Article

Biobased De-Icers and Anti-Icers Save Roads, Bridges, and the Environment

Federal law and the Federal Acquisition Regulation direct that all federal agencies purchase biobased products in categories identified by the U.S. Department of Agriculture (USDA). To date, USDA has identified 139 categories of biobased products for which agencies and their contractors have mandatory purchasing requirements. One of those categories, de-icers, is particularly relevant this season.

De-icers and anti-icers are chemical products (e.g., salts, fluids) that are designed to aid in the removal of snow or ice, or in the prevention of the buildup of snow or ice, by lowering the freezing point of water. For a de-icer or anti-icer to participate in the BioPreferred Program, it must have at least 93% biobased content. Currently, there are 27 de-icer and anti-icer products listed in the BioPreferred Program's catalog, including 9 USDA Certified Biobased products.

De-icers and anti-icers are used to clear and prevent ice and snow formation on roads, bridges, airport taxiways, airport runways, parking lots, and sidewalks. They are essential for ensuring safe travel during winter months. De-icers and anti-icers can also be used in operations and maintenance to prevent freezing in water-cooled machinery and in lavatories that are exposed to the elements.

De-icing has traditionally been done with rock salt, spread by snowplows or dump trucks, often mixed with sand and gravel on slick roads. Traditional rock salts have a negative impact on transportation infrastructure, motor vehicles, and the natural environment. Rock salt causes corrosion and rusts the steel used in most vehicles and the rebar in concrete bridges. Additionally, since salt water still freezes at -18 °C (0 °F), salt is not effective in preventing freezing when the temperature falls below -18 °C (0 °F). Other deicing strategies involve the use of salts like calcium chloride and magnesium chloride, which depress the freezing point of water to a much lower temperature. However, these other salts still have negative effects on equipment, roads, bridges, and landscaping as well. Kaushal and co-authors reported, "Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans."*

Biobased de-icers and anti-icers can be generated as byproducts of agricultural operations like sugar beet refining or ethanol production and used to reduce the use of salts. Reducing the use of salt has many benefits, including reducing damage to roads, bridges, and vehicles. Accidents that occur when wildlife is attracted to salty roads are prevented. Roadside vegetation and water supplies are also less damaged. Additionally, using biobased de-icers and anti-icers may enable reduced application rates, which lowers labor, fuel, and other operational costs. Since biobased de-icers and anti-icers are often made as byproducts of materials that would otherwise be waste like corn cobs, using these materials to create de-icers and anti-icers instead helps reduce waste.

Check out the BioPreferred Program's de-icers and anti-icers in the catalog under Operations and Maintenance > De-Icers!

*Sujay S. Kaushal, Peter M. Groffman, Gene E. Likens, Kenneth T. Belt, William P. Stack, Victoria R. Kelly,
Lawrence E. Band, and Gary T. Fisher. Increased salinization of fresh water in the northeastern United States. https://www.pnas.org/content/pnas/102/38/13517.full.pdf, accessed January 2021.