What happens when a person ingests mold depends on the variety of mold, as some cause allergic reactions or respiratory problems, according to the U.S. Department of Agriculture. Other molds produce mycotoxins, poisonous substances that often make the consumer sick. Some are useful in the production of food.
Molds take various appearances on food, according to USA Today. Some are fuzzy green growths while others are white spots. By the time mold appears on the surface of most foods, its roots have contaminated the food itself. Bacteria sometimes grow alongside mold in food, causing additional problems, including food poisoning.
Keeping foods covered prevents airborne mold spores from landing on them, according to the USDA. Refrigerating foods within a two-hour timeframe is also beneficial in slowing mold growth. Consuming leftovers or discarding them within a couple of days of preparation ensures there is not enough time for mold to become a problem.
The USDA recommends discarding most foods where mold is growing. Notable exceptions include hard cheeses and firm fruits and vegetables. For these foods, it is still necessary to cut at lease an inch around and an inch below the mold before consuming them. Cured meats, including salami and dry cured hams also sometimes grow mold, but on these products, washing the mold away is all that is necessary.