How safe is the American food supply? Very safe, if you ask the experts—probably the safest in the world. But, even so, if food isn't handled correctly and becomes contaminated by disease-causing bacteria (pathogens), it can still make you sick.

"All, or nearly all, of foodborne illnesses are preventable," says Janet Anderberg, registered sanitarian and senior environmental health specialist for the Seattle-King County Department of Public Health.

"One of the difficulties with handling food correctly," says Anderberg, "is that bacteria can't be seen with the naked eye. As a rule, we tend to pay attention to those things we can see. We tend to not eat food if it is a different color or if it has mold. We also tend to not eat food if it smells bad." But, states Anderberg, "you can't assume that food isn't contaminated just because you might not be able to see or smell any signs of bacteria."

Most of the disease-causing bacteria reside on the outside of food. This is especially true of meat, poultry, and fish. If meat is cut up or ground, the bacteria now has an additional surface on which to grow.

"That's why it's so important to clean kitchen counters, knives, cutting boards, and hands before and after food preparation," says Marjorie Davidson of the United States Department of Agriculture's Food Safety and Inspection Service-Food Safety Education Office.

For the most part, bacteria are rendered harmless when meat, fish, or poultry is fully cooked to medium or well-done temperatures. Roasts, notes Anderberg, are fine to eat, even if cooked rare. The bacteria on a whole piece of meat are found only on a limited number of surfaces, not the multiple surfaces of ground meats.

In the grinding process, the meat becomes inverted—the middle becomes the outside and the outside becomes the middle. Grilling the hamburger kills the surface pathogens that are present, but doesn't necessarily kill those lurking on the inside unless the meat is fully cooked.

Seasonal Factors

According to Anderberg, the largest number of foodborne illnesses are reported in the summer. These cases are due primarily to food that has been handled inappropriately.

At a barbecue, for instance, hamburgers are often brought out to the grill on a platter. If the platter is used again to bring the cooked food to the table, without being washed in between, the cooked hamburgers served on that platter may become contaminated.

The cheese on a cheeseburger can become contaminated if it's brought to the grill on the same platter as the raw hamburger. Although the cheese cooks on top of the hamburger, it isn't fully cooked.

Some foodborne illnesses have been traced to the lettuce and cheese on a burger. In one case, the lettuce and cheese were stored under the hamburger, which was on the top shelf, and the meat dripped on the lettuce and the cheese.

Davidson recommends that meat, poultry, and seafood be stored on a plate in the refrigerator, either in its designated compartment or on the lowest shelf possible. This helps prevent contamination of foods that won't be fully cooked, says Davidson.

Shopping and Storing Food

Although food may still be good after it is out of date, food manufacturers and processors can't guarantee its safety.

When shopping for food, Davidson recommends buying foods within "code dates" or the "use by" dates. Although food may still be good after it is out of date, food manufacturers and processors can't guarantee its safety. Bacterial contaminations are both a function of time and temperature. The older a product is, the more likely it is to be contaminated.

For refrigerated foods such as meats, Davidson suggests buying only those that are cold to the touch. Food that is cold to the touch has been kept at temperatures close to 40° F (4ºC), and out of the danger zone (50°F-140° F) [10ºC-60ºC]. Frozen foods should be "solid as a rock" says Davidson.

Once food has been purchased, it should be stored as quickly as possible, agree the experts. Don't let perishables sit in the trunk of your car. Bacteria generally don't grow well under refrigeration, and in some cases, bacterial growth is severely retarded. If you don't plan on eating leftover food within four hours, then refrigerate it.

Experts also agree that frozen foods should be thawed either in the refrigerator or in the microwave. Thawing frozen foods on top of the counter allows the frozen surface to thaw long before the core. This provides a nice, warm, moist environment that enhances bacterial growth.


Hands should be washed in hot, soapy water for before and after food preparation.

Handwashing is an important factor in food contamination. While it may be a nuisance to wash your hands frequently, it can prevent cross-contamination between different foods or kitchen utensils.

E. coli is present in the intestinal tract of most people and is easily transferable, especially when personal hygiene is not emphasized. If you use the bathroom without washing your hands, you can contaminate other things you touch.

Towels used for drying the hands should also be clean, to prevent recontaminating the hands. Paper towels work well.

Clean Is Key

"Make sure sponges, towels, and cloths are all clean," reminds Davidson. These items are generally moist, and at room temperature, ideal breeding grounds for bacteria. You can keep your sponges bacteria-free by washing them in the dishwasher every time you wash a load of dishes.

When you're done preparing one food, clean your work surface and knives before starting another, says Davidson. Wash hands again before starting to prepare the next food. "Recontamination is a major problem in food contamination," remarks Anderberg.

Also wash fruits and vegetables. Rinse them under running tap water. For leafy vegetables, remove and throw out the outermost leaves. Since bacteria grows well on the cut surface of fruits and vegetables, do not contaminate these foods when slicing them. And avoid leaving cut produce out for many hours.

Keep Cool

Using a special refrigeration thermometer, check the temperature of your refrigerator at least once a week. The freezer should be at 0°F (-18ºC) and the refrigerator itself should be below 40°F (4ºC) without freezing foods such as lettuce and milk. In addition, the thermometers should be checked periodically for accuracy.

Food safety truly does begin at home. So practice good food safety handling practices to enjoy your meal!