Magnesium Chloride.

Choose magnesium chloride when environmental sensitivity is the primary constraint — properties adjacent to wetlands, fish-bearing streams, salt-sensitive landscape, or new concrete. Choose it when corrosion of vehicles, rebar, or building components is a recurring maintenance issue. Choose it when temperature is between –10 °C and –25 °C and straight rock salt is no longer effective but calcium chloride is unnecessary. Skip magnesium chloride for routine de-icing above –10 °C (rock salt is cheaper and equally effective) and for extreme cold below –25 °C (calcium chloride is faster and stays effective to –32 °C). Many municipalities standardise on magnesium chloride for road anti-icing because of the lower corrosion profile despite the 2–3x premium over rock salt.

Yes, in measurable ways. The chloride load per equivalent melt performance is roughly comparable across the three chloride de-icers, but the magnesium ion is less mobile in soil than the calcium ion, less likely to leach into shallow groundwater, and less aggressive on plant root systems. Magnesium chloride spray drift on adjacent landscape causes less visible turf damage than calcium chloride spray drift at the same application rate. Magnesium chloride is also less corrosive on submerged metal infrastructure (bridge decks, culvert pipes, stormwater fittings) and reduces the rate of chloride-induced rebar corrosion in concrete. None of these advantages eliminate environmental impact — chloride is chloride — but they reduce it noticeably vs. calcium chloride or treated rock salt.

Magnesium chloride flakes contain a hydrated crystal structure (typically MgCl2 · 6H2O). As meltwater evaporates, the crystal water releases and the magnesium chloride re-crystallises on the surface as a thin white film. This is cosmetic, not damaging, and washes off with rinsing. The residue is most visible on storefront glass, dark-coloured pavement, and entrance pads where evaporation happens unevenly. For those high-visibility applications, switch to calcium magnesium acetate (CMA) or potassium acetate — both evaporate completely and leave no residue. For routine parking-lot and driveway use the residue is not a concern, and the lower corrosion profile of magnesium chloride is usually worth the trade-off.

Yes — and it is a standard practice in commercial and municipal operations. Pre-blending magnesium chloride flakes into rock salt at 5–10 % by weight delivers most of the cold-temperature performance of straight magnesium chloride at a fraction of the cost. Liquid magnesium chloride brine pre-wetting (8–12 gallons per tonne of salt at the moment of discharge) is the more common method used by municipalities — it cuts application rates 20–35 % and extends effective melt temperature to –20 °C. Treated magnesium chloride blends are sold under brand names like Mag-Plus, ClearLane, and IceSlicer at retail. Most commercial contractors blend their own at the salt dome to control the ratio and the cost.

Bag, tote, and bulk quantities of magnesium chloride flakes and liquid ship through the same industrial chemical distributors as calcium chloride — Univar Solutions, Brenntag, ChemTrade, and Canadian regional players. We hold supply contracts and deliver to depots in every province with 48–96 hour lead time during the season. For retail bag quantities, Home Depot Canada, Canadian Tire, and specialty landscape-supply yards carry private-label and named-brand magnesium chloride products from October through March. Selection in retail is narrower than calcium chloride — most homeowners buy "ice melt" blends that contain magnesium chloride as a secondary ingredient rather than pure MgCl2 flakes.