Lettuce, Other Leafy Greens, and Food Safety

Vegetables are an important part of a healthy diet. Leafy vegetables (called leafy greens on this page), such as lettuce, spinach, cabbage, kale, and bok choy, provide nutrients that help protect you from heart disease, stroke, and some cancers.

But leafy greens, like other vegetables and fruits, are sometimes contaminated with harmful germs. Washing leafy greens does not remove all germs. That’s because germs can stick to the surface of leaves and even get inside them. If you eat contaminated leafy greens without cooking them first, such as in a salad or on a sandwich, you might get sick.

• Many foodborne illnesses in the United States are caused by germs on vegetables and fruits that people eat raw.
• Harmful germs sometimes found on leafy greens include E. coli, norovirus, Salmonella, Listeria, and Cyclospora.

Although anyone can get a foodborne illness, sometimes called food poisoning, some groups of people are more likely to get one and to have a serious illness. These groups include:

• Adults aged 65 and older
• Children younger than 5 years
• People who have a weakened immune system because of a health problem or treatment that lowers the body’s ability to fight germs and sickness
• People who are pregnant

Eating Leafy Greens

Millions of servings of leafy greens are eaten safely every day in the United States. But leafy greens sometimes have enough germs on them to make people sick if they eat the greens raw, such as in a salad. To reduce your chance of getting sick, always handle and prepare leafy greens safely before eating or serving them.

Animals sometimes get sick from some germs that make people sick. Always handle and prepare leafy greens safely before feeding them to pets and other animals. Never feed recalled food to pets or other animals.

Handling and Preparing Leafy Greens Safely

Prewashed greens don’t need to be washed again. If the label on a leafy greens package says any of the following, you don’t need to wash the greens:

• Ready to eat
• Triple washed
• No washing necessary

Although prewashed greens sometimes cause illness, the commercial washing process helps remove germs that can be removed by washing.

Leafy greens that are not prewashed should be washed thoroughly before eating, cutting, or cooking.

The best way to wash leafy greens is by rinsing them under running water. Studies show that this step removes some of the germs and dirt on leafy greens and other vegetables and fruits. But no washing method can remove all germs.

Follow these steps to wash leafy greens:

• Wash your hands for at least 20 seconds with soap and water before and after preparing leafy greens.
• Get rid of any torn or bruised leaves. Also, get rid of the outer leaves of cabbages and lettuce heads.
• Rinse the remaining leaves under running water. Use your hands to gently rub them to help get rid of germs and dirt.
• Dry leafy greens with a clean cloth or paper towel.

Rinsing leafy greens under running water is the best way to wash them. Do not soak leafy greens. If you soak them, germs from one leaf can spread to the others. Also, if you soak them in the sink, germs in the sink can contaminate the greens.

Use plain running water to wash leafy greens and other vegetables and fruit. Do not wash leafy greens with vinegar, lemon juice, soap, detergent, or produce wash. Kitchen vinegar and lemon juice will not harm leafy greens or other produce, but CDC is not aware of studies that show vinegar or lemon juice are any better than plain running water.

Soap, detergent, or produce wash are not any better than plain running water and may leave soap or chemicals on food. Never use a bleach solution or other disinfectant to wash produce.

Other food safety steps for selecting, storing, and preparing leafy greens and other produce

• Select leafy greens and other vegetables and fruits that aren’t bruised or damaged.
• Make sure pre-cut produce, such as bagged salad or cut fruits and vegetables, is refrigerated or on ice at the store.
• Separate produce from raw meat, chicken and other poultry, seafood, and eggs in your shopping cart, grocery bags, and refrigerator.
• Store leafy greens, salads, and all pre-cut and packaged produce in a clean refrigerator with the temperature set to 40°F or colder.
• Use separate cutting boards and utensils for produce and for raw meat, poultry, seafood, and eggs. If that isn’t an option, prepare produce before working with raw meat.
• Wash utensils, cutting boards, and kitchen surfaces with hot, soapy water after each use.
• Cook thoroughly or throw away any produce that touches raw meat, poultry, seafood or their juices.
• Refrigerate cooked or cut produce, including salads, within 2 hours (or within 1 hour if the food is in temperatures hotter than 90°F, like in a hot car or at a picnic).

Germs, Outbreaks, and Recalls

Germs that make people sick can be found in many places, including in the soil, in human or animal poop, in refrigerators, and on kitchen surfaces.

Germs can contaminate leafy greens at many points before they reach your plate. For example, germs from animal poop can get in irrigation water or fields where the vegetables grow. Germs can also get on leafy greens in packing and processing facilities, in trucks used for shipping, from the unwashed hands of food handlers, and in the kitchen. To prevent contamination, leafy greens should be grown and handled safely at all points from farm to fork.

In 2014–2021, a total of 78 foodborne disease outbreaks linked to leafy greens (mainly lettuce) were reported to CDC. CDC issued outbreak notices for several outbreaks linked to leafy greens during this time period.

Most foodborne illnesses are not part of a recognized outbreak. The 2,028 illnesses, 477 hospitalizations, and 18 deaths associated with outbreaks linked to leafy greens reported to CDC in 2014–2021 represent only a part of illnesses caused by contaminated leafy greens during those years.

CDC does not warn the public about every foodborne outbreak, including ones linked to leafy greens. Some reasons include:

• Many sources of foodborne outbreaks are never identified.
• By the time a source is identified, it might no longer be in stores, restaurants, or homes. This can happen with foods that are perishable (foods that spoil or go bad quickly), such as leafy greens.
• Most outbreaks affect people in only one state, so local or state health departments work to identify, investigate, and communicate about those outbreaks. CDC usually communicates only about outbreaks that affect people in more than one state or involve a food sold in more than one state.

Investigating outbreaks linked to leafy greens can be especially challenging. These outbreaks often go unidentified or unsolved.

Handling leafy greens that are part of a recall

• Never eat, serve, or sell food that has been recalled, even if some of it was eaten and no one got sick.
• Return the recalled food to the store or throw it away at home.
  • Throw out the recalled food and any other foods stored with it or that touched it.
  • Put it in a sealed bag in an outside trash can with a tight lid (so animals cannot eat it).
  • If the recalled food was stored in a reusable container, wash the container in the dishwasher or with hot, soapy water.
• Follow CDC’s instructions for cleaning your refrigerator after a food recall.

Organic, Hydroponic, and Home-Grown Leafy Greens

All kinds of produce, including organic leafy greens, can be contaminated with harmful germs. This contamination can happen at any point from farm to fork. CDC is not aware of any evidence that organic greens are safer.

Learn about some outbreaks linked to organic foods.

Leafy greens grown using hydroponic or greenhouse-grown methods also can be contaminated with harmful germs at any point from farm to fork.

Learn about an outbreak linked to greenhouse-grown leafy greens.

Home gardens can be an excellent source of fruits and vegetables. Follow these tips to help prevent food poisoning:

• Plant your garden away from animal pens, compost bins, and manure piles.
• Water your garden with clean, drinkable water.
• Keep dirty water, including storm runoff, away from the parts of plants you will eat.

Learn about raised bed gardening [PDF – 1 page].

Looking to the Future

CDC is collaborating with FDA, universities, and food producers to investigate factors that contribute to leafy greens contamination.

The leafy greens industry, FDA, and state regulatory authorities have been implementing provisions of the Produce Safety Rule as part of the FDA Food Safety Modernization Act (FSMA). They are considering what further measures can be taken. FDA’s 2020 Leafy Greens STEC [Shiga toxin-producing E. coli] Action Plan describes the agency’s plans to work with partners to make leafy greens safer.