Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension

Extension is almost done building a new website! Please take a sneak peek or read about our redesign process.

Extension > Food > Food Safety > Preserving and Preparing > Safe Meals > Are molds on foods dangerous?

Print Icon Email Icon Share Icon

Preparing Safe Meals

Are molds on foods dangerous?

Carol Ann Burtness

moldy tomatoes

National Center for Home Food Preservation

Do you notice mold growing on some of the products in the back of your refrigerator? If yes, it’s probably time to clean out the refrigerator!

What is mold?

Molds are tiny fungi that live on plants or animals and can be carried by air, water or insects. Moldy foods may also have other invisible bacteria growing along with the mold.

Conditions and food where mold grows best

Molds grow best in warm, humid conditions, but can also grow at refrigerator temperatures. Molds tolerate salt and sugar and can survive on high-acid foods like jams, pickles, fruit, tomatoes and cured salty meats such as bacon, ham and bologna.

Is mold dangerous?

Some molds are dangerous because they cause allergic reactions and respiratory problems in susceptible people. Some molds also produce mycotoxins that are poisonous substances that can make people sick. When a food looks moldy, the mold spores have already invaded deeply into the product. Mycotoxins are most often contained in and around these spores but may also spread throughout the food.

Tips to control mold

Control mold by keeping everything clean. Mold spores from moldy foods can build up in the refrigerator, dishcloth and other cleaning utensils. Follow these tips to control or reduce mold:

What to do with moldy food

If you see moldy food, do not smell or sniff it. Throw out the food by putting it into a small paper bag or wrapping it in plastic and throwing it in a covered trash can away from children or animals. Clean the refrigerator or pantry, especially in the area where the food was stored and check nearby items that the moldy food might have touched. Mold spreads quickly in fruits and vegetables.

In general, it’s best to throw out any food that has become moldy, with the exception of hard cheese, hard salami, dry cured ham and firm produce like carrots and bell pepper. Because it’s difficult for molds to deeply penetrate these products, they can be saved if they are not heavily affected by mold. To save the product, cut off at least 1 inch around and below the mold spot, keeping the knife out of the mold to prevent cross contaminating other parts. After trimming off the mold, re-cover in fresh wrap.

Reviewed by Suzanne Driessen 2017

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy