Snow can be fun. We sled in it. We ski in it. Nothing is sweeter than the sound of children’s voices yelling and giggling when playing in the snow. This idyllic scene has its down side. The snow piling up on the streets, sidewalks and people stranded at home. Rock salt is mostly used to melt the ice. This allows cars to drive and people to walk on the sidewalk. The reason rock salt is common, is that it is cheap and available. It works well because it is capable of lowering the temperature of water.
Recently, research has shown that rock salt has an adverse effect on the environment. It is toxic when it bleeds into the soil and contaminates the water system. It kills grass, plants and trees. It corrodes the underside of automobiles, as well as, the metal in building material of freeways, bridges and rail road tracks. Rock salt damage can be counteracted by not allowing it to build up. The following are alternatives to rock salt and how they work.
MAGNESIUM CHLORIDE This is a natural way to deice the roads but it is highly corrosive.
CALCIUM CHLORIDE Comes in various forms: flake, pellet, liquid. It has properties that cause exothermic reaction. It dissolves quickly, which starts the melting process.
POTASSIUM CHLORIDE This is a natural substance used in fertilizers. It is not the best deicer because it contains so much salt and destroys vegetation.
CALCIUM MAGNESIUM ACETATE It is salt-free and made of dolomitic limestone. It does not seem to damage concrete nor plants.
An environmental group, Green Venture, have commented on the above deicers as a part of the safety of the environment. Environment Canada did a five-year study on the effects of road salts. They found that, in addition to rock salt (sodium chloride), the following deicers were pollutants under the National Pollutant Discharge Elimination System (NPDES): calcium chloride, potassium chloride, magnesium chloride and ferrocyanide salts.
Some recommendations on the market labeled “environmentally safe” are not necessarily effective: a. Kitty litter and ashes do not melt snow. b. Urea-based deicer is not only expensive but performs poorly under temperatures of below 6 degrees C. Urea has nitrogen. If washed into our waterways, it will add to the problems we already have with pollution of our water. South Dakota Department of Chemistry and Chemical Engineering has done tests on Ice Shear. It is an environmentally safe deicer. It is made of equimolar sodium acetate and sodium formate. This is an economical alternative to the other deicers reviewed earlier. The studies show minimal environmental impact. This is just one of the many explorations into developing environmentally safe products. It is essential to find an affordable method to deice and research seems to be coming closer to finding a solution.
