Ice Melters

Penn State Extension, Franklin County, 181 Franklin Farm Lane, Chambersburg, PA 17202
Telephone: 717-263-9226

http://extension.psu.edu/franklin

There are five main materials that are used as de-icers:  calcium chloride, sodium chloride (table salt), potassium chloride, urea, and calcium magnesium acetate. Calcium chloride is the traditional ice-melting product. Though it will melt ice to about -25 degrees F, it will form slippery, slimy surfaces on concrete and other hard surfaces. Plants are not likely to be harmed unless excessive amounts are used.

  

Rock salt is sodium chloride and is the least expensive material available. It is effective to approximately 12 degrees F but can damage soils, plants and metals. Potassium chloride can also cause serious plant injury when washed or splashed on foliage. Both calcium chloride and potassium chloride can damage roots of plants.  Urea (carbonyl diamide) is a fertilizer that is sometimes used to melt ice. Though it is only about 10% as corrosive as sodium chloride, it can contaminate ground and surface water with nitrates. Urea is effective to about 21 degrees F.

 

Calcium magnesium acetate (CMA), a newer product, is made from dolomitic limestone and acetic acid (vinegar). CMA works differently than the other materials in that it does not form a brine-like salt but rather helps prevent snow particles from sticking to each other or the road surface. It has little effect on plant growth or concrete surfaces. Performance decreases below 20 degrees F.

  
Limited use of any of these products should cause little injury. Problems can happen, however when they are overused, or there's too little rain to dilute them, so resist the temptation to over apply just to make sure. Overuse can damage the plants and grass growing along the walks and driveways, and symptoms may not show up until spring or summer.