What are the levels of heavy metals and microplastics found inside your favorite sea salt and Himalayan salt products? This was the question Mamavation community members asked us and we didn’t know the answer, so we sent 23 popular salt products off to an EPA-certified laboratory to find out. Do you want to know how high the levels of heavy metals & microplastics are in your favorite sea salt or Himalayan salt? You’ve trusted Mamavation to bring you topics like the safest butter without toxic PFAS packaging, the safest cookware sans PFAS and nanoparticles, & safest water purifiers to filter PFAS “forever chemicals,” now join us for the results of 23 salt products sent to the lab testing for metals aluminum & arsenic, & heavy metals cadmium, mercury, and lead & microplastics.
Disclosure: Scientific reviews were performed by (1) Terrence Collins, Teresa Heinz Professor of Green Chemistry & Director of the Institute for Green Sciences at Carnegie Mellon University & (2) Pete Myers, Chief Scientist at Environmental Health Sciences, Adjunct Professor of Chemistry at Carnegie Mellon University, and Co-Author of Our Stolen Future. This post was medically reviewed by Sondra Strand, RN, BSN, PHN. Donations were provided by Mamavation community members. Note that Mamavation has only “spot-checked” the industry and thus we cannot make predictions about brands and products that were not tested in our EPA-certified laboratory. Products and manufacturing aides can change without notice so buyer beware. This post contains affiliate links, with most to Amazon, which means Mamavation will receive a portion of those sales and we will use that to pay ourselves back for the testing. You can also give a tax-deductible donation to our consumer studies here through Environmental Health Sciences. Thank you!
Table of Contents
Aluminum, Arsenic, Cadmium & Lead Found in Salt Brands
According to the American Heart Association, the average American consumes about 3,400 milligrams per day of salt, whereas the dietary guidelines recommends we consume less than 2,300 milligrams (mg) of sodium daily. Americans are getting most of their sodium from processed foods, and therefore, if you are cooking and eating your meals from home in your own kitchen, you can greatly reduce those levels. It’s claimed that “eating less sodium can reduce your risk for high blood pressure, fluid retention, heart disease, stroke, kidney issues, osteoporosis and cancer.” This is why we highly recommend you cook most of your meals from scratch with ingredients that are minimally processed. But what about the quality of salt you are using? Some metals that are known or suspected toxicants & microplastics are already known to be inside salt but at what levels? This is the question we attempted to answer to help our audience lower their sodium intake while also lowering their intake of heavy metals and microplastics.
Mamavation sent 23 salt products off to an EPA-certified laboratory to test for aluminum, arsenic, and heavy metals cadmium, mercury & lead and microplastics. The good news is no salt product came back with the equivalent levels that would require a Prop. 65 warning based on serving size per day. In addition, no salt product had high enough microplastics that could be conclusively recognized through FTIR testing. The bad news was all salt products had detectable amounts of the subject metals present. Mamavation has done our best to share with you what our laboratory found so that if you are concerned about clearly toxic or potentially toxic metals inside your salt, you’ll be able to make an educated decision when shopping. Here’s what we found:
- The light metal, aluminum, was found in 78% of the salt products. 35% of salt products had over 100,000 ppb of aluminum.
- Arsenic was found in 100% of salt products. 74% of salt products had over 10 ppb of arsenic.
- Cadmium was found in 70% of salt products. 4% of salt products had over 4.1 ppb of cadmium.
- Mercury was NOT found in any salt products.
- Lead was found in 96% of salt products.
- Microplastics were so minute they could not be conclusively detected and recognized via Fourier Transformed Infrared (FTIR) Spectroscopic imaging for any sample.
Federal vs. California Prop. 65 “Safe Harbor” Levels For Heavy Metals like Lead & Arsenic
So what levels of lead, arsenic, mercury, & cadmium are concerning to public health officials? According to the Food & Drug Administration, the levels inside your food that you are allowed to be exposed to are as follows:
- Heavy metals as lead (as Pb), should not be in your food or supplements at more than 10 parts per million (ppm)
- Arsenic (as As), should not be in your food or supplement at more than 3 parts per million (ppm)
- Mercury (as Hg), should not be in your food or supplements at more than 1 part per million (ppm)
- Cadmium levels (as Cd) in bottled water should not exceed 0.005 parts per million (ppm)
When it comes to protecting consumers, California has far more stringent health protective levels, but instead of banning products, they require manufacturers to use label warnings instead. California’s Prop. 65 established “safe harbor levels” for most of the heavy metals we tested: arsenic, cadmium, lead, & mercury. Prop. 65 requires businesses to provide warnings to consumers living in California about significant exposures to chemicals that cause cancer, birth defects, or other reproductive harm. These chemicals can be in the products they purchase, in their homes or workplaces, or released into the environment. By requiring this information to be provided, it enables consumers in California to make informed decisions about their exposure to these chemicals.
Here are the No Significant Risk Levels (NSRL) and the Maximum Allowable Dose Levels (MADL) established by the State of California for the heavy metals we tested:
- Arsenic: 0.06 ug/day (inhalation), 10 ug/day (except inhalation)
- Cadmium: 0.05 ug/day (inhalation), 4.1 ug/day (oral)
- Lead: 0.5 ug/day level for reproductive toxicity, 15 ug/day (oral) for carcinogens
- Mercury: no established levels (and therefore no seafood would require a warning)
- Aluminum: no established levels (and therefore no salt products would require a warning)
The most difficult part to understand about Prop. 65 is it’s not about the actual test results. Defendents must prove that the average person would consume enough to the product in a 70 year period to cause cancer or reproductive harm. If that contaminate is “naturally occurring” like so many heavy metals are in the soil (especially in modern times from agricultural pesticides in the case of arsenic and lead and the myriad other uses of lead such as its now terminated use as a combustion promoter in gasoline), a company can avoid having to provide a warning label. Therefore, it’s complicated and difficult to understand unless you have good attorneys by your side to explain. But the bottomline is no salt product we tested would require a warning label under the California statute.
Aluminum in Food & Standards Set in Europe
Aluminum can come from natural sources as it makes up 8% of the earth’s mass. The Food & Drug Administration (FDA) considers aluminum used as an indirect additive in food “generally regarded as safe.” Thus aluminum compounds are used in many ways in American food production as preservatives, as color dyes, anti-caking agents, or for leavening breads without active yeast. It’s possible aluminum could be finding its way into salt in various levels as an anti-caking agent, which would help prevent it from clumping. However, not all of these products disclosed the use of aluminum as a food additive if they were using it.
The amount of aluminum from indirect food additives varies from person to person based on what you are eating, however, it’s assumed to be anywhere from 0 to 95 milligrams per day for Americans. The United States does not have any standards for aluminum in food that we could find. We could, however, find tolerable weekly intakes from the European Food Safety Authority (EFSA) & the World Health Organization (WHO) based on the precautionary principle.
- Based on the combined evidence from several studies, EFSA has recommended a tolerable weekly intake (TWI) of 1 mg aluminum/kg body weight/week. Thus using EFSA’s estimate, a person weighing 150 lbs. can tolerate up to the equivalent of 68 mg of aluminum per week.
- More recently, in 2011, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) reviewed scientific evidence which increased their confidence in the risk assessment, and thus WHO experts established an increased Provisional Tolerable Weekly Intake (PTWI) of 2 mg/kg body weight. This means, according to the WHO, someone who weighs 150 lbs. could safely 136 mg per week.
Because you are also getting aluminum inside other foods like baked goods with flour, beans, condiments, cereals, cheese sauces, root vegetables, & certain seafood, it may be possible, especially for people with bad kidneys, that you could be consuming more than a safe recommendation. In reflection of the Precautionary Principle, we’ve tested salt for aluminum for you as well to help you make those decisions yourself on where you would like your dietary aluminum to come from.
How Do Heavy Metals Find Themselves in Salt?
So how do heavy metals (aluminum, arsenic, cadmium, mercury & lead) find their way into salt? Officially, we are not certain brand by brand, but here are some theories based on how other food products are contaminated:
- Naturally Occurring: Heavy metals are naturally present in the soil in different concentrations based on the geology of the land. For instance, more cadmium is found in certain soils in South America and less in certain African soils. This may be why we consistently found higher heavy metals in Himalayan salts vs. most sea salts because Himalayan salt is dug out of the ground mostly in Pakistan, which is also known to have higher levels of Cadmium in the soil. However, it is to be remembered that Himalayan sea salt is thought to have been laid down in the Permian Epoch more than 250 million years ago so the metal content reflects that truly ancient environment.
- Legacy Pesticide Use: For many decades, heavy metals were added to pesticides as an adjuvants, or were key components of pesticide toxicity such as with lead arsenate used as a pesticide in orchards and can still be found in soils with a history of certain pesticide use. Thus, runoff from farm use could find its way into sea salt.
- Manufacturing Contamination: Heavy metals can be found in many manufacturing situations, for example, as equipment is used dust from abrasion can contaminate food and personal care products that way. When salt is processed, the manufacturing equipment itself could pose a contamination risk.
- Storage: In places where heavy metals are present in the soil, storing and drying certain salts outside can present a contamination risk. Dark chocolate is known to be contaminated this way.
- Air Pollution: Heavy metals can start as air pollution from manufacturing byproducts from polluted industrial areas and can find their way into other parts of the world through the wind and through bodies of water. For example, mercury originally found in coal is released into the air when coal is burned. Downwind it falls to the earth and is converted to methyl mercury, which moves up the food chain contaminating fish, including tuna. We were happy to see that mercury was non-detect for all samples of salt.
- Food Additives: Some food additives could be contaminated with heavy metals, or as in the case with aluminum, could itself be a food additive.
Investigation of Salts for Heavy Metals & Raw Data
To recap, Mamavation sent 23 salt products to an EPA-certified lab testing for aluminum, arsenic, cadmium, mercury & lead. 100% of salt products had detectable amounts of heavy metals and those levels and types of heavy metals varied. Here’s a couple of notes to consider before reading the raw data:
- The laboratory also looked for microplastics by using Fourier Transformed Infrared (FTIR) Spectroscopic imaging. Microplastics were found, but they were not in high enough levels for the test to conclusively recognize what type of microplastics they were.
- Parts per billion is ppb and parts per million is ppm.
- 1 ppm = 1,000 ppb
- MRL means Maximum Residue Levels which meant that the lab could detect some metals, but it was so low they could not measure the exact amount.
We divided the 23 salt products into 3 categories according to contamination levels. These levels reflect the overall levels of heavy metal contamination in each product but do not follow specific government recommendations.
(Update: 3 additional salt products were added to this investigation on 2/13/24 and are marked with a ** in the “not our favorite” category.)
Not Our Favorite Salt Products
These salt products represented the highest amounts of heavy metals according to our laboratory. Aluminum is reported in the ppm, while other heavy metals are reported in the ppb. In this category, you will find between 29 – 242 ppm of aluminum, 12.53 – 82.156 ppb arsenic, non-detect to 7.32 ppb cadmium, all mercury non-detect, and between 92.56 – 553.44 ppb of lead. (UPDATE: We added 3 additional salt products to this investigation from audience popularity and they are at the bottom of this category marked with a **. )
Not Our Favorite Salt Products
|Al in ppm
|As in ppb
|Cd in ppb
|Hg in ppb
|Pb in ppb
|Artisan Salt Company Ancient Ocean Himalayan Pink Salt
|Manischewitz Natural Kosher Salt
|McCormick Fine Ground Pink Himalayan Salt
|Redmonds Real Salt Ancient Fine Sea Salt
|San Francisco Salt Company Sherpa Pink Himalayan Salt
|Celtic Sea Salt Fine Ground
|Shaun Himalayan Salt
|The Spice Lab Himalayan Salt
|Trader Joes Himalayan Pink Salt Crystals
|Wellesley Farms Kosher Himalayan Pink Salt
|**Baja Gold Mineral Sea Salt Fine Grind
|**Colima Sea Salt
|**Crucial Four mMinerals (Polar White Sea Salt)
Better Salt Products
These salt products represent the middle of the road in terms of heavy metals according to our lab. Aluminum is reported in the ppm, while other heavy metals are reported in the ppb. This category has the following levels present: Between 2.154 – 80.468 ppm of aluminum, between 7.39 – 24.14 ppb of arsenic, between non-detect – 0.77 ppb of cadmium, no mercury, & between 45.63 – 84.45 ppb of lead.
|Al in ppm
|As in ppb
|Cd in ppb
|Hg in ppb
|Pb in ppb
|Frontier Co-Op Fine Grind Pink Himalayan Salt
|Seasonello Iodized Sea Salt
|Terrasoul Superfoods Himalayan Pink Salt
|Watkins Fine Himalayan Pink Salt
|Vera Salt Pure Natural Spring Salt Microplastic Free
Best Salt Products
These salt products had the lowest amounts of heavy metals. Aluminum is reported in the ppm, while other heavy metals are reported in the ppb. Here’s how low this category was: All aluminum was under 2 ppm, all arsenic was 15.27 ppb or less, all cadmium was 2.56 ppb or less, all Mercury was non-detect, and all lead was 14.99 or less. MRL means Maximum Residue Levels which meant that the lab could detect some metals, but it was so low they could not measure the exact amount.
Best Salt Products
|Al in ppm
|As in ppb
|Cd in ppb
|Hg in ppb
|Pb in ppb
|David's Kosher Salt
|Diamond Crystal Kosher Salt
|Hain Pure Foods Iodized Salt
|Jacobsen's Salt Company Kosher Sea Salt
|Maldon Sea Salt Flakes
|Morton Iodized Salt
|Saltverk Flaky Sea Salt
|Wellesley Farms Mediterranean Sea Salt