Corrosion Threat of De-Icing Salts and Road Salts


Corrosion Threat of De-Icing Salts and Road Salts

For regions that experience snow, ice and freezing rains during the winter months, de-icing salts are a common method of keeping roads safe. However, numerous studies throughout the years have shown road salts to be hazardous to the environment. The chemical make-up of salts used for de-icing purposes can include sodium chloride, calcium chloride, potassium chloride and magnesium chloride. When these small compounds are released into the environment, they can upset the existing balance of the ecosystem and affect the wildlife and plant life that reside there.

To see the damage that road salts can cause, one only needs to look at the corrosion they can cause on buildings and architecture. So undeniable is the evidence of road salt corrosion that the damage done is often compared to coastal architecture corrosion caused by natural sea salt. Buildings that are located in coastal regions experience corrosion from the abundant amount of sea salts that are released into the air and carried by wind, rain or traffic. Basically, that means that comparing the weather and humidity in an area where road deicing salts are used, to a coastal region, provides a real world model of how much damage results from the use of road salts.

Damage is not limited to architecture and buildings close to where salts have been used, either. Moving vehicles, and especially heavy duty types, cause road salt mists to form in the air. These mists consist of either salt water or dry particles, which, depending on the environmental factors involved can travel up to 1.2 miles from the treated area. In some studies, it has been reported that road salt particles were present as far up as the 59th floor of buildings.

However, de-icing of roads are a must for many regions. Ice-related highway and business closures can have significant economic impact and costs. The United States alone uses between 13.6 to 18 million metric tons (or 15 to 20 million tons) of de-icing salts per year as reported by TMR Consulting. In Canada, 3.6 to 4.5 million metric tons (4 to 5 million tons) are used per year. 70% of roads and populated areas in the United States experience snow, ice or freezing rain during the winter months. Considering the size of the geographic area that requires de-icing of roads, the negative impact of utilizing road salts is multiplied.

Despite compelling evidence of negative impact on the environment, the use of road de-icing salts continues to grow. Even ‘sunbelt’ cities and towns are stocking salt in the event of freezing rains. De-icing Salts are the cheaper option for keeper roads safe during winter months, but its negative implications on the environment must not be forgotten.