Choosing a De-Icer or Snowmelt Product
Tips for Dealing with Snow and Ice --
When it comes to removing snow and ice, everyone has an opinion about the "best" way to handle them. Timing is often as important as the method used, from de-icers to abrasives like sand, sawdust, clean clay kitty litter or fireplace/stove ash. Unfortunately, each has one or more downside.
As de-icers melt, up to 55% of the chlorine becomes part of storm water runoff, entering waterways where it can create toxic conditions for aquatic life and our drinking water.
Abrasives get tracked into our homes and wash into catch basins, eventually entering our rivers and streams causing sedimentation problems. What do the experts recommend?.. … Lay a wooden walkway over snow and ice. Use sand where a walkway is not feasible and be sure to sweep it up in the spring before it washes into catch basins.
Beyond these suggestions, consider the following information.
- For dry/powdery snow, sweep or shovel the snow as soon as possible.
- For heavy/wet snow, apply deicer as soon as snow begins falling to prevent it from bonding and creating an ice barrier.
- For sleet/freezing rain, apply deicer early to prevent build-up.
- For significant snowfall (more than two inches), shovel first and then put down the deicer.
- Move vehicles to expose as much driveway as possible after snow is removed. The black asphalt will act as a ‘solar collector’; clear a wider area than needed if possible to improve drying and drainage and reduce likelihood of ice patches.
If you need to use a de-icer, consider this information before you make a purchase. Most chemical de-icers work by melting the snow and ice to form brine. Brine breaks the bond between the pavement and the ice due to the brine's lower freezing point.
Five chemicals are commonly used as de-icers.
- Sodium chloride (rock salt - NaCl), which is the most common deicing agent. It’s been used for decades because it is inexpensive and abundant. More notably, it works because it is effective to about 25 degrees F.
- Calcium chloride (CaCl2) is effective at temperatures lower than 25 degrees. It comes in flake, pellet or liquid form and often out-performs other deicers due to its ability to give off heat as it melts.
- Potassium chloride (KCl) is effective at temperatures lower than 25 degrees but usually has a high salt index and is known to damage foliage and inhibit root growth.
- Urea is synthesized from ammonia, and has a lower potential to damage foliage than potassium chloride.
- Calcium magnesium acetate (CMA) is biodegradable and far less corrosive than traditional chloride based salts. It’s generally thought to be 10 times less corrosive than rock salt and when used as directed is safe for use around humans, pets, plants and turf. CMA contains dolomitic limestone and acetic acid (common vinegar) and although costly, up to 20 times more than road salt, it is a wise choice for use during relatively small applications needed around homes because it is salt-free.
If you choose to use rock salt, dilute it with sand, because rock salt is the most toxic of the de-icer products.
Apply deicers evenly using a broadcast spreader instead of scattering by the handful and select a colored product that can be easily seen on the ground to prevent over application.
US. EPA's Design for the Environment program permits manufacturers to put the DfE label on household and commercial products that meet stringent criteria for human and environmental health. A DfE logo on a product means that the product contains only those ingredients that pose the least concern among chemicals in their class. Unfortunately, the de-icers on this list are manufactured for bulk purchase such as orders from highway departments.
Many products claim to be environmentally- or pet-friendly.
Read the label carefully before you invest in a de-icer to ensure that you are getting the lowest possible chloride content.
Links to additional and more detailed information:
How to Choose a De-icer
Graphic Comparing De-icer Effectiveness vs. Cost
US EPA's Design for the Environment
Innovative Solutions for Highway Departments
Thoughts from Nebraska