[Maven]

That's the thing, Salt, the impurities and their levels are unknown.

I see Dr. Quinn's post now. He made a list of what some of the impurities can be, I'm not sure of his source for it though. My own guess is this is only partial.

The impurities present in these chemicals can include acid-insoluble matter, alkali compounds, aluminum, ammonium, arsenic, barium, calcium, chloride, copper, fluoride, heavy metals, helium, insoluble matter, iodate, iron, lead, magnesium compounds, manganese, nitrate, nitrite, organic volatile impurities, phosphate, selenium, sodium, sulfate, and sulfur.