At What Temperature Does Road Salt Stops Working?
During the winter season, we face the challenges of slippery roads. So, road salt is widely used as a deicing agent. It is an effective yet affordable commodity that prevents the roads from slipping and prevents accidents by improving their traction. But have you ever wondered at what temperature does road salt stops working? Understanding this concept can help homeowners and municipalities to effectively use salt during winter months. In this article, we will explore it more.
How Does Road Salt Work?
Road salt, also known as sodium chloride, lowers the freezing point of water. When salt is sprinkled, it interferes with ice formation, which is called freezing point depression. Salt works on ice by creating a brine layer between the snow and the road surface that requires a lower freezing temperature than water. However, the salt can gradually lose its effectiveness as temperatures drop and cannot prevent ice formation.
At What Temperature Does Road Salt Become Ineffective?
The road salt works on the temperature. As the temperature decreases, its effectiveness also decreases. Below, we have mentioned the clear breakdown:
- Above 20°F (-6°C): Road salt is highly effective at melting ice at this temperature. Sodium chloride creates a brine that prevents ice formation.
- 15°F to 20°F (-9°C to -6°C): At this temperature, the brine is less concentrated and less effective. Road salt still works but takes longer to melt the ice. In these conditions, additional techniques need to be followed to maintain effectiveness.
- Below 15°F (-9°C): Road salt efficiency starts to drop slowly. The brine solution struggles to keep water in a liquid state, and ice forms even after the salt is present. At this temperature, sodium chloride needs to be combined with other chemicals like calcium chloride or magnesium chloride.
- 10°F (-12°C) and Below: Road salt becomes almost ineffective at very low temperatures. At this point, it can’t lower the freezing point enough to stop ice from forming. Instead of melting the ice, the salt can get trapped inside the ice, making the roads even more slippery and dangerous.
- 0°F (-18°C) and Lower: Road salt completely stops working at extremely low temperatures because the brine will freeze at this point. Other deicing options, like calcium chloride or magnesium chloride, can be used instead.
Alternatives to Sodium Chloride for Extreme Cold
When the temperatures drop, sodium chloride becomes ineffective, and it is advisable to use other alternatives. Below, we have mentioned some of them:
- Calcium Chloride (CaCl₂): Calcium chloride is a popular choice and is used as an alternative when sodium chloride stops working. It is effective even at -25°F (-32°C). It creates a more concentrated brine solution that helps melt ice even in severe conditions.
- Magnesium Chloride (MgCl₂): This salt works well at -15°F (-26°C) or even less. People choose it because it is less harmful to the environment than regular salt and calcium chloride but costs more.
- Potassium Chloride (KCl): Potassium chloride works down to 12°F (-11°C) and is better for the environment, but it’s used less often because it is more expensive.
- Brine Solutions and Additives: Some cities use pre-wetted salt or a brine solution mixed with other chemicals to make sodium chloride work longer. This helps the salt stick better to roads, but it still doesn’t work well in extremely low temperatures.
Why Road Salt Loses Effectiveness in Extreme Cold
Road salt stops working in very cold temperatures because of freezing point depression. Salt will begin to work when moisture is on the road by creating a brine solution with it. As temperatures get colder, there is less moisture in the atmosphere and on the ground, making it harder for the salt to dissolve.
The brine formed at low temperatures becomes inefficient because it can’t stay liquid as it gets colder. Eventually, it freezes along with the ice, making roads even more dangerous. In such cases, it’s often better to use sand for traction instead of relying only on salt.
The Environmental Impact of Road Salt
While we consider road salt an effective tool for safety during winter, it comes with certain drawbacks. These concerns have led certain municipalities to think of other alternatives to sodium chloride. The environmental impacts are
- Soil and Water Contamination: Salt can gradually seep into the nearby waterways and surroundings, increasing the salinity of the water bodies and harming aquatic life and other wildlife.
- Corrosion: Sodium is known for corroding metal surfaces, roads, and other infrastructure, which can result in expensive repairs.
- Vegetation Damage: Salt can cause dehydration to the plants and trees by drawing moisture from them.
Best Practices for Using Road Salt
Below are some of the best practices to ensure effective usage of road salt
- Apply Salt Early: Applying salt before ice forms helps create a barrier and makes it easier to remove snow and ice once precipitation starts.
- Use the Right Amount: Using more salt than needed doesn’t speed up the melting process and can lead to wastage and environmental harm.
- Mix Sand: Mixing salt with sand can provide traction even when temperatures fall too low for salt to melt the ice.
- Pre-wetting: Mixing road salt with a liquid deicer before application helps it stick to the road, start working faster, and reduce salt usage.
- Brine Solution: Applying salt brine directly to the road can prevent ice formation. This proactive approach is often used before a storm hits.
- Blending Deicers: Combining different deicing chemicals can improve their effectiveness. For example, blending sodium chloride with calcium chloride can lower the effective working temperature.
Conclusion
Road salt is an essential tool for maintaining roads during the winter. But, it has certain limitations. Sodium chloride is highly effective at or above 20°F. It becomes less effective below 15°F, losing its effectiveness around 10°F and lower. Understanding these limitations helps ensure that road salt is used efficiently and that alternative methods are employed when temperatures drop too low. If you are looking for reliable deicing solutions, we are here for you! At Canada Salt Group Ltd, we offer high-quality bulk road salt and salt products. Contact us today to find the best solution for your winter needs and ensure safety throughout the season!