With New York City slushing through its third snowy weekend of the new year, a couple of folks have asked me about greener alternatives to conventional salt to de-ice sidewalks. The reason to avoid traditional salt, if possible, is that Sodium Chloride (NaCl, traditional rock salt) contains cyanide and choride. Both poison soil and water as the snow melts. Remember, everything you put on the sidewalk eventually ends up in the gutter and in time local waterways.
Better options are:
* Calcium Magnesium Acetate (CMA) which is far less toxic than salt, and works down to temperatures of 22°F, or
* Calcium Chloride (CaCl) which is more potent than salt, so can be used in smaller amounts, and works down to -25°F. Though it has no cyanide, there is still some chloride impact.
Read more here: http://blog.mlive.com/watershedwatch/2009/01/picking_the_right_deicing_prod.html