The Dangers of Black Ice

black ice

Well, it’s that time of year again and it bears repeating to send out a reminder to all of our snow contractor customers to watch out for black ice again this year! There is generally no surface that is more dangerous than black ice and since it’s nearly impossible to see, you should know all you can about it so you know when it might be present and how to avoid accidents on it. Today we will explore all the details related to black ice.

First, how does ice form on hard surfaces?

It’s common knowledge that precipitation causes water, and water will freeze when the surface temperature falls below 32 degrees Fahrenheit. Remember, we aren’t talking about the air temperature, but the temperature of roads, sidewalks, driveways, parking lots, etc. Precipitation comes in many forms aside from just regular rain:

  • Snow: Even the thinnest snow cover can cause roadways and sidewalks to become slippery and dangerous if the surface temperature falls below 32 degrees.
  • Freezing Rain: Drops of freezing rain, whether it’s heavy or light can form a sleek coat of nearly solid ice on all surfaces. Have you seen what freezing rain can do to branches and cars? Imagine how dangerous it makes roads!
  • Sleet: Usually these small frozen pellets are one of the culprits that cause black ice when combined with freezing rain. Other times, they can dramatically reduce visibility when driving as they stick to windshields.
  • Fog: This can be one of the most unsuspecting creators of icy roads. Fog can be fairly innocent, just reducing visibility unless temperatures drop below freezing then fog can create ice!
  • Wind: When high winds cause snowdrifts, roads become extra slippery and dangerous to unsuspecting drivers who think roads are plowed and safe.

If you are located in an area where extreme winter weather is common every year like we do in the Mid-Atlantic region, it’s easy to become complacent. But when you are a snow and ice management company focusing on helping customers keep their properties safe after snow events, it’s important to remember that it’s not just snow that’s the problem. The bottom line is that ice can form quickly during multiple types of precipitation when combined with freezing temperatures. 

How Does Black Ice Form?

Black ice is more of a glaze than water before it freezes. Basically, it forms from light freezing rain or when snow, water, or ice melts and re-freezes on roads and surfaces. Black Ice is more likely to form around sunset or sunrise when temps fluctuate the most. But anytime there is thawing and re-freezing it’s time to watch out for black ice. Fog and freezing rain can contribute to the formation of black ice as well.

If you hit black ice when driving, it’s important to hold the vehicle steady without making any sudden movements. Stay calm and resist the urge to slam on your breaks. Instead, try to glide through it and look for areas where you can gain your traction back. Believe it or not, white snow is actually a great target to look for in regaining traction. Gravel, sand, and grass are other good options. In essence, you want to try and avoid black road surfaces that are likely to be covered with more black ice. Since black ice is virtually invisible, it will just look like a black, wet road.

Black ice will go away when surface temperatures go above 32 degrees naturally or when an ice melt solution creates the heat needed to melt the black ice. Pre-treating surfaces with a deicer such as Magnesium Chloride or Calcium Chloride can help prevent the formation of black ice.

How Ice Melt Products Work

Ice melt products and deicers interact with moisture to form a heat-generating slush called “brine” that melts the ice. Technically, the salt itself doesn’t melt the ice, but it creates a reaction that generates heat that will melt the ice. Ice melt products can be applied in a pellet, flake or liquid form. They can also be applied before, during or after precipitation has fallen. As the liquid brine spreads out over the surface it creates an agent that will help melt ice and/or break the ice bond to the road or surface so it can be cleaned up easier.

For snow and ice management companies that want to be proactive for their customers, it’s common to pre-treat surfaces with the brine. It’s common to see this is the form of dusty stripes on roads before the temps drop or before snow is predicted. By pre-treating roads, sidewalks and parking lots with liquid brine pre-treatment, it helps contractors removed snow and ice faster and with better results that end up creating safer surfaces for cars and people.

The concept for how ice melt products and deicers work is the same, but there is a wide range of effectiveness temperatures depending on the chemicals used. For example, if temperatures are extremely cold and down up -25 degrees, Calcium Chloride is the most effective bulk product to melt the ice. Magnesium Chloride, Sodium Acetate and Calcium Magnesium Acetate are used when temps are above 5 degrees. Potassium Chloride products are effective down to 12 degrees. And Sodium Chloride and most blends shouldn’t be used unless temperatures are above 20-22 degrees.

Another thing to consider is how fast different ice melt products start working. This is important to understand before choosing which ice melt or deicer product to use. Obviously it’s usually vital for products to start melting ice asap after being applied, but that isn’t always the situation especially with pre-treatment services. For example, calcium chloride and magnesium chloride are liquids in their natural states and tend to go back to being a liquid repeatedly. Even when they are used as flakes or pellets they quickly become a liquid brine that releases heat when they come in contact with moisture or precipitation. Once the brine is created, it creates more brine so it’s a very fast and reliable solution for melting ice on surfaces.

On the opposite side of the spectrum, both sodium chloride and potassium chloride are solid in their natural state. They still form into a strong liquid brine solution when they come in contact with water, but they must absorb heat from the environment to continue melting snow. That’s why they aren’t as effective in lower temperatures and they work slower than calcium chloride and magnesium chloride products.

Ice Melt Storage

Since water is needed for the ice melt to generate heat and break down into brine, it’s incredibly important to store ice melt products in dry areas. If moisture or precipitation hits your ice melt, it will activate it and start to form a brine and break down. The last thing you want is for your ice melt chemicals to absorb moisture in the air and start breaking down before you can use them.

Contact us at Snow & Ice Salt & Chemicals Unlimted, LLC if you would like to stock up on ice melt products or even if you need some last-minute supplies – We’re open 24/7, before, during and after the storm.


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