Salt as a de-icing method

Every winter, high mountain areas and territories that reach sub-zero temperatures are covered with ice and snow, creating potentially dangerous situations for traffic. In this context, the most prone areas tend to be pre-supplied with de-icing methods such as salt, the most common and effective solution to ensure road safety and keep traffic flowing smoothly.

Why is salt used for de-icing?

The key lies in its ability to reduce the freezing point of water. Water freezes at 0 °C, but by adding salt (NaCl), the freezing temperature is significantly reduced to -21 °C. This phenomenon, known as cryoscopic lowering, is what prevents water from freezing at low temperatures and facilitates the thawing of existing ice.

Therefore, salt does not melt ice per se, but acts as a hygroscopic agent, meaning it has the ability to attract and retain moisture from the environment. Consequently, even in conditions of low humidity, salt manages to dissolve part of the ice or snow, thanks to the aqueous layer that is created on the ice and accelerates the thawing process, improving adherence to the road.

Types of salt used for road de-icing

Salt, due to its low cost and effectiveness, is the substance most commonly used to prevent ice formation. However, in more extreme circumstances, other compounds, such as calcium chloride, with a more aggressive hygroscopic behavior acting at lower temperatures, are used. Because of their hygroscopic properties, these compounds require more complex and costly storage systems, to ensure airtightness so that they are not exposed to humidity before and during application.

Quick response requires preventive maintenance

Although road de-icing can be planned in advance if frost is expected, sometimes an immediate response is required. The most effective way to avoid traffic complications is to act preventively and keep ice from forming on the roadway. For this reason, it is essential to have the necessary stock, as well as a quick response from road maintenance staff. This preparation not only minimizes risks for drivers, but also reduces the costs of emergency interventions. Anticipating or acting quickly is not only a question of efficiency, but also of safety. Although there are other alternatives that cover needs in more extreme environments, salt, due to its easy storage and application, and its effectiveness in areas with moderate winters, is still the most widespread option today.