Lettuce, Other Leafy Greens, and Food Safety
Vegetables are an important part of a healthy, balanced 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 does not remove all germs because they can stick to the surfaces of leaves and even get inside them. If you eat contaminated raw (uncooked) leafy greens, such as in a salad, you might get sick. To prevent contamination, leafy greens should be grown and handled safely at all steps in the journey from farm to fork.
- CDC estimates that germs on produce that is eaten raw cause a large percentage of U.S. foodborne illnesses (also called food poisoning).
- Leafy greens and other vegetable row crops are a major source of E. coli O157 infections.
- Other harmful germs found on leafy greens include norovirus, Salmonella, Listeria, and Cyclospora.
Although anyone can get food poisoning, these groups are more likely to get sick and to have a more serious illness:
- Adults aged 65 and older
- Children younger than 5 years
- People who have health problems or take medicines that lower the body’s ability to fight germs and sickness (a weakened immune system)
- Pregnant women
Read these Q&As to learn more about how leafy greens get contaminated and how to lower your chance of getting sick from eating leafy greens.
How common are foodborne disease outbreaks linked to leafy greens?
During 2014 to 2018, 51 foodborne disease outbreaks linked to leafy greens (mainly lettuce) were reported to CDC. Five were multistate outbreaks that led CDC to issue warnings to the public. Among those, two outbreaks were linked to packaged salads and two were linked to romaine lettuce. The specific type of leafy greens could not be determined for the other outbreak.
The 1,406 illnesses caused by those 51 outbreaks represent only a small proportion of all illnesses caused by contaminated leafy greens in those years. That’s because most foodborne illnesses are not part of a recognized outbreak. Some outbreaks never lead to consumer warnings because the food is no longer in stores, restaurants, or homes by the time it is identified as the source. Usually the source is not identified, and people might not even suspect that their illness was caused by contaminated food. Also, most outbreaks affect people in only one state, so local or state health departments lead work to identify, investigate, and communicate about those outbreaks.
Most recently, in 2019 and 2020, CDC investigated and issued public warnings on three multistate outbreaks linked to leafy greens.
How do leafy greens get contaminated?
Germs that make people sick can be found in many environments, including in the soil, in the intestines of animals, in refrigerators, and on kitchen surfaces.
Germs can contaminate leafy greens at many points before they reach your plate. For example, leafy greens can get contaminated from animal poop in irrigation water or the field where they grow, in packing and processing facilities, in trucks when they’re transported to the store, from the unwashed hands of food handlers, and in the kitchen.
Read a study by CDC and partners on what we have learned from ten years of investigating E. coli outbreaks linked to leafy greens.
What foodborne infections are most often linked to leafy greens?
Germs that most often cause illness transmitted by leafy vegetables are norovirus, Shiga toxin-producing E. coli (STEC) such as O157, and Salmonella, according to a CDC analysisexternal icon of foodborne disease outbreaks from 1973 through 2012. Listeria and Cyclospora also cause these illnesses.
Are leafy greens safe to eat?
Millions of servings of leafy greens are consumed safely every day. However, leafy greens are occasionally contaminated enough to cause illness.
What is the best way to wash leafy greens?
Studies show that thoroughly rinsing fresh produce under running water removes some of the germs and dirt. No washing method completely removes all germs.
Check to see if your prepackaged leafy greens are labeled ready to eat, triple washed, or no washing necessary. These leafy greens do not need to be washed again. Although prewashed greens aren’t guaranteed to be safe, the washing process should have removed most contamination. All other leafy greens should be thoroughly washed before eating, cutting, or cooking.
Follow the steps below for leafy greens you plan to eat raw:
- Wash your hands for 20 seconds with soap and water before and after preparing leafy greens.
- Discard outer leaves and any torn or bruised ones.
- Rinse the leafy greens under running water and use your hands to gently rub the surface of the leaves.
- Don’t soak leafy greens in a sink filled with water. They can get contaminated with germs in the sink.
- Don’t soak leafy greens in a bowl filled with water. Contamination from one leaf can spread through the water to other leaves.
- If you do not have access to safe tap water, rinse with other drinkable water (such as filtered, bottled, or distilled water).
- Dry leafy greens with a clean cloth or paper towel.
Can I use vinegar, lemon juice, soap, or produce wash to clean leafy greens?
FDA does not recommend washing vegetables and fruit with soap, detergent, or produce washes. Do not use bleach solution or other disinfectants to wash produce.
FDA recommends using plain, running water. Kitchen vinegar and lemon juice may be used, but CDC is not aware of evidence that they are any better than running water.
What other food safety steps should I keep in mind when I select, store, and prepare leafy greens and other produce?
- Select vegetables and fruits that aren’t bruised or damaged. Make sure any pre-cut products, such as bagged salad mixes or cut produce, are refrigerated or on ice in the store and at home.
- Separate produce from raw meat, poultry, seafood, and eggs in your shopping cart, grocery bags, and refrigerator.
- Store vegetables and fruits, including pre-cut and packaged produce and salads, in a clean refrigerator with the temperature set to 40°F or below.
- Wash utensils, cutting boards, and kitchen surfaces with hot, soapy water after each use.
- Use separate cutting boards and utensils for fresh produce and raw foods that come from animals, such as meat, poultry, and seafood. If that isn’t an option, prepare produce before working with raw meat.
- Cook thoroughly or throw away any produce that comes in contact with raw meat, poultry, or seafood or their juices.
- Remove the outer layer of leaves from heads of lettuce and cabbage. Cut away bruised or damaged parts.
- Refrigerate cooked or cut produce, including salads, within 2 hours (or 1 hour if the air temperature is 90° or warmer).
Are organic leafy greens less likely to cause food poisoning than non-organic ones?
All produce, including organic leafy greens, can be contaminated with harmful germs at any point from farm to fork. CDC is not aware of any evidence that organic greens are safer.
Are hydroponic or greenhouse-grown leafy greens less likely to cause food poisoning?
Leafy greens grown using these methods also can be contaminated with harmful germs at any point from farm to fork.
How do I keep leafy greens in my garden safe to eat?
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. Minimize contact between dirty water, including storm runoff, and the edible part of your crops.
Can pets and other animals get sick if they eat contaminated leafy greens?
Some animals can get sick from some germs that also make people sick. Follow the food safety steps described above before feeding leafy greens to pets and other animals. Never feed recalled food to pets.
What should I do with 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 dispose of it properly 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 garbage can with a tight lid (so animals cannot get to 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.
What steps are industry and the government taking to make leafy greens safer?
The leafy greens industry, FDA, and state regulatory authorities have been implementing provisions of the Produce Safety Ruleexternal iconas part of the FDA Food Safety Modernization Act (FSMA). external iconThey are considering what further measures can be taken. FDA’s 2020 Leafy Greens STEC Action Planexternal icon describes the agency’s plans to work with partners to make leafy greens safer.