Foods with High Perchlorate Levels and How to Reduce Exposure

November 4, 2025 •

4 min read

According to a 2024 Consumer Reports study, perchlorate was detected in two-thirds of common food samples tested, with some of the highest levels found in baby food and certain fresh produce. These findings highlight a widespread issue, prompting many to question exactly what foods are high in perchlorate and how to address this exposure risk.

Quick Summary

This article details common food sources of perchlorate contamination, including leafy greens, dairy, and processed foods. It explains how perchlorate enters the food chain and offers practical strategies for reducing dietary exposure to this chemical.

Key Points

Leafy greens often contain high perchlorate levels: Due to accumulation in leaves from contaminated soil and water, items like spinach, arugula, and collard greens frequently show elevated amounts.
Baby food and processed foods are potential sources: Contamination can occur during processing and through migration from anti-static plastic packaging, affecting products like baby cereals and boxed mac and cheese.
Perchlorate impairs thyroid function: By interfering with iodine absorption, perchlorate can disrupt the thyroid gland, which is especially concerning for sensitive groups like pregnant women and infants.
Varied diet can help reduce risk: Eating a wide variety of foods prevents overexposure from a single, heavily contaminated source and is the recommended approach by health experts.
Contaminated water is a key factor: Perchlorate can enter the food supply through contaminated irrigation water, and filtering drinking water with a reverse-osmosis system can be a key mitigation strategy.
Iodine intake can offset effects: Maintaining adequate iodine levels can help counteract the thyroid-disrupting effects of perchlorate.

What is Perchlorate and Why is it in Our Food?

Perchlorate is a chemical compound that can disrupt the function of the thyroid gland by interfering with its ability to absorb iodine, a nutrient essential for producing thyroid hormones. While it occurs naturally in some environments, much of the contamination in our food supply is a result of industrial activities. Perchlorate is a key ingredient in rocket fuel, explosives, and fireworks. This chemical can enter the environment through manufacturing waste, military activities, and the use of certain fertilizers.

Once in the soil or water, perchlorate is easily absorbed by plants, where it accumulates, especially in the leaves. It can also contaminate food during processing via chlorinated water or from specific types of plastic packaging, which use perchlorate as an anti-static agent. This widespread presence means that even people who eat healthy diets that are rich in fruits and vegetables can still be exposed.

Specific Foods with High Perchlorate Content

Research by organizations such as the U.S. FDA, European Food Safety Authority (EFSA), and Consumer Reports has identified several food categories with elevated levels of perchlorate contamination.

Leafy Green Vegetables

Because perchlorate accumulates in plant leaves, fresh leafy greens often show high levels, especially if they are grown with contaminated water.

Spinach: Multiple studies have found high average concentrations of perchlorate in spinach.
Arugula: In a Canadian Food Inspection Agency (CFIA) survey, one sample of arugula was found to have a very high perchlorate level.
Collard Greens: The FDA identified collard greens as a food with some of the highest perchlorate levels.
Lettuce and Kale: These are also frequently cited as high-risk leafy vegetables.

Dairy Products

Dairy products can become contaminated when cows consume feed or water containing perchlorate.

Milk, Sour Cream, and Ice Cream: The FDA has previously detected perchlorate in milk products.
Infant Formula: This is a particularly vulnerable category, as infants have a greater sensitivity to thyroid hormone disruption. Studies have shown that infant formula can be a source of significant exposure.

Processed and Packaged Foods

Perchlorate can migrate into food from anti-static plastic packaging, especially with dry foods.

Baby Cereals: Tests have shown high levels of perchlorate in baby rice and multigrain cereals, potentially linked to packaging.
Boxed Macaroni and Cheese: Consumer Reports specifically noted high levels in this common children's food.
Cured Meats: Items like bologna and salami have shown high, though varying, levels of perchlorate in past FDA studies.

Other Food Sources

Fruits and Vegetables (in general): A wide variety of fruits and vegetables are susceptible to contamination, including cucumbers, carrots, and tomatoes.
Tea and Herbs: Perchlorate can accumulate in tea leaves, leading to residues in tea beverages. Herbal teas are also a source of concern.
Drinking Water: While food is the primary source of perchlorate for most people, contaminated drinking water can also contribute, especially in areas near industrial sites.

How to Reduce Perchlorate Exposure

Completely eliminating perchlorate is difficult given its widespread nature, but several strategies can help minimize exposure.

Tips for Minimizing Dietary Exposure

Prioritize Variety: Eating a wide variety of different foods reduces reliance on a single source and lowers the chance of accumulating concerning levels from one specific contaminated item. The health benefits of eating fruits and vegetables still outweigh the risks for most people.
Wash Produce Thoroughly: While perchlorate is a systemic contaminant, washing produce can still help remove any surface contamination, including from rinse water.
Choose High-Iodine Foods: Increasing iodine intake can help offset the thyroid-disrupting effects of perchlorate. Good sources include iodized salt, seafood, and dairy products. Discuss this with a healthcare provider, especially if you have an existing thyroid condition.
Consider Reverse-Osmosis Filtration: If you live in an area with known water contamination, a reverse-osmosis water filter can effectively remove perchlorate from your drinking water.
Be Mindful of Processed Foods: Limit packaged and processed items, especially those that come in plastic containers that may be contributing to contamination.

Comparison of Perchlorate Sources


Source Category	Primary Contamination Route	Examples	Mitigation Strategy
Fresh Produce	Irrigation with contaminated water, absorption from soil.	Leafy greens (spinach, arugula, collards), root vegetables, cucumbers.	Wash thoroughly; consume a varied diet to avoid overexposure from one source.
Dairy & Milk Products	Contaminated animal feed and water.	Milk, sour cream, infant formula.	Eat a varied diet; ensure adequate iodine intake.
Packaged & Processed	Migration from anti-static plastic packaging.	Baby rice cereals, boxed mac and cheese.	Reduce consumption of highly processed and packaged foods.
Drinking Water	Industrial waste, military activity, agricultural fertilizers, chlorine bleach.	Tap water, water used in food production.	Use a reverse-osmosis filter if tap water is contaminated; use fresh bleach.
Tea & Herbs	Accumulation in plant leaves.	Tea leaves, herbal teas.	Choose different beverages; opt for variety.

Conclusion

Perchlorate contamination is a complex issue, with sources ranging from industrial waste and agricultural fertilizers to food packaging. While a wide array of foods can be affected, some of the highest levels have been consistently found in leafy green vegetables, certain dairy products, and packaged foods, including those specifically for infants and children. The health risks are most significant for sensitive populations like pregnant women and young children, as perchlorate can disrupt crucial thyroid function. However, for the average adult, health authorities emphasize that the benefits of a varied, healthy diet rich in fruits and vegetables outweigh the potential risks of moderate perchlorate exposure. By being aware of potential sources, consuming a diverse diet, ensuring adequate iodine intake, and taking steps to address contaminated water supplies, consumers can make informed choices to help minimize their overall exposure to this chemical. National Institutes of Health on Perchlorate Exposure

Frequently Asked Questions

Perchlorate enters the food supply primarily through contaminated water used for irrigation, which plants, especially leafy greens, absorb from the soil. It can also migrate into food from certain types of plastic packaging or from the use of chlorinated water in food processing.

Perchlorate is a highly soluble chemical that is absorbed by plant roots. As water evaporates from the leaves during transpiration, the perchlorate is left behind and accumulates in the leaf tissue, leading to higher concentrations in leafy greens.

No, perchlorate contamination has been known for decades. The extent of the issue became clearer with improved testing methods in the late 1990s, revealing widespread contamination from industrial sources.

No, health authorities advise against this. The health benefits of eating a varied diet rich in fruits and vegetables generally outweigh the risks from perchlorate exposure for the average person. The key is to eat a variety of foods rather than relying too heavily on one source.

While washing can remove surface contaminants, it cannot remove perchlorate that has been absorbed into the plant's tissue from the soil or water. The best strategy is to consume a diverse diet.

Yes, infants and young children are considered more susceptible to perchlorate's effects because thyroid hormones are critical for brain and nervous system development during this life stage. Their lower body weight also makes a single serving of a contaminated food a more concentrated dose.

The main health concern is that perchlorate interferes with the thyroid's ability to absorb iodine, which is needed to produce thyroid hormones. High or repeated exposure can potentially disrupt thyroid function and cause hypothyroidism.