Ok I have had enough snow and ice for the winter. Although I say I am done, I know there is more to come, so lets learn to deal with it. That sheet of black ice on top of my driveway and sidewalk needs an ice melting product, but which one and what is the difference in the products I find in the local hardware store? The answer is in the chemical makeup and temperatures at which they are most effective.

There are five different deicing products readily available;  Sodium chloride (rock salt), calcium chloride, potassium chloride, magnesium chloride and calcium magnesium acetate. You may find these products packaged individually or two or more combined together to take advantage of their different ice and snow melting qualities.

Sodium chloride (rock salt) (NaCl) is the old standby. It is commonly available,  widely used for decades and inexpensive.  As sodium chloride dissolves, it releases the most amount of chloride ions causing the most damage to surfaces and plants. Chloride can corrode metal and seep into ground water, and streams and rivers causing pollution. It is most effective melting ice above 20° F. It will not work below 16° F.

Calcium chloride (Cacl2) will melt snow and ice at a much lower temperature, down to 25° F. It comes in different forms, white pellets, flakes and liquid.  Its down side is it can cause skin irritation if handled and is easily washed away from where it is used meaning you must reapply it more frequently than some of the others. It can also cause damage to concrete surfaces like sidewalks. It can damage plants if it is overused or concentrated in areas such as road sides and under  repeatedly added to snow piles.

Potassium chloride (KCl) works when the air temperature is above 15° F. It is commonly used as a fertilizer for plants but too much will burn plants. It will melt ice until the air temperatures reach 12° F.

Magnesium chloride (MgCl) is less damaging to concrete, plants and trees. It is the new kid on the block and may be referred to as ‘environmentally safe’.  It melts ice and snow down to -13° F. Magnesium chloride will not leave a white residue on shoes or floors and claims to be gentler on vegetation. It release 40% less ions than calcium chloride making it less toxic to the plant life and less harsh on concrete.

Calcium magnesium acetate (CMA) is made from dolomitic limestone and acetic acid. It is a new salt-free product. It is  effective to 25° F. It is most costly better easier on the environment and vegetation and concrete. CMA prevents ice particles from sticking to each other.

Always read and follow label directions when applying deicing materials.