Food safety tips for vegetables and herbs in oil

Some people like to store vegetables and herbs in oil to extend their shelf life or to flavor the oil. Some common foods used for this are garlic, onions, sun-dried tomatoes, hot peppers, mushrooms and various herbs.

Most foods stored in oil are low-acid and need to be properly prepared or they can cause serious illnesses like botulism. Protect your family by following some simple tips.

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Health risks

Some people can get a foodborne illness, also known as "food poisoning", and not even know they have it. Food poisoning can be caused by eating foods that are contaminated. Most vegetables and herbs are low-acid foods and if they are not prepared, bottled or refrigerated properly they can cause foodborne illnesses like botulism.

Botulism is a serious and sometimes fatal illness you can get from eating improperly prepared, canned or bottled food. Botulism is caused by a toxin produced by the bacteria Clostridium botulinum (C. botulinum). Botulism bacteria grow in a moist, oxygen-free environment so improperly stored vegetables and herbs in oil can provide ideal conditions for it to multiply and produce the toxin.

You should see a health care professional and contact your local public health unit as soon as possible if you think you have botulism or another foodborne illness.


  • Examine vegetables and herbs carefully and avoid buying items that are bruised or damaged.
  • If buying pre-cut or ready-to-eat vegetables and herbs, be sure they have been properly refrigerated at 4°C or below. This means they should be displayed in a refrigerated container and not just sitting on top of ice.
  • If you use reusable grocery bags or bins, make sure to use a separate bag or bin for raw meat, poultry, fish and seafood. Label the bag or bin with the type of food it carries and wash them frequently.
  • Commercially-prepared products stored in oil that contain an acid like vinegar or salt in their list of ingredients are generally considered safe. These products are processed using technology that is not usually available at home.
  • Make sure that the products stored in oil were prepared under strict food safety conditions.
  • If in doubt about the ingredients in a particular product, consumers can contact the manufacturer.


  • Wash your hands with soap and warm water for at least 20 seconds.
  • Wash your fresh vegetables and herbs gently under cool, running, drinkable water before eating or cooking them.
  • Use one cutting board for produce, and a separate one for raw meat, poultry and seafood.
  • Use paper towels to wipe kitchen surfaces, or change dishcloths daily to avoid the risk of cross-contamination and the spread of bacteria and avoid using sponges, as they are harder to keep bacteria-free.
  • Sanitize countertops, cutting boards and utensils before and after preparing food. Use a kitchen sanitizer (following the directions on the container) or a bleach solution (5 ml household bleach to 750 ml of water), and rinse with water.
  • Sterilize containers and closures prior to filling with oil.
  • Clean during all stages of the bottling process to avoid cross-contamination.


  • Label and date all home-prepared foods along with a list of the ingredients used.
  • Always keep vegetables and herbs stored in oil in the refrigerator to slow bacterial growth.
  • Make sure your refrigerator is set at 4 °C (40 °F) or lower. This will keep your food out of the temperature danger zone (between 4 °C (40 °F) to 60 °C (140 °F)) where bacteria can grow quickly.
  • Never keep vegetables and herbs stored in oil at room temperature.
  • Use your oil within one week of making it. Throw out any oil that is left over.
  • Check the list of ingredients, when they were prepared and discard them if they are more than a week old.
  • Discard any product that is leaking or if you suspect they have been tampered with. If in doubt, throw it out!

Did you know?

There usually aren't any obvious signs that your oil is spoiled. You will not be able to tell if it is dangerous, because it will still look, smell, and taste the same.

How the Government of Canada protects you

The Government of Canada is committed to food safety.

Health Canada establishes regulations and standards relating to the safety and nutritional quality of foods sold in Canada. Through inspection and enforcement activities, the Canadian Food Inspection Agency verifies that food sold in Canada meets Health Canada's requirements.

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