You should not use soap, detergents or bleaches on fruits or vegetables, according to the FDA. Instead, rinse them thoroughly under running water. If you must remove surface dirt, use a small vegetable brush. Cut out damaged or bruised areas.

Potatoes that are green under the skin have been exposed to sunlight. The green is caused by the formation of solanine and is not safe to eat. Also throw out any potatoes that have sprouted or that have large, protruding eyes. These actually are the roots of the potato forming. A potato with one or two small eyes is safe to eat if you remove the eyes.

Tomatoes that are leaking have spoiled and should not be eaten. The bacteria found in rotting tomatoes can cause stomach upset and diarrhea.

Packaging is meant to protect the food item from bacteria and other contamination. If a container is damaged, the food inside could be contaminated.

This date is used to indicate when a food may begin to decline in flavor or quality. It does not refer to safety. "Expiration Date" indicates the last date that a food should be eaten. "Sell By" and "Use By" are similar in purpose to the "Best If Used By" date. If you see a food item at a store that has passed its "Best If Used By" date, you might want to pass it up for something fresher.

"Sous vide" means "under vacuum." These plastic pouches contain either raw foods or foods that have been partially cooked, then sealed in a vacuum before processing with heat. This kind of packaging should be refrigerated, according to the FDA, and should keep three to four weeks. When you are ready to eat it, the pouch is heated in boiling water.

When you buy hot cooked food, you should eat it within two hours to avoid harmful bacteria that begin to multiply. If you aren't eating the food within two hours, and want to keep it hot, the FDA says that you should keep the food in the oven at or above 140 degrees. Cover food in the oven to keep it moist. If you want to bring home leftovers from a restaurant meal, but don't expect to be home within two hours, it's safer to pass up the leftovers, according to the FDA. Cold foods should get similar care. If you are not eating cold food within two hours after buying or preparing it, put it in the refrigerator or freezer for later use.

If the leftovers are perishable -- an egg salad sandwich, for instance -- and you did not have a cold pack in your lunch bag, you should throw out the sandwich. Foods that have been kept properly cold, or that are nonperishable, can be saved for another meal. When in doubt, however, you should discard a food item rather than eating it.

Animal foods are rich in proteins, which are an important source of nutrients for some bacteria, according to the FDA. Also, the bacteria that live in cattle or chickens, for instance, often can be found in the food products made from them. Any bacteria found in these raw foods can contaminate other foods if cutting surfaces, hands, knives and dishes are not kept clean, according to the FDA.

Salmonella bacteria can be found inside raw eggs because an infected hen can transmit the bacteria to egg before the shells are formed, according to the FDA. For safety, eggs should be cooked until the yolks and whites are firm. Scrambled eggs should be firm throughout. Boiled eggs should be cooked for seven minutes.