Questions around heavy metals in food, supplements and electrolyte products have received increasing attention — and understandably so.
When you use a product regularly, you want to know what's in it, where its ingredients come from and what testing has been done to ensure the product meets appropriate safety standards.
SALTT recently published the results of extensive testing of its Electrolyte Drink Mix, including testing for heavy metals such as arsenic, lead, cadmium and mercury.
The results are reassuring, but there's also an important part of the story that can easily be misunderstood: the difference between the concentration measured in a dry electrolyte powder and the concentration present once that product is mixed with water as intended.
Here's what SALTT's testing found — and what those numbers actually mean.
FIRST, WHY CAN HEAVY METALS BE PRESENT AT ALL?
Heavy metals aren't necessarily something that has been deliberately "added" to a product.
Elements such as arsenic, lead, cadmium and mercury occur naturally in the environment and can be found at extremely small levels in soil, water and many everyday foods.
SALTT is particularly interesting because its salt is naturally rich in trace minerals. The salt used in SALTT comes from the North Arm of Utah's Great Salt Lake, providing naturally occurring minerals including magnesium.
Because of this natural mineral profile, SALTT wanted to understand whether those trace minerals also included measurable amounts of heavy metals.
The answer required extremely sensitive laboratory testing capable of detecting concentrations as low as one part per billion (ppb).
WHAT DID THE TESTING FIND?
Testing detected very small amounts of arsenic and lead in the SALTT samples tested.
Importantly:
Mercury was not detected in any of the tested samples.
Cadmium was not detected in most samples, with a measurable amount identified in Cocoa Loco.
The tested products remained below the California Proposition 65 thresholds referenced by SALTT and therefore did not require a Proposition 65 heavy-metal warning based on those results.
SALTT has also undertaken testing for other contaminants, including PFAS or "forever chemicals", glyphosate, mycotoxins and BPA.
But understanding the heavy-metal results requires understanding one particularly important concept.
CONCENTRATION AND TOTAL AMOUNT AREN'T THE SAME THING
This is where discussions about heavy metals can become confusing.
There are two different ways of talking about what's present in a product:
Total amount — usually measured in micrograms (μg).
Concentration — usually expressed as parts per million (ppm) or parts per billion
(ppb).
They're related, but they don't mean the same thing.
And when we're talking about a concentrated electrolyte powder designed specifically to be mixed into water, that distinction becomes particularly important.
WHY TESTING DRY POWDER CAN CREATE MISLEADING NUMBERS
Imagine measuring something in a concentrated powder before adding any water.
Because there's very little total mass, naturally occurring trace elements can appear relatively high when expressed as parts per billion.
Now take exactly the same powder — containing exactly the same amount of those trace elements — and mix it into a litre of water.
Nothing has disappeared.
The total amount hasn't changed.
But the concentration has changed dramatically because it is now dispersed throughout a much greater volume.
This distinction is particularly important when comparing an electrolyte powder with standards designed specifically for drinking water.
A drinking-water concentration standard can't simply be applied to a concentrated dry powder without accounting for the water the product is intended to be mixed with.
SO WHAT HAPPENS WHEN SALTT IS ACTUALLY MIXED WITH WATER?
This is where the testing becomes particularly useful.
SALTT calculated the concentration of arsenic and lead after a serving was mixed into one litre of water.
Across the flavours reported in SALTT's analysis, arsenic concentrations in the prepared drink ranged from approximately:
2.7 to 3.4 parts per billion.
For comparison, the US drinking-water benchmark discussed in SALTT's analysis is:
10 parts per billion for arsenic.
The lead concentrations reported for SALTT prepared in one litre of water were approximately:
0.1 to 0.2 parts per billion.
It's important to remember that these calculations assume the water being used to prepare SALTT isn't itself contributing additional arsenic or lead.
WHAT ABOUT THE TOTAL AMOUNT IN EACH SERVING?
SALTT also converted the laboratory results from concentrations in the dry powder into the total amount present in a serving.
Among the products tested, the reported arsenic amounts were approximately 2.69–3.42 micrograms per serving.
Reported lead amounts were approximately 0.065–0.210 micrograms per serving.
These results were below the California Proposition 65 thresholds referenced in SALTT's analysis.
This is one of the reasons context matters when interpreting laboratory testing.
A large number expressed in "parts per billion" can sound alarming on its own. But without knowing the serving size, total amount and whether the product is concentrated or diluted, that number doesn't tell the complete story.
