Substances Used to Melt Ice

Sodium Chloride

• Sodium chloride, also known as rock salt, is the principal component of edible table salt. It is found naturally in many parts of the world within sedimentary rock. Sodium chloride is a reliable agent for melting ice because as it reacts with the ice, it lowers the water's freezing point from 32 degrees Fahrenheit to about 10 F. The ice then reverts to a liquid state. Sodium chloride has no immediate danger to the handler and can be stored just about anywhere. It is important to note, however, that sodium chloride can disintegrate road surfaces over time and can harm vegetation.

Calcium Chloride

• Calcium chloride exhibits properties similar to sodium chloride. It lowers the freezing point of water to as low as minus 62 F. In addition, sodium chloride has an exothermic reaction when introduced to ice: a natural byproduct of the chemical reaction is the release of energy as heat. For these reasons, calcium chloride is the preferred method for de-icing roads and walkways in extremely cold climates. The main caveat is that calcium chloride is a skin irritant, especially if the skin in question is moist or wet; the exothermic reaction may cause burns. As such, skin protection should be worn when handling calcium chloride. It should be stored in a dry atmosphere and kept away from children and animals. Calcium chloride will harm or kill most vegetation.

Magnesium Chloride

• Magnesium chloride is yet another compound that melts ice by lowering the freezing point of water. It is a preferred method in areas where destruction of plant life is a concern, as it is far less toxic to vegetation than sodium chloride and calcium chloride. Magnesium chloride use is becoming more common among highway maintenance crews as a preemptive de-icing agent, applied in liquid form to roads and highways before the temperature drops or snow falls. Magnesium chloride has very little environmental impact. However, in the presence of magnesium chloride, the insulation used on electrical utility wiring can conduct electricity which may cause unwanted electrical arcing.

Calcium Magnesium Acetate

• Calcium magnesium acetate is a newer de-icing agent first used in North America during the winter of 1983. It is a salt-free compound; therefore, its corrosive properties are virtually nil. It has been observed to lower the freezing point of water to temperatures comparable to those found with the use of sodium chloride. Calcium magnesium acetate is the most environmentally friendly option and has had few reported cases of asphalt or concrete damage. However, achieving full de-icing in cases of extreme cold has required nearly twice the amount of calcium magnesium acetate by volume as standard rock salt.

Bleach and Chlorine

• Bleach and chlorine are products very common in homes with laundry facilities and swimming pools. While it's true that these compounds have the chemical capacity to lower the freezing point of water and melt ice, they are both highly corrosive. Concentrated bleach and chlorine can irritate the skin and eyes and cause difficulty breathing or even asphyxiation. Bleach and chlorine will almost certainly kill any plant or small animal life that ingests it. These substances can corrode most metal surfaces. Their use as de-icing agents is not recommended.