Both industrial and food grade salts are harvested from alpine regions.  Some suppliers will tell you that, “It’s food grade, but just without the certification.”  Although the altitude of the source does not necessarily guarantee the highest quality, it is usually better than polluted ocean waters, desalination wastes or dessert salt pans. If the salt water source in alpine regions is near any mining, agriculture or sewage outlets, or if magnesium salts are extracted via solution mining, they may contain unwanted contaminants and the harvested magnesium chloride flakes may not really be food grade. Solution-mining means they drill into the mountain to pump water into a hard buried layer of crystalised salts (bischoffite), and then pump out the solution to evaporation tanks. This requires extra cleansing and processing, which can also cause loss of extra trace minerals.

Food Grade is the Best

Food grade quality, representing 10-15% of magnesium chloride salts harvested in the world, is much rarer and is sold for a higher price than the more abundantly available industrial grade.  This rarer form of magnesium chloride is usually siphoned from open salt water lakes in pristine alpine regions and simply filtered and evaporated to form salt flakes.  It therefore retains a higher level of the naturally occurring trace elements. Food grade magnesium chloride (also called Nigari) is mainly used to make tofu by Asian food manufacturers, as well as for skin care products and horse feed supplements.  Pharmaceutical companies also buy it for further refining and use in pharmaceutical products.

Industrial grade magnesium chlorides are used for many applications including agricultural soil supplement, swimming pool salt, making magnesium metal, de-icing roads and cleaning dust from air of mining operations. For these purposes the industrial grade is fine. However, ‘Food Grade’ is ‘Food Supplement’, so be careful of the more commonly available industrial grade magnesium chloride hexahydrate flakes, which can have several toxic contaminants. If you are feeding magnesium chloride flakes to your horse or pets (or yourself) make sure they are certified food grade.  It should tell you on the package label.

If it’s not certified and you are not sure, ask the supplier for a trace mineral analysis with mercury and lead testing down to 10ppb by an independent laboratory.  Horses and pets won’t be able to notice the difference in taste if these metals are present, which means they could accumulate over time in the tissue cells.  If the retailer cannot supply the lab analysis, then at least ask them for the food grade certificate of analysis from their supplier-manufacturer.  Some magnesium chloride salts can also contain excess bromides and sulphates.  Whilst a small amount is tolerable from salts, an excess can cause gut irritations.

Of the 98% magnesium chloride hexahydrate flakes, the magnesium chloride compound is usually 46-48%, with about half of the flakes being crystalised water molecules, and total elemental magnesium content ranging from 12% to 16% of the flakes, depending on the source water and the processing methods. There is usually another 2% of mixed trace minerals remaining from the orinal salt water. The best quality will be food grade certified magnesium chloride flakes, naturally harvested, and with elemental magnesium content at about 15-16%.

To date Australian bulk salt processors do not offer food grade magnesium chloride for sale. 

In addition, don’t be fooled by ‘organic claims’ because when it comes to mineral extractions you could say that crude oil is also ‘organic’ (not grown with pesticides or chemical fertilizers). An inorganic mineral is an inorganic mineral and can have no other inference. A sea mineral salt is a complex of inorganic minerals.  There is no regulation in Australia regarding such claims (ie. calling an inorganic mineral ‘organic’) or the inference that the word ‘organic’ somehow makes it better. It’s a question of ‘buyer-beware’.