BLOG NUMBER 30.92
Property managers and contractors ask me some version of this question every fall: should I switch to a magnesium chloride deicer, or stick with calcium chloride? The honest answer is that it depends on your pavement, your budget, and how cold your region typically gets. In my experience running large scale winter operations for over 20 years, I have used both materials extensively, and each has a clear place in a well built snow and ice program.
What Is a Magnesium Chloride Deicer?
A magnesium chloride deicer is a liquid or granular ice melting product made from magnesium chloride salt, typically harvested from brine deposits or seawater. It works by lowering the freezing point of water, similar to other chloride based deicers, but it does so with a somewhat gentler chemical profile. Magnesium chloride is often marketed as the more environmentally conscious option because it is generally considered less corrosive to concrete and less harmful to nearby vegetation than some alternatives.
I frequently see this product used as a pre storm liquid application, known in the industry as anti icing, because it bonds well to pavement before snow arrives and helps prevent a hard bond from forming between ice and the surface.
What Is a Calcium Chloride Deicer?
Calcium chloride has been the workhorse of the snow and ice industry for decades, and for good reason. It generates heat as it dissolves, which allows it to melt ice effectively at very low temperatures, often down to negative 20 degrees Fahrenheit or colder. Having managed over 20,000 acres of pavement and 40 million square feet of sidewalks during my years at Snowmen, Inc., I relied on calcium chloride heavily during the deep cold snaps that hit the Kansas City area, since magnesium chloride alone can lose effectiveness once temperatures drop into the single digits.
The tradeoff is that calcium chloride can be harder on certain surfaces over time, particularly older or lower quality concrete, and it requires careful handling since it is more aggressive on skin and metal.
Magnesium Chloride vs Calcium Chloride: Side by Side
| Factor | Magnesium Chloride | Calcium Chloride |
| Effective temperature range | Down to roughly 0°F | Down to roughly negative 20°F or lower |
| Concrete impact | Generally gentler | Can be more aggressive over repeated use |
| Vegetation and pet safety | Considered more friendly | Moderate, can irritate paws and plants |
| Best use case | Pre storm anti icing, moderate cold | Deep cold snaps, fast melt on ice |
| Typical cost | Often higher per pound | Generally lower per pound |
Which One Should You Choose?
In my experience, the right answer usually is not one or the other. Most of the commercial properties I have consulted on benefit from a blended approach. I recommend a magnesium chloride deicer for early season applications and for properties with sensitive landscaping, decorative concrete, or heavy pedestrian and pet traffic. I recommend calcium chloride for the coldest stretches of winter, when magnesium chloride simply will not generate enough melting power to keep a parking lot or sidewalk safe.
Property managers often ask me whether switching entirely to magnesium chloride is a way to cut down on concrete damage complaints. It can help, but the tradeoff is real. If your region regularly sees temperatures well below zero, leaning too heavily on magnesium chloride can leave pavement under treated during the exact conditions when icy walkways are most dangerous. The Midwestern Regional Climate Center tracks exactly this kind of regional temperature and icing data, and I encourage contractors to review historical lows for their service area before finalizing a deicer strategy for the season.
A Few Field Notes From 20 Years of Application
Over my 20 plus years in the snow and ice industry, I have found a few practical rules hold up season after season:
- Apply magnesium chloride as a pre treatment liquid before a storm arrives, not as a rescue product once ice has already bonded to pavement.
- Store calcium chloride in a dry, sealed location since it absorbs moisture from the air and can clump or lose potency.
- Rinse equipment after using either product, since both are corrosive to unprotected metal over time.
- Train your crews on proper application rates. Overapplying either chemical wastes money and increases the risk of surface damage without improving melt performance.
- Document which product was applied, when, and at what rate. This kind of application record is something I look for constantly when I review a contractor’s winter operations, and it is one of the simplest ways to demonstrate a defensible, well run program.
As a Certified Snow Professional and an active member of the Snow & Ice Management Association since 2006, I have watched deicer chemistry and application technology continue to evolve. SIMA’s best practices guidance is a good reference point for contractors trying to keep their material selection current with industry standards.
Where This Fits Into Your Broader Snow Removal Program
Deicer selection is only one piece of a larger operational picture. I have reviewed countless snow removal contracts where the deicing chemical was specified in generic terms, with no distinction between magnesium chloride and calcium chloride, no minimum application rate, and no accountability for under treatment during a deep freeze. If your contract does not spell out which product gets used and when, that gap can quietly cost you money and increase your risk exposure. I cover exactly this kind of gap in my breakdown of what belongs in a solid snow removal contract.
Black ice is another area where deicer choice matters a great deal, since the wrong product applied at the wrong temperature can leave a thin, nearly invisible layer of ice behind. If you want a deeper look at how that hazard forms and how to address it, I have put together a guide on black ice and how to remove it.
Final Thoughts
Choosing between a magnesium chloride deicer and calcium chloride is not about picking a winner. It is about matching the right product to your climate, your pavement, and your budget, then applying it correctly and consistently. After 20 years running one of the largest snow and ice management operations in the Kansas City area, and years spent consulting with property managers and contractors nationwide, I have found that a thoughtful, documented deicer strategy is one of the most cost effective improvements a winter operations plan can make.
If you want help evaluating your current deicer program, auditing a contractor’s application practices, or building a winter maintenance plan that actually holds up under real world conditions, I invite you to reach out through my consulting services. I am happy to walk through the specifics of your property, and you can always get in touch directly to talk through your budget and climate.
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