Yes, Potatoes Are on the 2025 Dirty Dozen List
For the 2025 Environmental Working Group (EWG) Shopper’s Guide to Pesticides in Produce, the potato has once again been designated as one of the 'Dirty Dozen'. The EWG’s annual report ranks 47 fruits and vegetables based on an analysis of more than 53,000 samples tested by the U.S. Department of Agriculture (USDA). Potatoes joined the list primarily due to the widespread use of a post-harvest chemical that has been banned in many other parts of the world.
The Chemical Driving the Concern
The primary chemical of concern regarding conventionally grown potatoes is chlorpropham (CIPC), a pesticide and plant growth regulator. USDA data revealed that an astonishing 90% of potato samples contained this sprout inhibitor, which is applied after harvest to prevent sprouting during storage and transit. The European Union banned chlorpropham in 2019 due to health concerns for both farmers and consumers. Because this chemical is applied so late in the process, its concentration remains notably high at the time of consumption.
EWG's Methodology and the Controversial List
Since its inception, the EWG's Dirty Dozen list has been a topic of debate. The organization's methodology has evolved over time, and for 2025, it included a toxicity assessment in addition to the frequency and concentration of pesticide residues. Critics, such as those at The Garden Professors blog, argue that the list is misleading and alarmist, ignoring official safety thresholds set by the Environmental Protection Agency (EPA). They point out that legal residue levels are not necessarily harmful. Conversely, the EWG maintains that 'legal does not mean safe' and that cumulative exposure to multiple pesticides over time is a valid concern. The debate highlights the different perspectives on what constitutes a safe level of chemical exposure in our food supply.
What About Sweet Potatoes?
It is important to differentiate between regular potatoes and sweet potatoes. While potatoes are on the Dirty Dozen, sweet potatoes are consistently featured on the 'Clean Fifteen,' the list of produce with the lowest pesticide residues. This difference is likely due to varying growing practices and the types of pests affecting each crop. The distinct lists underscore the nuance in making produce choices based on pesticide loads.
Comparison: Conventional vs. Organic Potatoes
| Feature | Conventional Potatoes | Organic Potatoes |
|---|---|---|
| Pesticide Residue | Higher residue levels detected, including chlorpropham. | No synthetic pesticides used; generally low-to-no residue. |
| Nutrient Content | May contain lower levels of certain nutrients compared to organic. | Higher levels of antioxidants, vitamin C, and minerals reported in some studies. |
| Cost | Typically less expensive due to higher yields and lower production costs. | Generally more expensive due to sustainable practices and lower yields. |
| Sustainability | Relies on synthetic pesticides and fertilizers, which can impact soil and water. | Focuses on soil health, biodiversity, and natural pest control. |
| Appearance | Often blemish-free and uniform in appearance. | May have minor imperfections but are free of chemical treatments. |
Practical Steps to Reduce Exposure
If you consume conventional potatoes and are concerned about pesticide exposure, you can take several effective measures at home. These methods will not eliminate all residues, especially systemic ones that have been absorbed by the plant, but they can significantly reduce surface-level contamination.
Best practices for washing potatoes:
- Wash and scrub thoroughly: Rinse the potato under cold, running water. Use a stiff vegetable brush to scrub the skin vigorously, dislodging dirt and potential surface pesticides.
- Consider a baking soda soak: For extra peace of mind, mix one teaspoon of baking soda per two cups of water and soak the potatoes for 12–15 minutes before scrubbing and rinsing. Studies have shown this can be more effective than plain water for removing surface chemicals.
- Peel the skin: Since much of the residue is on the skin, peeling the potato is a highly effective way to remove a large percentage of pesticides. While this means you will lose some nutrients found in the skin, it significantly lowers your exposure.
- Cook effectively: While cooking does not destroy all pesticide residues, some can be broken down by heat. For the most effective reduction, combine washing, peeling, and then cooking, as cooking alone is insufficient for heat-stable pesticides.
The Importance of Variety
Beyond potatoes, the EWG's 2025 Dirty Dozen list includes other high-residue crops:
- Spinach
- Strawberries
- Kale, collard & mustard greens
- Grapes
- Peaches
- Cherries
- Nectarines
- Pears
- Apples
- Blackberries
- Blueberries
Conversely, the Clean Fifteen lists produce with the lowest residues:
- Pineapples
- Sweet corn
- Avocados
- Papaya
- Onions
- Sweet peas (frozen)
- Asparagus
- Cabbage
- Watermelon
- Cauliflower
- Bananas
- Mangoes
- Carrots
- Mushrooms
- Kiwi
For consumers with budget constraints, prioritizing organic purchases for items on the Dirty Dozen list and opting for conventional options for the Clean Fifteen can be a strategic approach.
Conclusion: Making Informed Choices
Whether or not a food is on a list like the Dirty Dozen is a helpful data point for making informed purchasing decisions. For conventionally grown potatoes, the presence of specific chemical residues, like the EU-banned chlorpropham, is a documented concern that landed them on the 2025 list. While health experts emphasize the overall importance of eating fruits and vegetables regardless of how they are grown, those wishing to minimize pesticide exposure have clear options. Buying organic is the most direct solution, but proper washing, scrubbing, and peeling of conventional potatoes can also be very effective. By understanding the risks and available methods, you can make the best choices for your health and your family's. For further reading, consult the EWG's official guide to get the full picture on their analysis of pesticide residues.
