- All methods of washing fruits and vegetables reduced pesticide residues, but effectiveness varied widely and depends on the pesticide, produce and method.
- Soaking produce in a solution of baking soda or vinegar solution was more effective than soaking or rinsing in water, on average.
- EWG scientists recommend improvements to how pesticides are monitored in food and in people to further reduce exposure.
WASHINGTON – Affordable, simple household practices can reduce pesticide levels on fruits and vegetables and help consumers lower their daily dietary exposure to potentially harmful farm chemicals, a new peer-reviewed study by Environmental Working Group scientists finds.
The study builds on EWG’s pesticide consumer guidance in the annual Shopper’s Guide to Pesticides in Produce™ and its comprehensive research on pesticides exposures.
“Fruits and vegetables are essential to a healthy diet, but they can also increase exposure to pesticides,” said Dayna de Montagnac, M.P.H., associate scientist at EWG and lead author of the study.
“Our findings reinforce the effectiveness of safe and accessible ways to reduce pesticide exposure while highlighting necessary improvements in research and monitoring to further reduce it,” she said.
Pesticide residues on produce
The review, published recently in the journal Frontiers in Environmental Health, analyzed data from 47 peer-reviewed studies of 23 produce items and 79 pesticides. The findings point to safe and effective methods consumers can use at home to reduce pesticide residues and provide a starting point for more research and monitoring in this area of study.
Last year, EWG published peer-reviewed research showing how the consumption of fruits and vegetables with higher pesticide residues is linked to measurable levels of pesticides in urine. Other recent publications have investigated the growing problem of PFAS pesticides, chlormequat and glyphosate.
Studies of the general population show exposure to pesticides is linked to cancer, reproductive harm, hormone disruption and neurotoxicity in children.
Residues of these chemicals are often detected on produce and frequently appear in mixtures on every type of produce, except potatoes, with an average of four or more pesticides detected on individual samples, according to EWG’s recent analysis of Department of Agriculture pesticide testing data.
Key findings
EWG scientists reviewed data that recorded pesticide concentrations of fruits and vegetables before and after rinsing or soaking them with water, baking soda or vinegar. Experiments where scientists rinsed their produce for more than two minutes were excluded to better reflect how people likely wash their produce at home.
Among the key findings:
- All washing methods reduced pesticide residues, but effectiveness varied widely.
- Rinsing with water showed modest reductions, with a median of 30.2%, although reductions ranged from 0% to 94%.
- Soaking in plain water performed slightly better than rinsing, with reductions from 0.6% to over 99% and a median of 33.7%.
- Baking soda soaking substantially improved removal, achieving reductions from 0.2% to over 99%, with a median of 50.9%.
- Vinegar, or acetic acid, soaking was the most effective method overall, with reductions ranging from 8.6% to over 99% and a median of 54.2%.
- Baking soda and vinegar treatments outperformed plain water by more than 15 percentage points in median pesticide reduction across studies, likely because of how certain pesticides break down in alkaline or acidic environments.
- Real-world effectiveness may be lower than what EWG’s study showed, since many studies used higher concentrations of baking soda or vinegar than a typical household would.
- Key factors influencing pesticide removal included the chemical properties of the pesticide, the washing method used, and the type and surface characteristics of the produce.
These findings confirm the role washing produce can provide in moderately lowering pesticide levels.
Where more work is needed
The study’s authors recommend that government agencies make it a priority to monitor stubborn pesticides, those that remain on produce even after household washing.
They also suggest expanding biomonitoring of fruits and vegetables to include pesticides frequently detected in the U.S. food supply.
Future research should explore what proportion of pesticide residues remain within specific produce items and to what extent these residues increase exposure.
The authors also suggest study designs that are more realistic, such as testing for the effect of rinsing for just a few seconds as a baseline. Further experiments could then show how adding baking soda or vinegar, with incremental increases in concentrations and washing times, can compare to the baseline method.
What consumers can do
EWG recommends regularly washing and eating plenty of fruit and vegetables.
Washing produce in any way will always be better than no washing in reducing exposure to pesticide residues. The USDA’s Pesticide Residue Program rinses produce samples with cold water for 15 to 20 seconds before testing produce, reflecting the assumption that consumers do basic washing at home.
A quick rinse or soak works in a pinch. When feasible, the addition of baking soda or vinegar to soaking solutions can further reduce residues. Refer to EWG’s guide on washing produce for more guidance.
When possible, EWG recommends prioritizing organic produce for the most pesticide-heavy produce listed in its Shopper’s Guide. The guide features the Dirty Dozen™ list of the produce with the highest pesticide residues detected and the Clean Fifteen™ list of items with the lowest residues.
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The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action.
