The Science

Purest Electrolyte Sea Salt Test Results

By Purest Electrolyte

Our sourcing in Guérande France

We take our sourcing very seriously. We traveled to Guérande, France, to meet our salt farmers, see how our sea salt is processed, watch testing and talk with them about how the salt is tested.

Our sea salt from France was tested for lead, arsenic, cadmium and mercury. All four results were below the limits listed on its certificate of analysis. The results report trace amounts, and we are sharing the exact numbers and full certificate below.

Pam Sweeney, founder of Purest Electrolyte, with one of our salt farmers beside harvested sea salt in Guérande, France
Pam, the founder, with one of our salt farmers in France.
Pam Sweeney talking with one of our salt farmers beside the salt ponds in Guérande, France
Meeting our salt farmer at the salt marshes in Guérande, France.

Our French sea salt contains sodium, magnesium, potassium and calcium. These minerals play roles in fluid balance, nerve signals and muscle function. Sea salt is mostly sodium chloride. The full mineral analysis appears in the certificate below.

Heavy metal results

These results describe the sea salt ingredient listed in the certificate. The certificate is dated 4/8/2024 and marked valid through 1/5/2025.

Sea salt heavy metal test results
MetalReported result in sea saltSpecification printed on the certificate
Lead0.57 ppmLess than 1.00 ppm
Arsenic0.06 ppmLess than 0.50 ppm
CadmiumLess than 0.01 ppmLess than 0.50 ppm
MercuryLess than 0.005 ppmLess than 0.10 ppm

The reported amounts of lead, arsenic, cadmium and mercury are all below the limits shown on this certificate.

Why sea salt is tested

These elements can occur naturally in soil and water. Human activity can also add to their levels. They can enter food ingredients from the environment. The FDA explains how these metals can get into food.

What the numbers mean

PPM means parts per million. For a solid ingredient, 1 ppm equals 1 microgram per gram. The lead result of 0.57 ppm means 0.57 micrograms of lead per gram of the salt described in this certificate.

Less than 0.01 ppm means the amount was reported as below that level. It does not mean zero.

Common questions

Did the salt meet the listed heavy metal limits

Yes. All four reported heavy metal results are below the limits printed on this certificate.

How small are the reported amounts

The test found very small amounts of lead and arsenic in the sea salt. The numbers in the table show how much was found. Cadmium and mercury were reported as less than the amounts shown. All four reported amounts were below one part per million by weight.

For scale, 0.57 ppm lead equals 0.000057% of the salt’s weight. The arsenic result of 0.06 ppm equals 0.000006%. These are very small fractions by weight. Trace amounts means small amounts are present or may be present, rather than a result of zero.

Trace metals in everyday foods

Trace metals can be found in everyday foods, including rice, spinach, other vegetables and seafood.

Sources

French grey sea salt certificate of analysis, lot L0840215, dated 4/8/2024 and marked valid through 1/5/2025. The full analysis summary is included below.

FDA Environmental Contaminants in Food

FDA Cadmium in Food and Foodwares

FDA Arsenic in Food

FDA food testing averages from 2018 to 2020

FDA mercury measurements in seafood

NIH Magnesium Fact Sheet

NIH Potassium Fact Sheet

NIH Calcium Fact Sheet

Purest sea salt certificate

Certificate of analysis summary

Origin: France. Ingredient: Sea salt. Lot code: L0840215.

Source certificate date: 4/8/2024. Source valid through: 1/5/2025.

Date of manufacture: 8/19/2024. Invoice date: 8/23/2024.

Chemical analysis

Full sea salt chemical analysis
ParameterResultSpecification
Chloride (Cl)60.20 %NS**
Sodium (Na)36.30 %NS**
Sodium Chloride (NaCl)99.23 %> 97.0 %
Calcium (Ca)0.20 %NS**
Iodine (I)< 0.00005 %NS**
Magnesium (Mg)0.53 %NS**
Potassium (K)0.14 %NS**
Insolubles0.11 %NS**
Moisture1.54 %NS**
Arsenic (As)0.06 ppm< 0.50 ppm
Cadmium (Cd)< 0.01 ppm< 0.50 ppm
Copper (Cu)< 0.08 ppm< 2.00 ppm
Chromium (Cr)0.22 ppm< 0.50 ppm
Lead (Pb)0.57 ppm< 1.00 ppm
Mercury (Hg)< 0.005 ppm< 0.10 ppm

NS means no specification under CODEX STAN 150:1985. Specifications are based on Codex Stan 150:1985. Values may not total 100% because of rounding.

Particle size

Sea salt particle size
GrainLow averageHigh average
Velvet0.0 mm0.2 mm
Fine0.3 mm1.0 mm
Tamisé*1.0 mm3.0 mm
Brut2.0 mm5.0 mm

Tamisé is the grade marked on the source certificate.

Testing notes

Chemical analysis and microbial testing are performed once per year. The supplier states that testing of a specific lot requires additional time and cost.

Summary of the supplier’s sea salt certificate. Results and dates are reproduced as reported.

Choosing a clean sea salt electrolyte

If you are looking for a sea salt electrolyte that is low in heavy metals, compare the actual test numbers and what was tested. Look at the ingredient list too. Explore our ingredients and sourcing, and read more about Purest.