How Icy Road Emergency Salt Works

Description

• Salt is a chemical compound known as sodium chloride. It occurs naturally as the mineral halite and can be found in seawater, salt lakes and on the surface as residue from ancient seas. Salt is cubic in shape and can be colorless, white, gray or brown. It dissolves in water. Salt is obtained by mining underground deposits or extracting it from oceans and saline lakes. Its supply is inexhaustible, according to the Salt Institute.

Function

• Salt lowers the freezing point of water. Any substance that dissolves in water has the potential to lower the freezing point to varying degrees. Salt's low molecular weight makes it highly effective. Salt begins working when it dissolves into brine, which is a solution of sodium chloride and water. It then acts immediately, destroying the bond between snow or ice and pavement. Salt can be applied as a liquid or pre-wet solid. Dry salt blows around and does not work as quickly. Liquid salt applied before storms hit will prevent snow or ice from bonding to the pavement. Pre-wet salt is applied when roads are already ice-or snow-covered. Use multiple applications of salt during intense storms because large quantities of snow and ice dilute the brine and reduce its effectiveness.

Benefits

• Use of salt on streets and roadways reduces traffic accidents by improving vehicle traction, according to the Salt Institute. Salt makes roads more accessible to emergency vehicles and the public. Road accessibility also reduces lost wages and revenue for businesses.

Environmental Effects

• Salt run-off and melting snow piles left by plows affect roadside vegetation. Chloride reduces plants' moisture absorption and can brown or scorch leaves. It also alters soil structure and reduces its aeration, which may affect plant growth. Salt infiltrates groundwater, which may increase salt concentrations in aquatic systems. Some animals cannot survive in high levels of salt. Storing salt on an asphalt base and keeping it covered helps prevent run-off.