Used as an icemelter, Calcium Magnesium Acetate (CMA) is biodegradable and non-corrosive, but it is expensive to produce and hard to apply. How can its beneficial features be realized while its drawbacks are overcome?
Calcium Magnesium Acetate (CMA) is a relatively recent addition to the arsenal in the fight against road ice. It is a major ingredient now found in Arctic ECO Green ® Icemelter on the market, made by XYNYTH Manufacturing Corp. A common question asked, is exactly what is CMA, and is it a realistic ECO choice? ®
It is made by reacting acetic acid (the costlier component) with dolomite lime. Acetic acid is derived from natural gas or other petroleum products, but can also be made from agricultural waste. When people talk about corn-based icemelters, CMA is generally what they have in mind.
One of the great features of CMA is the fact that it is biodegradable, and that according to the Texas DOT it breaks down into CO2 and H2O – so it is pretty harmless for roadside vegetation. It biodegrades in two to four weeks (depending on ambient temperatures), and does not harm soil structures like Rock Salt does – which makes soil cloddy and impermeable. CMA therefore discourages erosion by permitting plant life to properly take root. It is has poor mobility in soil so that unlike salt, it is not likely to reach groundwater sources.
Not only that, it is non-corrosive, according to the EPA Airport De-icing publication (p.9-26). This is significant not only for automobiles but also for highway materials like rebar, steel bridge components, pavement, road marking materials, and concrete. Some bridge decks and parking garages are so contaminated with rock salt that they will continue to deteriorate, according to The Transportation Research Board in Washington, publication (p.3, p.5) regardless of what icemelt products are used on them. Even if we stopped using rock salt today, we would still be faced with ongoing replacement and repair costs for these structures for many years to come, thanks to the overuse of rock salt.
CMA is not just a pretty face either. It is a powerful icemelter effective to -28˚ C, according to a report put out by the Alaska Department of Transportation and Public Facilities (p.9) and that’s a lot better than the -9˚ C generally achieved by rock salt.
The cost for CMA is much higher than for rock salt, but there are a lot of indirect costs related to the use of salt. One study, by the National Center for Agricultural Utilization Research, showed that annually, the State of New York incurs expenses due to salt damage in excess of $1 billion, caused by spreading about a million tons of salt. This works out to an economic loss of more than 50 cents per pound of salt used; this does not include costs like compromised human health due to sodium contamination of water sources.
CMA is a little more complicated to apply than rock salt, however, because the timing of application is more important. It is best if it is applied early in the storm and the lower density (p.9) of the material means that it can be blown off a roadway in high winds. Further, greater quantities are generally applied compared to rock salt, so higher capacity trucks may be needed if CMA is applied to roadways.
In order to mitigate some of these drawbacks, an icemelt blend is recommended. Arctic ECO Green ® is just the thing. It utilizes sophisticated manufacturing techniques to coat rock salt icemelt crystals with CMA – thereby overcoming the low density problem – so it won’t be blown off the sidewalk or roadway. The crystals are then further coated in multiple layers of Potassium so that the effects of the rock salt are mitigated by the CMA and the fertilizer qualities of the potassium. The corrosive effect of the salt is offset by the CMA and the harm to vegetation is counteracted by the fertilizer. Arctic ECO Green ® is one small step for planetary health.