Magnesium Chloride for Snow Removal

Magnesium Chloride for Snow Removal. Magnesium chloride (MgC12) is an increasingly popular alternative to sodium chloride (NaCl), the inexpensive standard for ice and snow melting for most municipal road clearing teams. Magnesium chloride is less corrosive and aggressive than rock salt and less toxic to plant and animal life and surrounding waterways. It functions as an anti-freeze by lowering the temperature of water and preventing it from bonding to the road, and is available in flake or pellet form for home use.

About Magnesium Chloride

Magnesium chloride attracts moisture from the atmosphere and creates heat through a chemical reaction, preventing snow and ice from sticking to the ground. It can also effectively be used to remove a thin layer of snow or ice that has already hit the ground. The Arizona Department of Transportation praises magnesium chloride as less toxic than baking soda or salt because it is rapidly diluted. When applied at the proper rate, it produces less negative effects than sodium chloride or calcium chloride on wildlife, water or soil surrounding the treated area. This is not to suggest that it has no negative effects on plant or wildlife. According to a March 2004 article in “High Country News,” Summit County in Colorado banned the use of magnesium chloride after routine use seemed to result in dead trees along its roads, in spite of the Colorado DOT’s promises that it does not kill trees. Currently, rock salt is the most commonly used ice and snowmelt because it is the least expensive. Timely use of magnesium chloride reduces the amount of snow and ice to be removed, thereby reducing the overall amount of manpower and machinery required to clear roads in the event of a storm, but there are questions regarding its overall environmental safety.

Magnesium Chloride Use at Home

Before you apply any chloride-based deicer to your driveway or walkways, think of the plants and grass that normally line these areas. Any salt product is going to run into the soil--and down the drains and eventually into waterways--along with the snow and ice it has melted. Certain plants and trees are much more susceptible to sodium toxicity than others. Elevated sodium levels in your soil will effectively dehydrate your plants, so always use magnesium chloride at the lowest possible application rate. Magnesium chloride is a corrosive to concrete flatwork that is less than a year old. According to Lambert Concrete of Crown Point, Indiana, it is best to use sand for the first year of your concrete driveway or walkway’s life. Magnesium chloride is available for home use in pellet or flake form and is applied after snow or ice has covered the area in question. Sprinkle the flakes according to the directions on the bag, and remember that more is not necessarily more effective. Start with as little as possible and gauge the efficacy of that amount before applying more. The most effective way to keep snow and ice accumulation under control is to shovel it as it falls, rather than allowing it to sit and freeze. Apply magnesium chloride to whatever ice or snow you cannot remove with a shovel.


  • Arizona Department of Transportation: Know Snow in Arizona!
  • Facilites Net: Targeting Ice and Snow
  • University of Nevada Cooperative Extension: Deicers: Safety Versus Salt Damage