Each year, one in six Americans becomes sick from eating contaminated food. But while outbreaks of food-borne illness linked to processing plants or imported products capture the public’s attention and raise fears about the safety of the food supply, as many as 70 percent of food poisoning cases originate in the kitchen.

People, not products, are the main cause of food-borne illnesses, and they can be avoided by following certain basic principles of food safety.

Unfortunately, some of the best advice, like using disposable paper towels in place of reusable cloths and sponges, butts headfirst against modern efforts to be “green.” Other measures, like discarding leftovers after two days, are antithetical to the “waste not, want not” philosophy I was raised on. (Just before writing this paragraph, I reheated and ate a plate of delicious well-cooked leftovers that I had prepared for a dinner party six days earlier and promptly refrigerated.)

Still, there are many noncontentious steps that can be taken to minimize the risk that anyone will be sickened by the food you buy and prepare.

SHOPPING Seek stores that are clean, well-organized and appear to have high product turnover: you can tell partly by checking the expiration and sell-by dates on the goods. Reject expired products and those in damaged or leaking packages. Don’t buy more perishables than you can use.

Pick up dry products first, then those that should be kept cold or frozen. In warm weather, or if there will be delays getting home, bring a cooler with ice or a freezer pack to keep items cold. Put all raw meats, poultry and fish in separate plastic bags before placing them in the shopping cart. At checkout, have them bagged separately from the dry foods and produce.

STORAGE Separate raw meats, poultry and fish from other foods in the refrigerator, placing them on the lowest shelf, in a bin or on a tray to prevent dripping. Freeze meats that will not be cooked within two or three days. Use eggs within three to five weeks of purchase. In the pantry, place newly bought products behind older ones, which should be used first.

Place thermometers in the refrigerator and freezer, if they are not built in. Make sure the temperatures are at or below 40 degrees in the refrigerator and 2 degrees in the freezer. Defrost all uncooked foods in the refrigerator, the microwave or in a bowl of ice water. PREPARATION Start by washing your hands with soap and warm water. Pin long hair back or cover it; remove rings and bracelets, and put on a clean apron.

If you should sneeze, have to blow your nose or use the bathroom while working with food, wash your hands again. Half of people harbor the infectious Staphylococcus bacteria in their nasal passages. Also wash if you pet the dog or hand-feed it while preparing food.

Wash all produce, including melons, lemons and limes and fruits that will be peeled, before picking up a knife. If the fruit’s surface contains infectious organisms, they can spread to its flesh when the fruit is cut.

Although some suggest that poultry and meats not be rinsed lest they contaminate the sink, I find that hard to avoid. Instead, I rinse them, then clean the sink with a bleach spray. And I do use clean paper towels to dry raw food.

Work on well-washed cutting boards, using separate ones for produce and raw animal products. I use plastic boards that can be cleaned with a bleach spray or in the dishwasher, but wood is fine as long as all implements and boards are washed immediately after each chore. Never reuse an unwashed knife, plate or board on cooked food that was in contact with raw food without washing it first. Cross-contamination from raw to cooked food is a common cause of food-borne illness.

If making dishes a day or more ahead, cover them well, chill them quickly, and keep them cold until it is time to reheat or serve.

COOKING You can’t always tell if a food is contaminated by its appearance: foods containing harmful organisms can look, smell and taste O.K. A goal of cooking is to destroy most infectious organisms.

It’s best to use a food thermometer and to heed recommended final temperatures when preparing meats, poultry, fish and seafood, and eggs. Whole cuts of beef, veal and lamb should be cooked to an internal temperature of 145 degrees, followed by a three-minute rest off the heat; pork and fresh ham should reach 145 degrees, followed by a three-minute rest (heat precooked ham to 140 degrees).

Ground meats should reach 160 degrees; poultry (whole or ground), 165 degrees and fish, 145 degrees (or until it is opaque and separates easily with a fork). Shrimp, lobster and crab should be cooked until the flesh is pearly and opaque. Clams, mussels and oysters should be cooked until the shells open, and scallops until the flesh is milky white or opaque and firm. Cook eggs until the yolk and white are firm, and cook egg dishes to 160 degrees.

If a recipe calls for raw or partly cooked eggs in a dish that will not be cooked (like eggnog, mayonnaise or Caesar salad dressing), use only pasteurized eggs, which are available in most large markets.

If you taste a dish while cooking, use a clean spoon each time.

If serving foods buffet-style over a period of hours, use hot plates or cold trays. Leftovers should be refrigerated as soon as possible. Reheat leftover meats and other animal products to 165 degrees.

CLEANING You don’t have to become a clean freak; some exposure to infectious organisms is necessary for a healthy immune system. But do take steps to reduce the risk of food-borne illness.

Kitchen sponges and dishcloths are notorious for harboring and breeding germs. Wash them often in the dishwasher or in the sink with hot, soapy water, or clean them with a bleach solution. Never wipe the floor with sponges used on countertops and food preparation equipment.Consider investing in a large package of microfiber cloths. Use separate cloths for the floor, counters and to dry utensils. Put soiled cloths in the laundry.

When hand-washing dishes and pots, use very hot water and put them on a rack to air-dry. Damp dish towels can harbor bacteria.

Thoroughly clean the refrigerator, stovetop and countertops often. I use a bleach solution on most surfaces, especially those that come in contact with foods.

Personal Health

Jane Brody on health and aging.