Ice melting products are chemicals that lower the freezing temperature of water by attracting moisture and generating heat. Different ice melt products offer different benefits depending on what ingredients they contain, and how the products are applied (e.g., granular, liquid).
For example, sodium chloride (“rock salt”) offers traction and melts ice quickly by lowering the freezing point of water, but it can be damaging to concrete surfaces and is corrosive when left in contact with steel or wood. Another common ice melt product, calcium chloride, has a lower freezing point but does not offer the same traction as sodium chloride and requires a longer time for ice to be completely melted. In contrast, liquid ice melt products like magnesium chloride and calcium magnesium acetate generate a lot of their own heat when they dissolve, helping them to melt ice faster than air temperatures alone can.
Aside from their practical applications, ice melt products also help to reduce sea level rise by adding freshwater to the oceans. This water comes from the melting of glaciers and ice sheets, which adds to the overall volume of the world’s oceans. NASA’s twin GRACE satellites continuously measure the weight of glaciers and ice sheets – and the resulting changes in global sea levels.
The chemistry behind the ice melt science is pretty cool. When water freezes into ice, it forms a very rigid crystalline lattice that relies on strong hydrogen bonds between the molecules. When ice melt chemicals get introduced, however, they crash this molecular party by disrupting the energy pathways that the molecules use to stay together in solid form.