Calcium Chloride Road Improvement FAQs

Effective dust control is built first on a foundation of quality gravel and proper road maintenance. Road construction experts can help you determine the proper foundation for your needs. 

Recommended calcium chloride application rates to control dust on gravel surfaces are included below. NOTE: When applying solid products, it is usually preferable to water the surface prior to spreading the product.

The most desirable calcium chloride product for any given situation is a matter of personal choice. Solid calcium chloride products may be spread directly or dissolved in water and spread as a liquid. In the U.S., the most common liquid concentration used for dust control is 38%. In Canada, the most common concentration is 35%. Liquid concentrations higher than 38% may be used; however, higher concentrations are more likely to crystallize as the solution cools. 

To maintain optimum dust control during unusually long periods of hot, dry weather, water the road surface during early morning hours as needed to reconstitute the initial treatment. Re-apply calcium chloride in the late summer or early fall as needed to prolong dust control.

For additional information, see Use Responsibly - Controlling Dust. 

Noticeable corrosion is unlikely to occur on vehicles driven on unpaved surfaces treated with calcium chloride. However, calcium chloride for dust suppression is present in small amounts and can stay bound in the soil in the road. Therefore, it is recommended to wash vehicles and equipment if you suspect the vehicle has encountered calcium chloride.

Likelihood of damage to vegetation and grassy areas along roadsides can be significantly limited if dust control applications follow current recommendations and standard practices.

For additional information, see Use Responsibly - Managing Impact. 

A 2008 study by researchers at Colorado State University¹ and a report by the U.S. Department of Agriculture Forest Service² concluded that the impact of magnesium chloride is no less than other chlorides.

The chloride content of liquid material is determined by the concentration of the solution, and the molecular weight of the salt. For example, a 30% solution of magnesium chloride has about the same chloride content as a 35% calcium chloride solution.

Equally important in determining environmental impact is the application rate of the product. A more concentrated product can achieve the same results at lower application rates. While magnesium chloride is commercially available in 30% solutions, LIQUIDOW® is typically applied at concentrations of 35% or 38% for dust control and road base stabilization applications, which means less calcium chloride may be required to achieve the same result. 

For additional information, see calcium chloride vs. magnesium chloride.

¹Condition of Soils and Vegetation Along Roads Treated with Magnesium Chloride for Dust Suppression, B.A. Goodrich, R.D Koski, and W.R. Jacobi, March, 2008.

²Dust Palliative Selection and Application Guide, USDA Forest Service, P. Bolander and A. Yamada, November, 1999.