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Calcium Chloride and Magnesium Chloride as Dust Control Solutions

Calcium Chloride and Magnesium Chloride as Dust Control Solutions

Justin Rollin

Dust suppression products help preserve the natural environment, people’s health, and the longevity of equipment and machinery. Calcium chloride and Magnesium chloride are the two most popular dust control solutions in Minnesota. As chlorides, they maintain and stabilize unpaved roads and work sites.

While similar products, their chemical makeup is marginally different, and the rate of application varies, as does effectiveness according to the environment and concentration. Let’s find out more about these viable dust control solutions.

What Are Dust Suppressants?

A dust suppressant is a material used to control floating particle matter. Commonly used suppressants include; salts like calcium chloride and magnesium chloride, as well as organic petroleum products, like asphalt emulsions, or organic non-petroleum products such as vegetable oils and tall oil.

The best working dust suppressant products use water treated with special additives called chemical polymers, which attach themselves to the particle matter in airborne dust and stop them from floating around the air.

Magnesium Chloride for Dust Control

Magnesium chloride is also a high-performance dust suppressant, and soil stabilization agent used to extend the life of gravel roads and surfaces. It’s an inorganic salt compound that has one magnesium and two chloride ions. Like calcium chloride, it is also hygroscopic and deliquescent, meaning it has the ability to absorb moisture from the air and hold dust particles down.

Magnesium chloride is one of the most popular dust suppression methods in the Western United States because much of it is locally sourced from the salty waters of the Great Salt Lake in Utah. It can be purchased and applied as flakes, pellets, or as a liquid.

Having been used as a dust suppressant since the early 1920s, it has a long history of dust control. Its longevity depends on the application, climate, traffic conditions, and other variables. Some roads require only one application per year, while others require two or more.

Magnesium chloride works the same way as calcium chloride. A single application can reduce issues associated with; dust contamination to crops, vehicle and machinery maintenance, injury from flying stones and loose gravel, impaired driver vision due to disturbed dust, and dust-related respiratory problems.

Calcium Chloride as Dust Suppressant

Calcium Chloride

Calcium chloride is a simple material manufactured from natural brine deposits found underground or from the synthetic Solvay process. The Solvay process entails obtaining the material from limestone, ammonia, and brine. It is processed into a colorless, odorless liquid, which is primarily used as a dust suppression product on unpaved roads. It can also be processed into white flakes and white pellets.

As a hygroscopic dust suppression chemical, calcium chloride attracts moisture from the air and surroundings. Compared with plain water, it has a stronger moisture film, higher surface tension, lower vapor pressure, and lower freezing point. This combination enables the chemical to keep unpaved surfaces damp and tiny dust particles in place.

For example, when applied to a road, it keeps the surface damp and the dust down, even in hot conditions. Its moisture film provides a cohesive force that binds aggregate particles together, resulting in a hard and compact road surface.

Calcium chloride also resists evaporation, which significantly enhances a single application’s effectiveness over time. One of the benefits of calcium chloride is its accumulative effect after each application. As the chemical seeps deeper into the surface it's applied to, its stability improves, and frost damage is prevented.

Benefits of Magnesium Chloride and Calcium Chloride for Dust Suppression

As go-to dust suppression products, both magnesium chloride and calcium chloride offer many benefits: 

  • Better roads: Dust suppressant products reduce erosion and subsequent potholes, wash boarding, and ruts, keeping roads hard and durable.
  • Lower maintenance costs: Better roads mean fewer repairs and cost savings in labor and materials required for eroding roads.
  • Improved safety: When dust is kicked up, it impairs driver visibility. Vehicles can lose traction, drive slower, or have to stop more frequently along the road.
  • Environmental protection: Effective dust control prevents fine particles from damaging crops and contaminating water sources.
  • Reduced vehicle damage: While a dusty car is a surface problem, unpaved roads can damage gravel windshields chipping paint, and negatively affect steering.

Magnesium Chloride vs Calcium Chloride Dust Control Solutions

Magnesium chloride vs calcium chloride dust control solutions weighs in fairly evenly. Both materials are similar in effect and even price point, so the choice typically comes down to application and road type. 

  • Solution characteristics: In hot, dry weather, calcium chloride remains liquid, whereas magnesium chloride solidifies and provides little if any, dust protection. While both dust suppressant products work by attracting moisture from the air, it appears calcium chloride is more effective in varied environments.
  • Chemical concentrations: Calcium chloride products are available in higher concentrations, meaning that more magnesium chloride will be required to control dust on the same length of road.
  • Environmental safety: Any chloride-based dust suppression product can harm vegetation and soil. However, on the whole, magnesium chloride is considered safer for plants, water, people, and animals. Due to this, it is typically used in a sensitive watershed and wetland locations, as it won’t disturb natural habitats located around roads or construction zones.
  • Cost: The primary advantage of both chlorides resides in their cost. They are both cost-effective options, with magnesium being the marginally cheaper choice of the two.
  • Corrosiveness: According to studies conducted by the National Association of Corrosion Engineers, magnesium chloride is more corrosive to metals and may affect vehicles repeatedly driving the same route.


Maintenance of dust control on roads, agriculture, and construction sites is crucial for the health and safety of anyone working or passing through the area; this includes humans, plants and animals, and even machinery and equipment. Regardless of which dust suppressant product you choose, one of the most important features to look for is how environmentally friendly it is.

At Ninja De-Icer, we have a premium selection of quality rock salt products at competitive prices to suit a range of applications. From Sizzle Professional Rock Salt to Super Melt Rock Salt, whether you’re looking for calcium chloride or magnesium chloride, you’re bound to find a product perfect for your needs. Contact us for additional recommendations about trusted products!