Substances used to combat ice have side effects
Anyone who knows the signature discomfort of a Montreal thaw — Bit of Gravel Inside Boot (and its advanced stage, Bit of Gravel Inside Sock) — has knowledge of our city’s abrasives program.
Vélo Québec’s Bartek Komorowski reminds us not to confuse abrasives with melters. Salt is a melter, gravel is an abrasive.
“We used to use sand on the sidewalks, but it gummed up the métro escalators,” Komorowski said. “So we use a stone that is crushed to a size that will not penetrate the escalator stairs.”
The most common product used to melt snow and ice is rock salt, which often contains additives made from beet or corn sugar, or sometimes cheese byproducts, to extend the temperature range over which they work and to help them stick to road surfaces.
Komorowski said liquid melters like salt brines that form a non-stick surface against the pavement are good for pedestrians, infrastructure and the environment, because they release up to one-third less salt onto the roads than rock salt.
“All that salt corrodes our infrastructure, it destroys vegetation and trees in the city, and it ends up in the Saint Lawrence. It also destroys our underground infrastructure,” he said.
That’s not all: salt is hard on bikes, cars, shoes and clothing.
“Reducing salt use isn’t really on the radar as far as municipal politics goes, but it should be, and it would have major benefits,” Komorowski said.