Each year outbreaks of gastrointestinal illness, such as vomiting and diarrhea, have been linked to fruits and vegetables contaminated with harmful bacteria, viruses and parasites.

From 1998-2008, almost 600 outbreaks of foodborne illness in the United States were linked to fresh produce. Domestic and imported produce, as well as home-grown fruits and vegetables, were implicated. The most common culprits were contaminated leafy greens such as spinach and lettuce, tomatoes and melons, but other fruits and vegetables also were implicated.

Produce can become contaminated during cultivation, harvest, processing, transport, storage and preparation. Contamination can result directly or indirectly from animals or insects, soil, water, dirty equipment and human handling.

Since you cannot see, smell or taste contamination on fresh fruits and vegetables, the Partnership for Food Safety Education recommends six steps for produce safety (See sidebar below).

Here are some additional tips for cleaning produce.

A rinse and scrub

Thoroughly rinse fruits and vegetables under running water before preparing and serving them. No washing method completely removes or kills all microbes that may be present, but rinsing produce with running water significantly reduces the number of microorganisms present and the risk of gastrointestinal illness.

When possible, scrub fruits and vegetables with a clean scrub brush or your hands, including produce with skins and rinds that are not eaten.

The best method for washing delicate berries is with a kitchen sink sprayer. Use a colander so you can turn the fruit as you spray.

Remove outer green leaves from items like lettuce or cauliflower before washing. Trim the hull or stem from items like tomatoes, strawberries and peppers after washing.

Do not soak fruits and vegetables (such as in a sink-full of water) because one contaminated piece of produce could cross-contaminate all the others.

Do not wash fruits and vegetables with detergent or soap. These products are not approved or labeled by the U.S. Food and Drug Administration for use on foods. You could ingest residues from soap or detergent absorbed on the produce that also could make you ill.

The U.S Department of Agriculture does not recommend the use of chemical rinses and other treatments marketed for washing raw produce because the safety of their residues has not been evaluated and no studies to date suggest that they are more effective than running water.

There is no need to wash packaged fruits and vegetables labeled “ready-to-eat,” “washed” or “triple washed.” If you choose to wash these products, be sure the area is free of all contaminates.

Washing produce before storing it (that is right after harvest or purchase) may actually promote bacterial growth and speed up spoilage. As a result, it is often recommended to wait and wash fruits and vegetables until just before use.

If you choose to wash produce before storage, dry it thoroughly with clean cloth or paper towels before storing.

Six steps for produce safety

STEP 1: CHECK. Check to be sure that fresh fruits and vegetables are not bruised or damaged. These spots allow harmful microorganisms to get into produce and multiply. Check that fresh-cut fruits and vegetables, such as packaged salads or cut melons, have been refrigerated.

STEP 2: CLEAN. Before handling fruits and vegetables, wash your hands with warm water and soap for at least 20 seconds. Clean all surfaces and utensils that will touch fresh fruits or vegetables with hot water and soap, including cutting boards, counter tops, peelers and knives.

STEP 3: SEPARATE. Keep fresh fruits and vegetables separate from household chemicals and raw foods such as meat, poultry and seafood while shopping, storing and preparing. Do not use the same cutting board without cleaning with hot water and soap in between uses.

STEP 4: RINSE. Shortly before eating fresh fruits and vegetables, rinse them under running tap water. Dry with a clean cloth or paper towel.

STEP 5: CHILL. Refrigerate all cut, peeled or cooked fresh fruits and vegetables within two hours of preparing. Keep your refrigerator at or below 40 degrees.

STEP 6: THROW AWAY. Throw away fresh fruits and vegetables that have not been refrigerated within two hours of cutting, peeling or cooking. Remove and throw away bruised or damaged portions of fruits and vegetables, and any fruit or vegetable that will not be cooked if it has touched raw meat, poultry or seafood.

— from Partnership for Food Safety Education

Jeanette Stehr-Green is a Washington State University-certified, Clallam County Master Gardener.