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Leafy greens have been linked to numerous food poisoning outbreaks over the years. The CDC recently connected several of these to a specific strain of E. coli, though others have been caused by Salmonella, norovirus, Listeria, and Cyclospora. If this alarming fact has made you vow to wash your lettuce more thoroughly, I have some bad news: It won’t make much of a difference.
Shouldn’t produce be washed anyway?
Yes, the CDC advises washing produce. They recommend rinsing fruits and vegetables under running water, including fruits you plan to peel.
For a more thorough cleaning, you can scrub waxy vegetables with a brush. But skip the complex methods you've heard about (or seen influencers use online). Washing with salt, vinegar, baking soda, or a combination doesn't do any better than a good rinse just before eating or cooking. (And while we’re debunking myths: mixing baking soda and vinegar creates fizz, but ultimately neutralizes both chemicals, so there's no need to combine them.)
Washing doesn’t remove germs from produce
Sadly, washing alone can’t guarantee that contaminated food is safe to eat, though it can reduce the number of germs. Even soaking vegetables in bleach doesn’t easily get rid of the bacteria's biofilms.
Although the CDC recommends washing, they stress that cooking is the only reliable way to actually kill bacteria that might be on your veggies. This means there's always some risk when consuming salads or other dishes with fresh lettuce or raw vegetables.
When washing lettuce, the CDC advises using plain water—not vinegar or commercial produce washes. Rinse the leaves under running water; soaking them in a sink can transfer germs from one leaf to another, or from the sink to your food. Creating a germ-laden soup won’t help keep your food clean.
Storing vegetables in the fridge helps slow down bacterial growth since cold temperatures are not ideal for bacteria. Lettuce, salads, and cut fruits and veggies should be stored at refrigerator temperatures both in the store and at home. (By the way, make sure your fridge is between 32 and 40 degrees Fahrenheit—colder temperatures extend the shelf life of your food.)
Can pesticides be washed off?
Aside from germs, you might worry about pesticide residues. Researchers at the Connecticut Agricultural Experiment Station washed produce with running water and found that it reduced pesticide residue on 9 out of 12 tested pesticides. Interestingly, some of the removed pesticides weren’t water-soluble—indicating that they weren’t dissolved by water but physically removed by the force of running water.
A few years later, the same researchers expanded their study to test four commercial produce washes, including Fit, alongside a soap solution (1% Palmolive) and just running water. They found no significant difference between the treatments, but all the washed produce, even the one washed with only water, had less pesticide than the unwashed samples.
Though soap worked as well as the other washes in these studies—and it makes sense that it would remove oils and contaminants—no one recommends using soap. It doesn’t offer any advantage over water, and you really don’t want soap residue on your food. The CDC specifically advises against using soap when washing produce.
The suggestion from the authors is to rinse produce under running water for a minimum of 30 seconds. There's no need for soaps or cleaning agents.
It’s important to note about pesticides: even on unwashed produce, they typically aren’t found in harmful amounts. A study that tested pesticides on store-bought produce concluded that the pesticide levels were “generally well within tolerances set by the [Environmental Protection Agency].” In other words, washing may reduce some pesticide, but the amounts initially on the produce weren’t likely harmful.
This ties back to what we discussed with the Dirty Dozen— even the “dirtiest” produce didn't exceed safe pesticide limits, and buying organic doesn’t completely resolve the issue: Organic farming still uses pesticides, though of a different kind.
One additional note: Some pesticides are absorbed into the plant's tissues as it grows or are simply difficult to remove. These pesticides have been rigorously tested and don't pose a serious health risk. While you can’t remove every trace of pesticide, your produce likely starts with safe levels, and washing can reduce it further.
