Surprising ingerdient keeps roads safe in summer and winter
Courtesy of ARA Content
The versatile ingredient used to help turn soy milk into tofu and to give a boost to sports drinks also can make streets and highways safer during summer as well as extreme winter weather.
A naturally-occurring type of salt, magnesium chloride, is found in sea water or brines extracted from salt beds found in nature, such as the brine of the Great Salt Lake in Utah. When applied to roads and streets during cold weather, magnesium chloride reduces the temperature at which water freezes, melting snow and ice when temperatures dip as low as minus 10 degrees Fahrenheit, keeping traffic moving. Its effectiveness in lower temperatures makes it a good fit for road crews working in colder climates or in areas experiencing colder-than-normal temperatures.
Even when the weather warms up, magnesium chloride can help make roads safer. In summer, when dry conditions can create road dust that obscures drivers’ vision, road crews often continue to use magnesium chloride for erosion and dust control on unpaved surfaces. Once applied, it attracts moisture from the air to create a compact, smooth roadway, providing stability and control for months. North American Salt Company offers magnesium chloride for dust control under the DustGard name.
In winter, magnesium chloride is most effective when applied twice as part of a total de-icing program. The first application, experts say, should occur before storms hit. The liquid product is sprayed on the road, preventing falling snow and ice from bonding to the road surface. Road maintenance personnel refer to this application as anti-icing.
As winter weather continues, a second magnesium chloride application—this time sprayed directly on salt before it hits the road—quickly cuts through ice and any accumulated snow-pack. This two-part application method is an efficient way of providing safer roads and highways in extreme weather.
This is especially good news for climates that typically are too cold for traditional rock salt to be effective. While rock salt does a good job clearing most roads and making roadways safe, it begins to lose some of its effectiveness once pavement temperatures reach 15 degrees Fahrenheit.
Not only is magnesium chloride powerful in colder temperatures, it can be a more environmentally friendly way to provide safer driving surfaces, says Jason Bagley of North American Salt Company, which markets highway de-icing magnesium chloride products under the name FreezGard. “Once temperatures get really cold, highway departments sometimes mix sand with rock salt to provide traction,” Bagley says. “But sand is difficult to clean up once spring arrives. It can be hard on vegetation near roads and on natural waterways like lakes and streams, and it can reduce air quality.” Because magnesium chloride continues to work in lower temperatures, it is often unnecessary to use sand for traction.
Since magnesium chloride works at lower temperatures for longer periods of time, transportation departments find they use less de-icing product and can increase the size of their coverage area. It’s a cost-effective way of providing safer roads during cold winter weather. Additionally, magnesium chloride is less corrosive to metal than traditional de-icing products, reducing equipment maintenance expense.
Homeowners also can clear sidewalks and driveways with magnesium chloride. When packaged for home use, dry pellets or crystals of magnesium chloride can be sprinkled over concrete or pavement to melt ice and prevent it from sticking. And since it is less toxic than baking soda, according to the U.S. Department of Health and Human Services, pets or wildlife aren’t harmed when they come into contact with it.
“Magnesium chloride comes from natural sources, and in our case, we use solar energy to concentrate it from brine in the Great Salt Lake to use on roads for both ice and dust control. Drivers get the best of both worlds—a natural product that’s so effective you can reduce application rate on the roads,” says Bagley. Look to magnesium chloride for dust control during summer and ice and snow removal in winter to make your driving experience safer.
From the March 24-30, 2010 issue