Streusalze

Streusalze, or de-icing salts, are chemical compounds used to lower the freezing point of water and melt ice on roads, sidewalks, and runways. The most common salt is sodium chloride (rock salt); other commonly used salts include calcium chloride and magnesium chloride. The choice depends on temperature, traffic, environmental considerations, and cost.

Sodium chloride is inexpensive and effective down to about −9°C to −12°C, but its performance declines at lower temperatures and it can cause corrosion. Calcium chloride remains effective at lower temperatures (to roughly −25°C) and releases heat during dissolution, giving it an advantage in extreme cold. Magnesium chloride also works at low temperatures but is more costly. Alternatives such as calcium magnesium acetate (CMA) and potassium acetate offer lower corrosion and environmental risk but at higher prices; blends are common.

Application is typically by mechanical spreaders, sometimes with pre-wetted brines to improve efficiency and reduce dust. Brine solutions are applied earlier to prevent ice buildup; in areas with heavy snowfall, salt is often used with abrasive materials like sand to provide traction. Airports and highways may use specialty de-icers designed for rapid spread and long-lasting effects.

Streusalze can have environmental and safety impacts: increased salinity in soils and water bodies, corrosion of metals and concrete, and potential risks to pets and wildlife. To mitigate these effects, many regions regulate application rates and promote alternatives, such as less corrosive de-icers and best-practice maintenance, as well as non-chemical traction aids where feasible.