Ice Melt: A Scientific Primer On Deicers
Safety comes first when deciding the best methods for removing snow and ice from sidewalks. However, determining what deicing chemical will work best for a specific customer takes a more sophisticated eye.
Don Walker, a professor in the engineering department at the University of Wisconsin-Madison, frequently works with deicing chemicals to determine their effects on surfaces. He says that often the person purchasing the deicing chemical faces the challenge of making sense of the manufacturers’ claims. “I’d be suspicious of products that don’t tell you what’s in the blend, because you don’t know what you’re getting,” says Walker.
Distributors can help end users wade through the claims that manufacturers make about their products. Like Walker, Dale Keep, owner of Snow and Ice Technologies Inc., Walla Walla, Wash., cautions: buyer beware.
For example, Keep takes issue with a product that is 98 percent salt (sodium chloride) and claims to have a freeze point of –75 degrees Fahrenheit, since it is impossible for rock salt to melt at that temperature.
“When you are buying a product, look at the basic chemical of that product and understand what that baseline is capable of,” says Keep. “Be sure to ask for data and verification and ask for independent data. The majority of products that are out there are good, but there are a few fly-by-night artists out there, too.”
There are some basics all distributors should know about deicing chemicals. They are composed of chlorides and acetates, and all have specific properties that lend themselves to specific weather.
While all ice melts offer customers varying levels of melting potential, there are a few general rules that are inherent to all chemical types.
First, before a solid deicing chemical can do any melting, it has to take on moisture and turn into a brine. People are actually always melting snow and ice with a liquid, Keep says.
The concentration at which chemicals work to melt ice depends on the ratio of that chemical compared to the amount of water in the brine. All chemicals have a “eutectic” point — the lowest temperature at which the chemical can depress the freezing point of water — and all eutectic points have a corresponding concentration percentage.
The chemicals also have a “practical” or “effective” temperature — essentially the temperature that the deicer will show results in a commonly accepted time range. All chemicals will work below this point, but at a slower rate that generally requires additional applications.
More isn’t always better when it comes to chemical concentration. Keep explains that straight water can’t serve as a deicer. Add some chemical and it gradually increases the solution’s ice-melting capability.
Use the concentration that is associated with the eutectic point and you reach the maximum point, but if you increase the amount of chemical in the concentration, the solution’s effectiveness quickly dwindles.
Working With Customers
With all of the ice melt options on the market, distributors say there are a few trends that they consistently see when assisting end users in making a deicer purchase.
“It’s usually price,” says Jack Lewis, general manager of Hubman Products, Galena, Ohio. “Schools want to keep [the grounds] safe and hospitals might be more concerned about damage to their grass and stuff like that, but it does usually come back to how much it costs.”
Lewis’ company sells sodium chloride and calcium chloride. In helping customers make a decision over which to buy, he typically talks temperatures. “You have a lot more freeze-thaw cycles with rock salt, which will damage your surface because you’re freezing and unfreezing,” he says.
While rock salt will melt to about 15 or 20 degrees, any time it gets warmer than that, the liquid thaws out, but when temperatures fall again, the liquid freezes once again. “They say calcium chloride melts down to about –26 Fahrenheit, so you don’t have those freeze-thaw cycles,” Lewis says.
A lot of the ice melt sales at Supply King, Neptune City, N.J., are based on bids, so prices also rank high in buying decisions. “Most of the time, it is a budget decision as much as anything else,” the company’s CEO, David Kawut, says. “Coming from the distributor end, we try to sell on the benefits of each [deicer], assessing the need of the customer.”
Facility type is often not as important as the dollar role when it comes to what kind of deicer a customer prefers. However, he has found that health care and educational facilities will buy blends, while office buildings tend to order straight potassium chloride or calcium chloride.
“In education and health care, you have pretty much around-the-clock type of operations and you need a product that lasts,” Kawut explains. “With an office building, you have people entering shortly after the custodial staff does, so they need a fast-melting product. And [businesses] have the budget for it. They’re looking for effect and they have deeper pockets.”
Kawut knows the benefits of each type of deicing chemical the company sells. This knowledge helps him to explain to customers the differences between calcium chloride (a fast melter) and potassium chloride, which is relatively safer for the environment.
Although the different chemicals do offer facilities different functions, Kawut says customers generally don’t buy more than one kind of product a season, even if one chemical would work much better in specific outdoor conditions than the one they have chosen.
“Generally, it’s all or none,” says Kawut. “The customer is going to purchase the one that they choose. They will not purchase a ‘mixed bag’ of product. They will not order two skids of one and two bags of another.”
Though budgets outrank many of the concerns for customers, Don Kellermeyer, president of Kellermeyer Co., Bowling Green, Ohio, says that some customers are willing to pay a premium if it means superior results. The company’s marketing department has developed a piece of literature for customers that breaks down the specifics of each type of deicing chemical it carries.
“The weather conditions really dictate what ice melt people will buy,” Kellermeyer says. “We try to give them the options, but they have to make up their minds. If it gets down to zero or below 20 degrees, we do remind people that they need to have something that will melt at a lower temperature than rock salt. They understand that.”
Obviously, the severity of the winter season dictates annual ice melt sales. The best weather for selling deicers, according to Kellermeyer, is when it is warm for a couple of days, then gets cold, heats up again and cools back down over and over.
“After a snow, you get the sidewalks looking good, and then it stays cold, but there’s no more snow or no more rain coming down, so they don’t really need much more ice remover on there,” Kellermeyer says. “It’s better when it thaws with a rise in temperatures and freezes again.”
To make sure the company doesn’t get slammed with demand when there is a storm, and to ensure customers get the best product for their needs, the Kellermeyer Co. works with customers early in the season to secure a good amount for their companies. “We have a pre-order sale before October, so they have to have their orders in and they can have delivery up to November 1 to get the pre-order price,” Kellermeyer explains.
Deicing chemicals, while good for providing safety to pedestrians outdoors, can wreak havoc on the concrete surfaces, indoor floors and plant life surrounding a building. While little can be done to prevent damage to outdoor surfaces other than knowing what chemical to buy and how much to use, protecting plants and indoor floors is a little easier.
Some grasses and shrubs are very sensitive to chlorides while others tend to be hardier, Walker says. “In planting and selecting plantings around areas where you will be using the chlorides, you should select plants that are going to be more chloride resistant,” he explains.
Ice melters do inevitably get tracked into facilities. “It is a mess, but if you’re going to provide a safe walking environment outside, I guess indoor building cleaning requirements are part of the challenge,” says Walker.
In fact, when Kawut talks with customers about their concerns with ice melt, he is never asked to discuss the function of the product. Instead, customers are concerned with the effect that it will have on the building.
The best way to lessen damage caused by deicers is to lay down mats. “People never have enough matting,” says Kawut. “If you removed outdoor materials from people’s feet, it would never come into the building. Matting is every facility’s best option.”
Other than trying to stop ice melt at the door, Kawut also says there are some neutralizer products on the market that are effective in removing residual ice melt.
“With ice melt, what you see is almost like a patina — a white powdery surface on a floor — which is tracked-in ice melt,” Kawut explains. “In order to cut that, you could use fresh water, but you have to change your mop water every two to five minutes, which no one will do. To boost that effect, we suggest using a neutralizer.”
When deciding between chemicals, Dale Keep, owner of Snow and Ice Technologies Inc., Walla Walla, Wash., notes that chlorides are more corrosive than acetates, but cautions that no chemical is 100 percent non-corrosive.
• Sodium chloride (NaCl)
• Magnesium chloride (MgCl2)
• Calcium chloride (CaCl2)
• Potassium chloride (KCl)
• Calcium magnesium acetate (CMAc)
• Potassium acetate (KAc)