Which Salt Is Lowest In Heavy Metals? A Guide to Pure Salt Sourcing

November 1, 2025 •

5 min read

While trace minerals are often desired, a 2020 Australian study found wide variations of heavy metals like lead and aluminum in some pink salts, noting that higher levels were found in darker-colored varieties. For health-conscious consumers, knowing which salt is lowest in heavy metals is a critical step toward informed food choices.

Quick Summary

Examine how different salt types, from Himalayan to Celtic, are affected by heavy metals and microplastics. Discover the importance of sourcing, processing, and independent testing to choose a clean, low-contaminant salt brand for your home.

Key Points

Source Matters: The origin of the salt, whether from ancient seabeds, deep ocean, or surface waters, dictates its potential for heavy metal contamination.
Testing Is Key: The most reliable and transparent brands provide independent, third-party heavy metal test results, offering the highest confidence in a product's purity.
Color Can Deceive: The pink color in Himalayan salt comes from minerals, but studies show darker, flaked pink salts can also have higher levels of heavy metals like lead.
Deep Ocean is Promising: Salts from deep ocean waters (2,000+ ft), like Kona Sea Salt, are inherently low in heavy metals because the source is shielded from surface pollutants.
Don't Trust Marketing Alone: As seen with lawsuits involving Celtic Sea Salt, relying on marketing terms like "natural" without verifying independent testing can be risky.
Consider Ancient Sources: Salts from ancient seabeds, like Redmond Real Salt, are protected from modern environmental pollutants like microplastics.

Understanding Heavy Metals in Salt

Consumers increasingly seek out natural and unrefined food products, including salt. However, the term "natural" does not always equate to "pure". As contaminants like heavy metals and microplastics pollute our environment, they can find their way into our food sources, including both sea salt and rock salt. Heavy metals such as lead, cadmium, arsenic, and mercury can accumulate in the body over time, and while food safety regulations exist, many prefer to minimize their exposure.

Factors Influencing Salt Purity

Several factors determine the potential for heavy metal content in salt:

Source Location: The origin of the salt is perhaps the most critical factor. Salt sourced from pristine, protected environments, like deep ocean waters or ancient, untainted seabeds, is less likely to contain modern pollutants compared to salt harvested from surface ocean waters near industrialized areas.
Harvesting Method: The method of extraction also plays a significant role. Salt from solar evaporation of surface sea water can be vulnerable to microplastics and other contaminants floating in the water. In contrast, deep-brine and ancient seabed mining can be more protected, though the surrounding geology can introduce its own set of trace elements.
Processing and Refining: Refined table salt is often washed and heated to remove impurities, leaving nearly pure sodium chloride. This process can remove some contaminants, but some unrefined brands from exceptionally clean sources can achieve low heavy metal levels without harsh processing. Some modern methods, like ion-capture electrodialysis, can selectively remove toxic metals while retaining beneficial minerals.
Third-Party Testing: The most reliable measure of a salt's purity is independent, third-party lab testing. Transparent companies provide these test results, giving consumers peace of mind that their product is below established safety thresholds.

Common Salt Types and Heavy Metal Risks

Himalayan Pink Salt: Sourced from ancient seabed deposits, Himalayan salt contains trace minerals like iron oxide, which give it its characteristic color. However, a 2020 study showed wide variation in heavy metal content, including aluminum and lead, with some samples containing levels that raised public health concerns. The color's darkness and origin can be indicators of potential contaminant levels.
Celtic Sea Salt: Harvested from ocean water, Celtic sea salt is another popular unrefined option. Its sourcing makes it potentially susceptible to modern pollutants, including microplastics. A class-action lawsuit filed in 2025 also alleged high levels of lead and arsenic in some Celtic Sea Salt products, referencing the brand's own lab documents.
Deep Ocean Salt: Brands like Kona Sea Salt harvest from deep ocean waters, often at depths of over 2,000 feet, which are naturally protected from surface pollutants and industrial runoff. This deep sourcing results in naturally low levels of heavy metals and aluminum.
Ancient Seabed Salt: Mined from deposits of ancient evaporated seas, like Redmond "Real Salt" from Utah, this salt is considered low-risk for modern pollutants like microplastics. The mineral content depends on the specific geological makeup of the ancient seabed.
Refined Table Salt: This salt is heavily processed to strip away minerals and other impurities, resulting in a product that is almost pure sodium chloride. Some studies show that refined salt contains heavy metals below Codex limits, comparable to some rock salts, but the refining process can strip away beneficial trace minerals along with potential contaminants.

Comparison Table: Common Salt Purity


Salt Type	Sourcing Method	Heavy Metal Risk	Testing Transparency
Himalayan Pink Salt	Mined from ancient rock salt deposits.	Variable; depends heavily on brand and mine location. Some studies show concerning levels in certain samples.	Varies by brand. Some have test results available, while others do not disclose data.
Celtic Sea Salt	Solar evaporation of surface ocean water.	Potential for modern contaminants like lead, arsenic, and microplastics due to ocean pollution.	Varies by brand. Recent lawsuits highlight potential contamination risks despite some brands' marketing.
Deep Ocean Salt	Sourced from deep ocean water, protected from surface pollutants.	Generally very low. Companies like Kona Sea Salt cite deep-water sourcing for low heavy metal content.	High for reputable brands. Brands often highlight and share third-party test results for heavy metals and microplastics.
Ancient Seabed Salt	Mined from protected, ancient sea salt beds.	Low risk from modern pollutants, but can contain trace elements from the surrounding geology.	Varies by brand. Companies like Redmond "Real Salt" provide lab analysis results on their websites.
Refined Table Salt	Extracted from rock salt or brine, heavily processed.	Low from the intense processing, but stripped of beneficial minerals. Purity is high, but the refining process removes all trace elements.	Typically not marketed with heavy metal testing, but high purity from processing is implied.

How to Choose a Salt with Minimal Contaminants

Choosing a salt with the lowest heavy metal content requires more than just choosing a name brand. It's about performing due diligence as a consumer. Here's a quick guide:

Prioritize Third-Party Testing: The most reliable brands will provide access to independent lab test results for heavy metals and microplastics. Look for a Certificate of Analysis (COA) on the company's website.
Consider the Source: Brands sourcing from deep, pristine waters (e.g., Icelandic or Hawaiian) or protected ancient seabeds (e.g., Utah) offer cleaner alternatives. These sources are inherently better shielded from modern pollution.
Don't Judge by Color: Pink color is not an indicator of purity and can, in some cases, be associated with higher heavy metal concentrations, especially lead. High-purity salts are often white or clear.
Buy from Reputable Brands: Stick with established brands known for their transparency and commitment to product safety. Be wary of marketing claims that aren't backed by scientific evidence or test results.

Conclusion

While a definitive answer to "which salt is lowest in heavy metals?" is complex due to brand-to-brand variations, the clearest contenders are brands from pristine, protected sources that conduct and publish transparent third-party testing. Salts harvested from deep, unpolluted ocean waters or ancient, protected salt beds offer reliable purity with minimal risk of contamination. Ultimately, a consumer's best bet is to look beyond marketing claims and demand evidence of independent testing to ensure the cleanest, safest salt for their health.

Learn more about the science behind salt purity by reading this publication from the National Institutes of Health.

Frequently Asked Questions

Not necessarily. A 2020 study found significant variations in heavy metal content, including lead and aluminum, across different pink Himalayan salt samples. Brands vary, and independent testing is the only way to be sure of a specific product's purity.

Concerns have been raised due to its sourcing from surface ocean waters, which are exposed to pollution. A 2025 class-action lawsuit also alleged high levels of lead and arsenic in some Celtic Sea Salt products based on lab documents. Some brands may test clean, but consumers should check for third-party verification.

Reputable salt brands should publish their third-party lab test results, often called a Certificate of Analysis (COA), on their website. If a brand does not provide this information readily, it is best to be cautious.

Refined salt is heavily processed to remove impurities, resulting in almost pure sodium chloride. This process can remove heavy metals, but it also strips away beneficial trace minerals. Some studies have found comparable heavy metal levels in refined and rock salts, both within safety limits.

Trace levels of heavy metals are naturally occurring in the earth's crust and oceans, so almost all salts will contain some amount. The key is to find salt from a brand and source that ensures these levels are minimal and well below safe consumption thresholds.

Microscopic plastic particles, often from polluted oceans, can be found in sea salt due to the harvesting process. Some studies indicate that salt from traditional or geothermal harvesting can contain fewer microplastics compared to industrially harvested sea salts.

Look for a stated source (e.g., 'deep ocean water' or 'ancient seabed'), and check the brand's website for evidence of third-party heavy metal and microplastic testing. Claims of being 'natural' or 'mineral-rich' without verification should be treated with skepticism.

Salts from ancient, protected seabeds, like Redmond Real Salt, are generally shielded from modern ocean pollutants like microplastics. However, the purity is dependent on the specific geological makeup of that ancient source, so checking for testing is still recommended.

Athletes and health enthusiasts often seek salts rich in electrolytes like magnesium, potassium, and calcium, in addition to sodium. Brands like Kona Deep Ocean Sea Salt are mentioned for providing clean electrolytes for hydration and recovery.

Not necessarily. While refining can remove contaminants, it also strips away all beneficial trace minerals. Furthermore, some unrefined salts from pristine, protected sources can naturally have lower contaminant levels than some refined or less carefully sourced salts.