Toxicological Effects of Chloride-Based Deicers in the Natural Environment: Synthesis of Existing Research

State departments of transportation (DOTs) are continually challenged to provide a high level of service (LOS) on winter roadways to improve safety and mobility in a cost-effective manner, while at the same time minimizing adverse effects to the environment, vehicles, and transportation infrastructure. This work presents current and previous research to develop a better understanding of the impacts of chloride based deicers to the environment. Information presented to date in the published domain generally includes chemical composition and engineering properties of deicers; and additional information on their aquatic toxicity is much needed to enable fully-informed decisions by stakeholders. Toxicity associated with the direct effect of deicers or with the indirect effect via their interactions with runoff chemistry is presented.