the USDA Complete Guide to Home Canning.

Using the right equipment for the kind of foods that you are canning. Pressure canning is the only recommended method for canning low-acid foods. Food with low acid content are the most common sources of home-canning related botulism cases. Most importantly though, “When in doubt, throw it out!”

If there is any doubt if safe canning guidelines have been followed, do not eat the food.

Question: You mentioned botulism- tell us more about what it is and what are the symptoms?

Answer: Botulism is a rare but potentially deadly illness caused by a poison most commonly produced by bacteria called Clostridium botulinum. The bacteria are found in soil and can survive, grow, and produce a toxin in certain conditions, such as when food is improperly canned. The toxin can affect your nerves, paralyze you, and even cause death.

You cannot see, smell, or taste botulinum toxin—but consuming even a small amount of food containing this toxin can be deadly.

Botulism is a medical emergency. If you or someone you know has symptoms of foodborne botulism, see your doctor or go to the emergency room immediately.

Symptoms may include the following:

-Double vision

-Blurred vision

-Drooping eyelids

-Slurred speech

-Difficulty swallowing

-A thick-feeling tongue

-Dry mouth

-Muscle weakness

Question: You stated earlier that “When in doubt, throw it out,” what should we look for when it comes to contamination of home-canned or even store-bought foods?

Answer: Home-canned and store-bought food might be contaminated with toxin or other harmful bacteria if…

1. the container is leaking, bulging, or swollen

2. the container looks damaged, cracked, or abnormal

3. the container spurts liquid or foam when opened

4. the food is discolored, moldy, or smells bad

Question: What is considered a low-acid food?

Answer: Low-acid foods have a pH level greater than 4.6, which means they are not acidic enough to prevent the growth of botulinum bacteria.

Examples are:

1. Asparagus

2. Green beans

3. Beets

4. Corn

5. Potatoes

6. Some tomatoes *

7. Figs

8. All meats

9. Fish and seafood

Tomatoes require added acid– lemon juice or citric acid – for safe home canning.

Clostridium botulinum spores are extremely difficult to eradicate at boiling-water temperatures. Most high acid food can be processed or “canned” in boiling water.

In this method, jars of food are heated and completely covered with boiling water. Low-acid vegetables and meats must be processed in pressure canners. Jars of food are placed in 2 to 3 inches of water in a pressure canner, which is then heated to a high enough temperature--at least 240 ◦F. This temperature can only be reached in a pressure canner.