According to Google Trends, the search term “food I can reheat” has increased by 1328% in the past week. Whether it’s to save food, save money, or not heat up a kitchen in hot weather, Americans have leftovers on their minds.

In fact, storing leftovers is big business. Globe Enewswire estimated the U.S. food storage container market to be $5.3 billion in 2022 and increasing.

People are buying storage containers, so it follows they’re reheating the food they’re storing. Is that a safe practice? The Centers for Disease Control and Prevention (CDC) reports that about 48 million Americans suffer from food poisoning yearly, with 128,000 hospitalizations and 3,000 deaths. It’s unknown how many of these cases resulted from improperly reheating leftover food, but the incidence of food poisoning is a statistic worthy of consideration.

The Reheating Hit List

Which leftovers are the most likely to harbor bacteria growth and are the riskiest to reheat? Food researchers at Menu Price conducted a study and came up with the top eight foods that shouldn’t be reheated or should be treated with caution.

Rice

Rice is especially prone to growing bacteria once it’s been cooked. The trouble is, reheating the tainted rice doesn’t kill the bacteria. According to the National Health Service, storing leftover rice properly is the key to safe reheating. The NHS recommends cooling rice quickly and storing it in the refrigerator for no longer than 24 hours. Cooked rice should be reheated until it is hot all the way through and should not be reheated more than once.

Potatoes

Anyone who has been ill after eating potato salad at a picnic is probably aware of the dangers of potatoes. They’re a breeding ground for Clostridium botulinum when cooked and left at room temperature, especially if baked and wrapped in aluminum foil. The low-oxygen atmosphere creates a perfect environment for C. botulinum to grow.

As with rice, the key is storing cooked potatoes properly. They should be taken from the foil and put in the refrigerator to cool down immediately. They should be reheated until they reach a safe food temperature of at least 135 degrees Fahrenheit.

Eggs

Reheating eggs can affect their texture, as well as produce harmful bacteria. This is most common if the egg dish has been left at room temperature for too long. Healthline recommends cooking eggs to at least 165 degrees Fahrenheit, immediately refrigerating leftovers, and reheating those leftovers to 165 degrees again.

Spinach and Leafy Greens

Reheating these healthy vegetables may not cause immediate food poisoning, but they can still become toxic. Menu Price reports that reheating leafy greens increases nitrosamines, which can cause cancer. Michelle Darrisaw from My Recipes recommends using leftover spinach in a cold pasta salad or another dish served cold to reduce the risk of consuming nitrosamines.

Mushrooms

According to Menu Price, mushrooms are prone to changes from microorganisms that may cause an upset stomach. Cooked mushrooms shouldn’t be left at room temperature for more than two hours, and should not be stored in the refrigerator longer than 24 hours, reports Business Insider. They should be reheated until piping hot.

Seafood

Seafood has food safety issues before and after cooking. Before cooking, the Food and Drug Administration (FDA) recommends fresh seafood should be stored in the refrigerator no more than two days after purchase or immediately frozen. It should also be refrigerated soon after cooking.

Reheated seafood should reach a temperature of at least 165 degrees Fahrenheit. However, many experts recommend it should be served cold to avoid the risk of food poisoning.

Oils

Cooking oil may be an unexpected item on this list. However, several commonly used oils will go rancid, including walnut, avocado, and grapeseed. Some of these oils can release harmful substances if recooked, while others may just taste bitter or burned.

According to SafeBeat, cooking oils should be kept in a cool, dark place to extend their lives. Oils should be thrown out when they smell old or rancid or change color or consistency.

Turnips

As more Americans add root vegetables to their diets, turnips are appearing in recipes. The Menu Price experts recommend that these vegetables be consumed cold within 24 hours of being cooked and refrigerated immediately. Like their greens, reheated turnips can contain cancer-causing nitrosamines.

Food Safety

Good cooking incorporates a knowledge of food safety which, according to the U.S. Department of Agriculture (USDA), boils down to keeping hot food hot and cold food cold. This means hot foods should stay at 140 degrees Fahrenheit (or warmer), and cold foods should be 40 degrees or colder. The range between 40 and 140 degrees is where danger lurks, and harmful bacteria grow.

The USDA and CDC offer free resources concerning food safety and prevention of foodborne illnesses, so even novice cooks can be confident their food is safe.

This article was produced by Media Decision and syndicated by Wealth of Geeks.