DEEP DIVE - SALTT Drink Mix and Heavy Metals

We tested SALTT Electrolyte Drink Mix Powder for heavy metals - all tested samples passed and comply with California Proposition 65. When properly mixed with water, SALTT also complies with the strict US FDA proposed "Action Levels" for Arsenic in drinking water of under 10 parts per billion.

Please note that, in addition to testing for heavy metals, we have also tested SALTT for PFAS/Teflon "forever chemicals," Glyphosate/Round-Up, Mycotoxins, BPA, and other contaminants. Full test results are available here.

This is the DEEP DIVE version of this blog post. It's going to get technical, we're going to go into concentrations, and there's going to be math. If you want the shorter version, check out this blog post instead.

The salt we use in SALTT is pretty cool stuff - it's quite rich in trace minerals, especially magnesium, to the extent that SALTT has more magnesium than most other electrolytes and we're not even adding magnesium! One concern that we've been asked is: do those trace minerals include heavy metals like lead or arsenic? To answer this, we have done a number of extremely sensitive tests that can detect as little as 1 part per billion (0.0000001%). 

Something that is pretty important when you are talking about heavy metal exposure (not the music kind) is that there are 2 very different measurements:

1. Total Amount - typically measured in micro grams (μg) or 1/1,000,000 of a gram.
2. Concentration - this is measured in parts per million or parts per billion. 1 ppm is 1000 ppb; and 100 ppb is 0.1 ppm

Just for fun, here's what 1 ppb equates to: a US Nickel happens to weigh exactly 5 grams. If you had 5 MILLION kilograms (just over 11 million pounds or exactly the water weight in two Olympic-size swimming pools) that 5g nickel would be 1 part per billion. A 5g us Nickle also weighs 5 million micro grams.

If you have the "serving size" of something, you can convert back and forth between amount and concentration but it is very important that you don't mix up micrograms and ppb. Some of the health or legal standards are for one and some are for the other. Similarly, the US FDA "Proposed Action Level" for Arsenic CONCENTRATION in drinking water requires that the concentration account for... water. You can't test a dry powder mix that is meant to be diluted in water and then apply a proposed standard for water to the dry powder, that's silly.

Because the tests we have done are so sensitive, and we're testing the concentrated dry salt, the results show small levels of lead and arsenic in all of the samples tested. None of the samples tested had any detectible level of mercury and only the Cocoa Loco (chocolate) had any measured level of cadmium. The average concentration of lead in the dry SALTT powder is 23 ppb. For context, in this 2021 study, it shows the level of lead in raisins was 47 ppb (see table 6), and celery to be 27 ppb (see table 7). It should again be noted that the concentration levels we found for SALTT are the dry powder only - when mixed with 1 liter of water (around 32 oz) the concentration of Lead drops to 0.023 ppb and the concentration for Arsenic drops to a maximum of 3.39 ppb (the standard for drinking water is to be under 10.0 ppb).

This is important, we want to make sure it's fully understood. Let's say that you mix 4g of salt and 4 micro grams of arsenic into 996g of water. Even when it's in the water, you have the same 4g of salt and 4 micro grams of arsenic, but the concentration in water is different: exactly 4,000,000 parts per billion for the salt and 4 ppb for the arsenic). If you take that mixture and dry it out to a powder, the concentration of arsenic would suddenly jump to 1000 parts per billion. The same 4 micro grams can represent 4 ppb or 1000 ppb. You can't test a dry powder mix that is meant to be diluted in water and then apply a proposed standard for water quality to the dry powder

Concentration and Mixing Are Important

Let's take just a bit to look again at CONCENTRATION levels in our quality tests. The US FDA has proposed an "Action Level" for lead and arsenic concentration in drinking water, baby food, apple juice, and a few other foods; mostly in regards to developing infants and children. Infant Rice Cereal is set to 100 ppb of arsenic, and bottled water is limited to 10 ppb of arsenic, matching the U.S. Environmental Protection Agency (EPA) drinking water standard.

Because these are concentration levels, and we are talking about a dry electrolyte drink mix, the concentration figure is extremely dependent on if the tested substance has been diluted in water or not. It's also worth noting that this assumes the WATER is not adding arsenic or lead.

The water at our office contains 1.2 ppb of lead (average) and ranges from 0 to 4.4 ppb of arsenic with a "Total Dissolved Solids" of 708 ppm. If you were to dry out 6.53 liters of that water to replicate the 4.62g serving of Clean Slate SALTT, the resulting dry powder would have 1695 ppb of lead and 6215 ppb of arsenic (which is 7.83 μg of lead and 28.73 μg of arsenic - 15x and 3x higher than the Prop 65 limits, so I would not recommend consuming this).

When properly diluted in water, SALTT Electrolyte Drink Mix conforms to the US FDA Proposed "Action Levels" for Arsenic concentration in drinking water. If you choose to ignore common sense and look at the dry powder alone, it most definitely contains extremely high levels of many minerals especially sodium (147,336,377 ppb), potassium (62,300,000 ppb) and magnesium (23,359,944 ppb), plus other trace minerals including copper (150 ppb), manganese (188 ppb), arsenic (663 ppb) and lead (14 ppb). 

Ironically, if you test dry Clean Slate (4.62g), which has all of the minerals but none of the flavoring, sweetener, or the malic acid to add tartness of the flavored SALTT (6.57g), this smaller mass means all of the minerals represent a higher concentration (that's how ratios and percentages work!) so the clean slate is guaranteed to have the highest dry ppb of our flavors (663 vs the 410 of our Cherry Chill). 

Total Amount and Concentration in 1 liter of water. 

If you prefer to use 500ml of water instead of 1 liter, you would double the PPB. 1 liter of water is roughly 1000g. The actual formula for calculating parts per billion is:

[total amount μg] / ([mass dry powder] + [mass water]) * 1000 = parts per billion

Hypothetically, if a batch of Clean Slate happened to test nearly 50% higher than any of the other tests we have ever done, with a super high concentration of 920.3 ppb for arsenic in the dry powder. When properly diluted in 1 liter of drinking water, the actual concentration of arsenic would be reduced to 4.23 parts per billion, which is lower than the 10 parts per billion in the proposed "Action Level". Specifically it would be 42.3%. 

HOWEVER: If you apply a drinking water standard to a dry powder and assume the 920.3 ppb is at all relevant - you might make a simple math error and say 920.3 is 92x or 9203% the FDA Proposed "Action Level" of 10. Please don't make that simple math error!

The Test Results

These figures have been converted from concentration in the dry powder into total amount so that you can compare them to the proposition 65 maximum target. The raw concentration figures for the dry powder are in the linked test results.

The original lab reports for each flavor are linked above. As noted previously - all of the samples tested are below the California Proposition 65 "OEHHA Safe Harbor Levels" listed below and consequently do not need to have a Prop 65 warning.

• Arsenic: 10 (μg/day) No Significant Risk Levels (NSRL) for cancer-causing chemicals. Defined as the daily dose level that causes no more than one excess case of cancer in 100,000 individuals exposed over a 70-year lifetime.
• Cadmium: 4.1 (μg/day) Maximum Allowable Dose Levels (MADL) for chemicals causing reproductive toxicity
• Mercury: 0.3 (μg/day) Maximum Allowable Dose Levels (MADL) for chemicals causing reproductive toxicity
• Lead: 15 (μg/day) No Significant Risk Levels (NSRL) for cancer-causing chemicals
• Lead: 0.5 (μg/day) Maximum Allowable Dose Levels (MADL) for chemicals causing reproductive toxicity. This is 1/1000 the "no observable effect level" of 500 μg to "provide an ample margin of safety"

Where we get our SALT... T

One interesting question becomes: why are the levels of heavy metals in SALTT so low? The water quality report for our office shows a maximum concentration of 1.2 ppb lead, 4.4 ppb arsenic, and 99 ppb sodium in the local drinking water, shouldn't a concentrated salt have WAY higher numbers than our tests on SALTT?

The salt that we are using comes from the North arm of the Great Salt Lake which has some unique properties, even for the Great Salt Lake. The causeway that splits the lake makes the North section have a far higher concentration of minerals, it's also what amounts to a giant settling pond that allows any heavy elements to sink (which is why the potential for the lake drying and exposing the lake bottom is a very bad thing). Because of the way the brine is harvested, we're not getting a high concentration of heavier elements, only the lighter ones. 

The high concentration of salt in the North section of the lake is actually a problem for the lake and is one of the reasons our salt is harvested from that area instead of the much closer South area. The amount of salt we are removing out of the North section can only be a good thing.