Magnesium Chloride

Magnesium Chloride has become the de-icer of choice in snowy regions such as Colorado. Supporters of the product claim that magnesium chloride is an environmentally safer option for de-icing than some of its predecessors, namely sodium chloride. The use of magnesium chloride, in liquid and modified cold pressed form has been show to be highly effective as a tool for de-icing in Colorado. The use of the agent has resulted in much safer travel routes for commuters and the like during wintry months.

Magnesium chloride is typically applied in two different manners depending on the surface and conditions in which it is applied. Liquid magnesium chloride is typically sprayed on dry pavement prior to snowfall, or used on wet pavement before it freezes during winter months to prevent snow from bonding to surfaces (Pavek, 2003). The use of magnesium chloride has contributed to improved highway safety in the State of Colorado. Some issues have developed surrounding the use of the de-icing agent however, related to electric utilities.

These include contamination of insulators and corrosion of steel and aluminum poles (Pavek, 2003). The advantages and disadvantages of magnesium chloride use, as well as the history and success of its use in Colorado are explored further below. In October of 2002, the Colorado Dept. Of Transportation announced that its plans for snow removal and winter maintenance include use of liquid magnesium chloride at temperatures above 16 degrees, and use of a cold temperature modified form of magnesium chloride at temperatures below 16 degrees (CDOT, 2002).

The modified version of magnesium chloride is applied to snow typically after it has coated a surface to melt frozen moisture (CDOT, 2002). The liquid De-Icer is typically applied prior to or during a storm to prevent ice formation or snow bonding on pavement (CDOT, 2002). Once the magnesium chloride successfully de-ices an area, it sits on the surface to which it was applied much like sodium chloride. Supporters of the use of magnesium chloride in Colorado have stated that the de-icer has proven beneficial to the environment.

The use of the product has according to officials contributed to the designation of Denver as a "clean-air city" (CDOT, 2002). The mag-chloride is more environmentally friendly than many of its predecessors. Supporters of its use have noted that the sodium chloride or sand used by many other states can actually become airborne and decrease air quality over time (CDOT, 2002).

The cold temperature modified magnesium chloride used in Colorado consists of a solution of up to 27% magnesium chloride, and is made from a corn byproduct additive that lowers its freezing point (CDOT, 2002). Not all people are firm supporters of the use of the de-icing agent however, even in Colorado. Some negative side effects have been determined and have sparked some controversy among highway maintenance officials. The use of magnesium chloride has been shown to possibly increase electrical outages and pole fires, because of "tracking and arcing across insulators" (Pavek, 2002).

In Colorado, three cooperatives have acknowledged that outages have increased as have pole top fires in cold months, in part due to the coating of said materials by magnesium chloride (Pavek, 2002). The insulators are coated with the de-icing agent when heavy traffic causes the magnesium chloride to rise up in a mist form and settle on the electrical equipment (Pavek, 2003). Clearly these factors are negative in nature and have caused motorists and environmental supporters some concern. One potential solution to the problem is removal of the buildup of the de-icer.

However cleanup efforts could be very costly and time consuming. Rain sometimes acts as a natural cleaning agent; however snowfall is much more likely to occur during cold months, virtually nullifying this cleansing option. Another environmental issue facing Coloradoans resulting from the use of magnesium chloride is corrosion. The use of sodium chloride or rock salt in the past presented a much greater problem in this respect.

Magnesium chloride however, is also by nature corrosive; however proponents of its use point out those chemical agents are added to it to minimize the corrosive effects (Pavek, 2002). Highway departments in the state of Colorado have noticed that the use of magnesium chloride as a de-icer has reduced much of the major corrosion on trucks and equipment, as well as steel enforced bridges compared to sodium chloride (Pavek, 2002).

However, some reports are also indicating that aluminum components and electrical components in their vehicles are actually showing increased evidence of corrosion at a more rapid rate (Pavek, 2002). Studies are currently under way to examine whether the addition of additional anti-corrosive agents to magnesium chloride may reduce corrosion without affecting the performance of magnesium chloride as a product (Pave, 2002). There is some uncertainty however, as to whether the addition of these chemicals will alter the efficacy of the product.

Magnesium chloride works by reducing the temperature that water freezes at (Snow, 2001). This chemical reaction is not without consequences however, and can be damaging to concrete and similar surfaces. Some highway agents have argued that when magnesium chloride pools in melted water along concrete surfaces, it permeates into the concrete (Snow, 2001). The ions within the magnesium may then accumulate and subsequently react with one of the components of concrete, calcium-silicate-hydrate, thus converting it into a more non-cementitious product (Snow, 2001).

Basically this means the magnesium breaks down the substance that causes concrete to aggregate and hold together, and concrete surfaces subsequently deteriorate at a rapid pace (Snow, 2001). The financial impact of such damage could be devastating. Much like the problem of clean up for build up of the corrosive material, it is unlikely financially feasible that all of the melted pools of magnesium chloride could be removed before permanent damage has occurred.

A proliference of pot holes and similar pavement problems will likely result, and could cause state transportation officials much in the ways of repair each spring unless an anti-damaging agent can actually be added perhaps to concrete. However, in order for this to be effective, all roads and surfaces within the state would have to be re-paved or treated, an unlikely solution. Magnesium chloride can also adhere to vehicle tires, and vehicles therefore bring the substance into private driveways, typically made of concrete (Snow, 2001).

The chloride can then settles in and cause the same decomposition that occurs on highways (Snow, 2001). Many opponents of magnesium treatment have pointed out that civil suits arising from driveway damage could result. Some studies have also shown that magnesium chloride may also prove corrosive to plant and vegetable life (Snow,.