Mold is not entirely safe. It can make even healthy people quite unwell.

The World Health Organization says that a kind of mold called mycotoxins is even linked to cancer.

The USDA says that most foods with mold are too dangerous to eat. This is the case when food is covered in mold, even if you can cut off the affected part. The only exceptions to this are long-lasting hard cheeses, cured meats, and some fruits and vegetables.

If you see mold on any fresh meat, poultry, or seafood, you must throw the whole product away.

Mold from the Penicillium genus — the same kind of mold that the antibiotic penicillin comes from — helps give cheeses like Camembert, Brie, and Roquefort their exceptional taste and look. The molds used here behave the same way as others, but the conditions in which they are produced and developed are carefully controlled to stop them from producing harmful mycotoxins.

Mold grows on food in the same way that black mold grows in damp parts of homes. The spores land on food that is just right for them.

You can’t stop mold from reaching your food. All the food you keep in your pantry, refrigerator, and freezer comes into contact with outside air. Airtight packaging helps reduce exposure, but no packaging can eliminate it.

But there are things you can do at home to prevent mold from eating your food before you have a chance to eat it. First, don’t change the airtight containers. Leave them until you are ready to use the food inside. When shopping for fresh produce, it’s best to buy items that are in season, locally grown, and in small quantities.

Keeping your kitchen, refrigerator, and food containers as clean as possible can help reduce the presence of mold spores. It’s also important to consider temperature because mold grows well in warm, damp places.

The food industry tries very hard to stop mold from growing during production, but it’s impossible to prevent the risk entirely. You can’t stop mold from growing in your home, either. If some of your food starts to go moldy, don’t worry. Not all mold is harmful. You can cut away the moldy part and eat the rest. If it’s awful, throw it away.