Dear EarthTalk: Are road salts and other de-icing chemicals bad for the environment? And if, so are greener alternatives available?

Traditional de-icers, particularly chloride-based compounds such as sodium chloride, magnesium chloride and calcium chloride, can have various detrimental effects on the environment. According to the Minnesota Stormwater Manual, chloride-based de-icers contribute to soil degradation by reducing soil permeability and fertility, and by increasing soil alkalinity, which adversely affects plant growth and soil stability. These de-icers contaminate groundwater and surface water, leading to toxic conditions for aquatic life due to elevated salt levels. Vegetation damage is another issue, as chloride exposure causes osmotic stress, leading to damaged roots and foliage. Furthermore, the corrosive nature of these chemicals accelerates the deterioration of infrastructure, including roads, bridges, and vehicles.

Recognizing these issues, there are several greener alternatives to traditional de-icing chemicals. Eco-friendly de-icers, such as those offered by Green Ice Melt, use plant-based ingredients that are biodegradable, have minimal soil and water impact, and are safe for pets. These are also non-corrosive, ensuring that infrastructure remains protected. Non-chloride products, including acetate-based deicers like calcium magnesium acetate and potassium acetate, offer a less corrosive option. However, these can still deplete oxygen water due to their organic content. Carbohydrate-based deicers, derived from beet juice, molasses and corn syrup, have minimal impact and effectively reduce the freezing point ecologically.

Several other techniques can also be employed. Anti-icing, which involves applying salt brine before snowstorms to prevent ice formation and reduce the amount of de-icer needed later. This proactive approach maintains safer conditions with less environmental damage. Pre-wetting salt with brine before application enhances its effectiveness, ensuring that the de-icer adheres better to surfaces and reduces scatter, thereby improving efficiency and minimizing overall usage.

Public awareness campaigns about the benefits of eco-friendly de-icers can also play a significant role in encouraging wider adoption. Furthermore, municipalities and businesses can invest in advanced spreading equipment that ensures precise application, reducing waste and environmental contamination. Encouraging the development and use of new technologies, such as the propylene glycol and aqueous sodium formate mixture developed by Osaka Metropolitan University researchers, can further reduce the environmental footprint of de-icing operation. By making informed choices and embracing sustainable practices, we can ensure safer winter conditions while safeguarding our environment.