Winter Weather Tools

Sodium chloride, calcium chloride, abrasives -- What's the difference?

The Virginia Department of Transportation applies several materials to Virginia's roads to assist with snow removal or to improve vehicle traction. Here is a description of these materials:

Sodium Chloride - For snow and ice control, a chemical called sodium chloride - or salt - is the most plentiful and inexpensive deicer. It is mined from the earth as rock salt or distilled from seawater. When salt is applied, it creates brine, which keeps snow and ice from bonding to the pavement. Salt is effective to temperatures of about 27 degrees Fahrenheit and above.

Calcium Chloride - an expensive deicing chemical - is most often mixed with salt to provide some moisture content so the chemical reaction causing melting can take place. It is used when temperatures fall into the low 20s because moisture is not present to help salt start the melting process. In liquid form, calcium chloride provides quicker action.

Abrasives - small gravel or sand - cannot melt snow or ice. Often abrasives are mixed with salt to provide additional traction and lessen the cost of applying chemicals. Abrasives can be used on roads generally not treated with chemicals. Deicing chemicals such as salt and calcium chloride are very detrimental to gravel-surfaced and surface-treated roads (those roads that have a salt-and-pepper appearance). Therefore, chemicals are used very sparingly on these types of roads and only when absolutely necessary.