Just what is that ice melter made of?

 

Don't let Anyone Break a Hip on YOUR Sidewalk this Winter

   Lawyers love slippery sidewalks, which is all the reason anyone needs to make sure their sidewalk is as clean as clean can be.  Sometimes, though, it's just not possible to get out there and chip away the 3 inch layer of ice that's built up after a Chinook has passed.  So here's a run down of what you can use to be sure that no one is going to take a tumble down the litigation trail at your expense.

     Commercially produced ice melters are all the rage, growing in popularity as sure as suing.  But what's in these things?  Do they live up to the claims on the bags?  Why does my dog throw up a few hours after I walk him in the winter?  Here's what most manufacturers use in their deicers:

1.  Salt:   We all know rock salt (NaCl) as the Go-To ice melter from way back.  It's cheap, effective as long as it's not too cold, cheap, easy to find, and cheap.  But it's only cheap if you ignore corrosion problems as it refreezes and expands repeatedly in cracks in concrete and metals.  Factor in concrete replacement, vehicle depreciation, and landscape repairs into your cost analysis to see if cheap is better.  It probably isn't.

   Magnesium Chloride is used largely as a liquid pre-snowfall application when temperatures aren't expected to dip below -15°C.  It's effective in preventing ice build up before it happens, and is a better choice for areas with vegetation nearby as it's far less toxic to plants and animals than rock salt.

     Calcium Chloride will effectively melt ice in temperatures down to -25° which makes it the first choice of many municipal roads departments.  CaCl will also start working almost immediately, making it a good choice for office buildings where those "first-in" staff arrive as the snow removal crew is applying ice melter.  Because the re-freezing point is so low, it also prevents a lot of damage to concrete and asphalt.  Note that I said "a lot" and not "all."  Calcium Chloride will still refreeze when it gets cold enough, but because that threshold is so low, it's far less damaging than rock salt or Magnesium Chloride.  Two major warnings about Calcium Chloride - read the application rate; if too much is put down, it can create a slippery, oily film, totally defeating the purpose of melting the ice in the first place.  And CaCl is not much better for plants and animals than rock salt.

     Some manufacturers claim Potassium Chloride to be the best choice for customers concerned with their plants and animals' well being.  Because potassium is an essential nutrient for plant growth, manufacturers argue that potassium Chloride is good for plants, but in a winter with heavy, persistent snow a lot of Potassium Chloride can build up in snow banks and cause some damage in the spring when it melts out and the plants start trying to grow.  That said, KCl is far better than any of the other salts when considering plants and animals - it's just that it's the lesser evil, not the solution.  It is also extortionately expensive, and not much more effective than rock salt in low temperatures.

2. Acetates

     Calcium Magnesium Acetate (CMAc) is far less corrosive than any of the Chloride-based products, but is only effective to about -7­­°C.  This makes it a good choice for parking garages where the temperature is usually close to freezing and every surface is concrete.  As a bonus, CMAc is vastly safer than salts to plants and animals, which could save developers thousands in sod, tree and shrub replacement.  It is a tricky balance, however, as CMAc is 20 to 30 times more expensive than rock salt.

     Potassium Acetate is so expensive that it's generally only used for infrastructure projects where safety is the highest priority, like airport runways, and cost is more or less irrelevant.  This product has good performance down to -20° and so makes good sense when environmental considerations are necessary in very cold climates like ours.

3. Blends

     When it comes down to brass tacks, the majority of deicing products are blends of the aforementioned compounds.  Always read the label before you decide what to use, and keep your needs in mind - fast melting, long-lasting, pet or landscape friendly, etc.